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Abstract
The term biology is of Greek origin meaning the
study
of life. On the other hand, chemistry is the science of matter, which
deals
with matter and its properties, structure, composition, behavior,
reactions,
interactions and the changes it undergoes. The theory of abiogenesis
maintains
that chemistry made a transition to biology in a primordial soup. To
keep the naturalistic
‘inanimate molecules to human life’ evolution ideology intact,
scientists must
assemble billions of links to bridge the gap between the inanimate
chemicals
that existed in the primordial soup and anatomically modern humans.
Even though
the proponents of a natural origin of life expressed much optimism for
providing their theories, presently there is a detailed compilation of
information seriously questioning this doctrine. This reductionistic
ideology has
always failed to answer two simple questions: (1) What is the minimum
number of
parts that are essential for a living organism to survive? (2) By what
mechanism do these parts get assembled together? Evolutionists say a
series of
prebiotic processes and developments guide networks of dynamically
linked small
molecules and amphiphiles to form biological macromolecules,
membraneous
compartments, and finally primitive cells. However, none of these
proposed
pathways to life appears to be credible. The continuous advancement in
various
fields of science are not only providing major challenges to
reductionistic
ideology but are supplying increasing evidence for a systemic concept
of life as
an organic whole. Several leading researchers in the field of ‘origin
of life’ are
continually concluding that there are major scientific problems
attached with
all existing naturalistic ‘origin of life’ hypothesis. Only by taking
into
account all biological activities collectively as a system can a
satisfactory elucidation
of the living state be realized. In this present paper an attempt has
been made
to present a few significant challenges to the theory of abiogenesis
based on
the peer reviewed scientific literature. Subsequently, a
non-reductionistic
concept of life as a system is proposed as an alternative for resolving
some of
the problems inherent in origin of life research.
Introduction
The ‘spontaneous generation of life’ hypothesis
includes
a conspicuous history of unrelenting derision from several prominent
personalities
in science. At various times in its history, ‘spontaneous generation’
has been
identified by two different concepts. They are: (a) abiogenesis, and
(b)
heterogenesis. Abiogenesis is the field of science dedicated to study
how life
might have arisen spontaneously for the first time from inorganic
chemicals. On
the other hand, the notion that life can arise from dead organic
matter, such
as the appearance of maggots from decaying meat is known as
heterogenesis. For
a long time major western thinkers like Newton, Harvey, Descartes and
von
Helmont accepted heterogenesis with full confidence.
Francesco Redi by his experiments demonstrated
that
meat placed under a screen of muslin never developed maggots. The works
of
Schulze, Schwann, von Dusch and Schroeder provided significant
challenges to
heterogenesis, and finally in 1864 Louis Pasteur’s famous swan-neck
flask
experiment sounded the death knell for this theory. Pasteur famously
stated
that “Never will the doctrine of
spontaneous generation recover from the mortal blow of this simple
experiment”.
However, soon after establishment of Pasteur’s
famous
biogenesis theory, the reductionist school proposed an even more
intricate and
incredible form of spontaneous generation – abiogenesis. This
hypothesis gathered
its support mainly due to the collapse of the false dilemma of organic
and
inorganic matter (synthesis of urea in 1828 by Wohler), and the
development of
the concept of conservation of energy.
The modern form of chemical
evolution theory
began to develop following the proposal by Russian biochemist A.I.
Oparin. According to this claim, complex molecular
arrangements and functions of living systems evolved from simpler
molecules
that preexisted on the lifeless, primitive earth. Thus,
abiogenesis provided
an ideal sense of balance to Darwinian evolution theory, requiring
billions of
years to go from dead atoms and molecules to cells, and then, via
random
mutation or natural selection, from cells to the varieties of living
beings present
today.
Abiogenesis was popular for
years as an explanatory theory of self-assembly as the starting point
for chemical
evolution. Recently however, the abiogenesis hypothesis has been
experiencing
critical shortcomings and rapid advancements in cellular biology have
led
biologists to seriously doubt the veracity of this hypothesis. The present article aims at summarizing a few
crucial
scientific facts, which are leading us towards a paradigm shift in our
understanding
of the ontogenesis of life.
Primordial
Bombardments Dumped in Darwin’s ‘Warm Little Pond’
Charles Darwin (1809 –1882) proposed an
elucidation
for life’s origin that complimented his evolution theory. In a famous
letter
to
his botanist friend Joseph D. Hooker in 1871, he stated
“It is often said that all the conditions for
the first
production of a living organism are now present which could ever have
been
present. But If (and oh what a big if) we could conceive in some warm little pond with all sorts of
ammonia and phosphoric salts, light, heat, electricity etc. present,
that a
protein compound was chemically formed, ready to undergo still more
complex changes
at the present such matter would be instantly devoured, which would not
have been
the case before living creatures were formed.”
For more than one hundred
years this idea of Darwin’s was accepted dogmatically as scientists
were ignorant
about the primordial bombardments. In recent times however, scientists
have
come to believe that the earth’s first billion years witnessed
murderous bombardments
by large projectiles.-
Many leading scientists in the field of ‘the
origin of
life’ now feel that the hostile conditions of early earth warrant a
total
reconsideration of this preceding conviction. James Kasting, who
chaired a
Gordon Conference on the origin of life, and who was coauthor of one of
the key
papers dealing with the early bombardment, says that “The
field is in ferment.” An additional apparent confirmation of the same
can be
found from the first two paragraphs of the article ‘Goodbye to the Warm Little Pond?’, published in Science magazine:
“Ever since 1871, when
Charles Darwin made his oft-quoted allusion to
life’s beginnings in a “warm little pond,” scientists have tended to
imagine
the origin of life as being a rather tranquil affair-something like a
quiet
afternoon in a country kitchen, with a rich organic soup of complex
carbon
compounds simmering slowly in the sunlight until somehow they became
living
protoplasm.
Sorry, Charles. Your Warm
Little Pond was a beautiful image. It’s been enshrined in innumerable
textbooks
as the scientific theory of the origin of life. But to hear the
planetary
scientists talking these days, you were dead wrong. The Warm Little
Pond never
existed.”
Consequently, numerous new speculations are
attempting
to provide different explanation for the location of the origin of life
on
earth. There are several suggestions ranging from life beginning in
deep sea
thermal vents to bacterial life arriving from other places in the
universe
(Panspermia). Some of these hypotheses may be more credible than
others, but it
is an astringent fact that scientists have no existent evidence about
the
possible location for the first life on earth. Science
magazine also outspokenly substantiated that science has no
concrete answer to the question of how and where did life on earth
arise?
Chemical
Evolution Cannot Ride a Substantially Incredible Barbed Ladder
The chemistry of
prebiotic worlds is used on
the opposite side of the
defining moment for life, when Darwinian evolution theorized it first
started
functioning. It is perhaps
impractical that even the
simplest
existing cells could have evolved spontaneously, even more so that
exceptionally
complex modern life forms could have done so. To keep chemical
evolution alive,
chemists and biologists are utilizing the early earth data provided by
geologists and astronomers and are proposing numerous hypotheses in
support of
chemical evolution. Chemists select the likely prebiotic environment
projected
by geologists and study probable pathways for how organic molecules and
biomolecules could be manufactured in such an environment, how they
might have
interacted, and how this might lead to more complex living systems.
Biologists
more often than not see biomolecules in a slightly different context,
starting
from the high complexity of a modern organism and searching for the
vital
biological cycles and interactions and then trying to find how
something alike
but much more simple might have evolved. The open literature is
escalating with
theories on the origin of life.
Different theories claim different starting points. For example, some
propose
that life originated with template replicating polymers,
pyrites,
thioesters,
clays,,
polypeptides,-
and the claims are neither complete nor ending. Also, there is an ever
increasing list of speculations on the site of the origin of earth’s
first
life. For example, life originated in an oceanic thick soup, hydrothermal
vents, microscopic confinements,-, and again the speculations
are neither complete nor ending. From the scrupulous reviews,
we can realize the impractical range of speculative chemical evolution
theories
back from the chemistry of the existent cellular metabolism to the
chemistry of
the prebiotic world. The sections below present the vulnerable state of
the theory
of chemical evolution and its failure in outdoing the steps: (1)
Prebiotic
synthesis – Primordial soup, (2) Polymerization, (3) Pre-RNA World, (4)
RNA
world, (5) DNA/Protein world, and (6) Primitive cell.
‘Primordial
Soup’
with an Impossible Recipe!
Following Oparin, in 1929 John Haldane
proposed that in a reducing primitive atmosphere and with a suitable
supply of
energy, such as lightning or ultraviolet light, a wide range of organic
compounds might be synthesized.
According to Haldane, the primordial sea was the source of a vast
chemical
laboratory motorized by solar energy. Haldane explained that, in due
course of
time, the sea turned into a ‘hot diluted soup’ containing large
populations of
organic monomers and polymers. The term ‘prebiotic soup’ was coined by
Haldane,
and is well-known as Oparin-Haldane’s view of the origin of life. In
1953
Stanley Miller
offered experimental support for the theory of prebiotic evolution.
Miller
experimentally produced amino acids such as glycine, alanine, aspartic
acid,
and glutamic acid by passing an electric discharge through a gaseous
mixture of
methane, ammonia, hydrogen, and water vapor. Thus, he suggested that
the
implausible complexity in the molecular organization of living cells
might
someway have been produced from nothing more than simple chemicals
interacting
at random in a primordial ocean. However, we will see below in the
light of
scientific developments that, such a claim is far from the truth.
Thermodynamics
disagreement with Miller’s trick
Oparin, Haldane, Miller and his successors
suggested
unguided energy as the means by which simple molecules can be organized
into
more complex molecules. However, from the law of nature or from the
second law
of thermodynamics we know that order that emerges from undirected
external
forces not only has a momentary disposition, but does not get bigger,
unless a directed
external exertion is supplied. Miller’s explanations give us the
impression
that he may be ignorant about this fact. Random flashes of electricity
used by
Miller can transform simple molecules into more complex building
blocks. But
the very next moment, new electrical flashes supplied by him may
destroy these same
building blocks. The larger the building blocks, the faster they will
be
damaged. Hence, to protect building blocks from the destruction by new
flashes
of lightning, intelligent Miller
guided
the building blocks towards a distillation flask. In this manner clever Miller cooked a more and more
concentrated organic soup. Who had performed this inelegant
job of Miller’s in the primordial earth?
Chemistry
fails to convene the
demands of biology in primordial soup
The building blocks of life
formed in primordial soup exist only in extremely small amounts and
decompose
rapidly into a tar-like substance.
We
know that, the ozone layer in the upper atmosphere blocks harmful
ultraviolet
radiation. However, ozone is composed of oxygen and is the biggest
obstacle for
the synthesis of building blocks of the life like the ones obtained
from
Miller’s experiments. The chemistry does not function if there is
oxygen, but
if there is no ozone (O3) in the primordial
atmosphere, the amino
acids would be quickly destroyed by harmful ultraviolet radiation.,
Moreover,
‘chirality’ in biology demands chemistry to supply ‘left-handed’ amino
acids
and ‘right-handed’ genetic molecules. However, most of the chemical
reactions in
nature (except living organism) yield ‘racemic’ mixtures.
Reducing
environment fiasco
The idea of the primitive reducing atmosphere
has been
severely challenged by the available data from geology, geophysics and
geochemistry.,
There is no geologic evidence for either a reducing primitive
atmosphere or an early
earth containing large amounts of methane gas. Moreover, a quick
disappearance
of ammonia may take place, because the effective threshold for
degradation by
ultraviolet radiation is 2,250Å.
Also,
a quantity of ammonia equivalent to the present atmospheric nitrogen
would be
destroyed in approximately 30,000 years.
Experiments confirm that irradiating a highly reducing atmosphere
produces
hydrophobic organic molecules that are absorbed by sedimentary clays.
This indicates
that the earliest rocks should have contained an extraordinarily large
amount
of carbon or organic chemicals. However, this is not supported by the
observed
data. Based on observations from the stratigraphical record, Davidson
explained
that there is no evidence that a primeval reducing atmosphere might
have
persisted during much of Precambrian time.
Theoretical calculation also confirms that dissociation of water vapor
by
ultraviolet light must have produced enough oxygen very early in the
history of
the earth to create an oxidizing atmosphere.
Now for many decades it is well known that the
primordial
environment was most likely not composed of methane or ammonia, and
thus would
not have been favorable to Miller-Urey type chemistry. David Deamer, an origin of life theorist says, “This optimistic picture began to change in
the late 1970s, when it became increasingly clear that the early
atmosphere was
probably volcanic in origin and composition, composed largely of carbon
dioxide
and nitrogen rather than the mixture of reducing gases assumed by the
Miller-Urey model. Carbon dioxide does not support the rich array of
synthetic
pathways leading to possible monomers...”
Jeffrey Bada and his co-researchers also echoed the similar statement: “Geoscientists today doubt that the primitive
atmosphere had the highly reducing composition Miller used...”
Interestingly, it is reported in Earth
and Planetary Science Letters that chemical properties have
been
effectively unvarying over earth’s history, and thus concludes that “Life may have found its origins in other
environments or by other mechanisms.”
In 1996 Miller
himself stated, “We really don’t know what the
Earth was like
three or four billion years ago. So there are all sorts of theories and
speculations. The major uncertainty concerns what the atmosphere was
like. This
is a major area of dispute.”
Many
prominent scientists in recent time have discarded the Miller-Urey
experiment
and the ‘primordial soup’ hypothesis it claimed to support. In 1990 the
Space
Studies Board of the National Research Council suggested that origin of
life
scientists should undertake a “reexamination
of biological monomer synthesis under primitive Earthlike environments,
as
revealed in current models of the early Earth.”
In a
review, Leslie Orgel has expressed that, “The
relevance of all of this early work to the origin of life has been
questioned
because it now seems very unlikely that the Earth’s atmosphere was ever
as
strongly reducing as Miller and Urey assumed.”
In a
recent NPR report biochemist Nick Lane states that the primordial soup
theory
is now expired.
However,
this does not lead to an end to speculation on the
chemical origin of
life. Many new hypothetical primitive atmospheres have been proposed.-
It
is also speculated that organic compounds required for the origin of
life may
have come from outer space, for instance interplanetary dust particles,
comets,
asteroids and meteorites. However,
the
major question will be: was extraterrestrial organic material ever
efficiently
delivered intact to the Earth? Scientists
may
continually arrive at many such alternative theories about the unknown
past.
However, updated science textbooks should at least inform new
generations about
this now-outmoded recipe of ‘primordial soup’.
Polymerization
Riddle
Polymerization is a necessary process for
synthesizing
complex organic molecules (polymers) from simple organic molecules
(monomers). Biology
demands chemistry to supply not just any polymers, but very specific
ones. The
natural synthesis of amino acids and the development of peptides under
the early
earth atmosphere is one of the big problems in abiogenesis.
The
February 1998 special issue of Earth magazine also
states that, “And even if Miller’s atmosphere
could have
existed, how do you get simple molecules such as amino acids to go
through the
necessary chemical changes that will convert them into more complicated
compounds, or polymers, such as proteins. Miller himself throws up his
hands at
that part of the puzzle. “It’s a problem,” he sighs with exasperation.
“How do
you make polymers? That’s not so easy.””
Polymerization yields water molecules as one of
the
end products along with polymers. Le Chatelier’s Principle explains
that the
presence of a product (in present case, water) in the reaction medium
will substantially
slow the reaction. Darwinists proclaim that first life originated in
water over
a long span of time by a self-organization of molecules. The
equilibrium
concentration of biological polymers is sufficiently low and thus they
have a
propensity to break apart in water, not organize. Consequently, an increase
in time will only facilitate water to destroy the polymers. This crisis
is one
of the biggest headaches for the Darwinists.
To overcome this problem, polymerization in
primordial
earth requires dehydration synthesis. Because, the polymerization
process needs
an input of energy, some researchers proposed heating as a means to get
rid of
the water. However, many researchers including Miller himself reported
that a hot
prebiotic environment would accelerate the breakdown of biological
polymers and
hence this is not a suitable option for primordial biochemical
synthesis.,
Scientists are not able to know how the
earliest
biopolymers were formed in the prebiotic Earth. The characteristics of
such
polymers are so distinctive that it is impossible to conjecture about
their
development. Scientists can only evidently attempt various methods to
synthesize them under an assumed primordial-like environment. For
instance
chemists can only manufacture homopolymers or short co-oligopeptides,
but not
long co-polymeric chains.-
The Merrifield method can be adopted to produce amino acid by amino
acid, as identical
co-polymers. However, this is not a prebiotic technique.
A
range of remarkable reactions have been projected and considered in the
prebiotic scenario. However, the questions, ‘how to produce long and
chain
specific polymers under possible prebiotic circumstances?’, and ‘why a
specific
polymer chain was formed, and not a different one?’ are still
unanswered.
Chiarabelli also confirms that, “…it is
reasonable to agree with the statement, proposed by the editor, that we
do not
know, neither conceptually nor experimentally, how to make
macromolecular
sequences under prebiotic conditions.”
Therefore,
it appears to not be viable for scientists to overcome this
polymerization
riddle.
Pre-RNA
World – A
Jumbled and Gloomy Pathway to RNA
The primordial synthesis of self-replicating
molecules is a further and
more intricate problem than that of polymerization. In the 1980s
Noble-prize
winner Thomas R. Cech discovered self-replicating RNA molecules, and
thus
scientists started believing that RNA molecules could supply the
satisfactory
explanations for the transition of chemistry to biology in the
primordial environments.
However, soon researchers observed that there are too many problems
with RNA
for it to have been the molecule responsible for the transition from
chemical
to biological. As a result, scientists are now coming up with several
new
proposals for a variety of mechanisms and molecules by which the
transition
from chemical to biological can be explained in a world existing before
RNA. In recent years the pre-RNA world concept
created a
great interest among the origin of life researchers, in spite of the
absence of
direction from known metabolic pathways in biology regarding the
chemical
nature of a predecessor to RNA.
In 1966, Cairns-Smith came up with a drastic
proposal supporting that the
first appearance of life was not based on organic polymers at all, but
rather
on inorganic clays.
This
model explained the partaking of inorganic clays in creating a
replicating
system capable of storing information. Information was represented by
the distribution
of charges or shapes along the surface of the clay. On the other hand,
replication is meant to copy that information to newly formed clay
layers. The
role of natural selection comes into picture when the number of ions in
a layer
influences how quickly and efficiently the new layer can be made.
Suggestions
of these kinds not only force chemists to consider more broadly the
nature of
heritable chemical information, but challenge them to develop and
provide experiments
to investigate these proposals.
Researchers then started the search for
alternative
genetic materials. For example, Eschenmoser has proposed a molecule
called
pyranosyl RNA (pRNA) that is very much correlated to RNA but
incorporates a different
edition of ribose.
In natural RNA, ribose contains a five member ring of four carbon atoms
and one
oxygen atom. On the other hand, Eschenmoser’s ribose structure is
rearranged to
contain an additional carbon atom in the ring. Eschenmoser finds that
complementary strands of pRNA can unite by typical Watson-Crick pairing
to give
double-strand units that allow a smaller amount of undesirable
variations in
structure than are achievable with normal RNA. Furthermore, the strands
do not
twist around each other, as they do in double strand RNA. In a pre-RNA
world, where
protein enzymes were absent, twisting could stop the strands from
unraveling
cleanly in replication process. Hence researchers believe that, pRNA
appears superior
and more suited for replication in a primordial environment than RNA
itself. However,
scientists have yet to discover an effortless means for synthesizing
ribonucleotides containing a six-member sugar ring. Consequently, pRNA
failed
to gather sufficient experimental
support to be considered a strong candidate.
In a very different approach, Nielsen and his
team have
used a computer model to design a peptide nucleic acid (PNA) that
combines a
protein-like backbone with nucleic acid bases for side chains.
Similar to RNA, one strand of PNA can combine soundly with a
complementary strand.
Like RNA, PNA may be able to act as a template for the building of its
complement. Scientists are hopeful that perhaps PNA was involved in an
early
genetic system. Even though Aminoethylglycine has been synthesized in
spark
discharge reactions from nitrogen, ammonia, methane and water,
to
date the prebiotic synthesis of an entire PNA monomer has not been
achieved. Although
PNA is non-chiral, it is vulnerable to cross-inhibition of the opposing
enantiomers when directing the polymerization of activated
D,L-ribonucleotide.,
In addition, PNA monomers can go through an intramolecular N-acyl
transfer
reaction that would stop any predictable mechanism for their
polymerization.
Both
pRNA and PNA dependent on Watson-Crick base pairs as the structural
element
that makes complementary pairing possible. Researchers engrossed in
discovering
simpler genetic systems are searching for complementary molecules that
do not
depend on nucleotide bases for template-directed copying. In reality,
there is
no encouraging evidence that polymers produced from such building
blocks can
replicate.
Threose-based nucleic acid (TNA) is a recent
suggestion
and evolutionists believe that TNA might be better candidate for
pre-RNA world,
compared to other possible sugar-based nucleic acids.
TNA
is alike to DNA and RNA. In addition, it contains a simpler 4-carbon
sugar
called threose in its backbone instead of deoxyribose found in DNA or
ribose in
RNA. Threose is a simpler sugar than ribose. Advantageously, TNA also
displays superior
base pairing properties. Inspired by these properties of TNA, some
researchers
projected that TNA could be a long-lost predecessor to RNA. However,
there are
several technical problems attached to this proposal. In 2000 Leslie
Orgel
listed several of them in his paper published in Science
magazine.
“Nucleotides containing a tetrose sugar have
not been considered likely components of an early genetic polymer
because they
cannot be joined together by phosphate groups to give a backbone with a
six-atom repeat.” Orgel further reported that, “In
the alternative gradualist scenario, ribonucleotides were at first
substituted a few at a time and at random in TNA sequences. The
proportion of
RNA components increased over time from almost zero to 100%. The
information
present originally in the TNA sequence was, at least in part, preserved
in the
final RNA sequence. This attractive theory suffers from one major
drawback.
Introduction of a substantial number of ribonucleotides at random might
not
prevent replication of TNA, but it would almost certainly destroy the
catalytic
function of any particular TNA sequence and thus would render evolved
TNA
sequences useless when rewritten accurately as RNA.” That
means none of the
existing life forms today retain any TNA. Jeffrey Bada also points out,
“TNA suffers from the chirality quandary
associated with all sugar-based nucleic acid backbones. Although the
presence
of a 4-carbon sugar in TNA reduces this problem to 2 sugars and 4
stereoisomers, it remains a formidable challenge to demonstrate how
oligonucleotides composed of only Lthreose could be preferentially
synthesized
under pre-biotic conditions .... the selection of chiral sugar
component of TNA
would have required some sort of selection process to be in operation.”
The catalytic potential of
proposed predecessor of RNA (pRNA, PNA, TNA, etc) has not yet been
established.
Hence, every rational supposition regarding pre-RNA life must reflect
on
whether that preceding genetic system could have facilitated the
manifestation
of RNA.
The
RNA World Reverie
The term “RNA World” was
originally used by the Nobel Prize winner Walter Gilbert in 1986, in an
interpretation on findings of the catalytic properties of different
types of
RNA.
However, the notion of RNA as a primordial molecule can be found in
several old
published literatures.-
In the real RNA world observed in present
available
biological systems, RNA plays dynamic roles in catalyzing biochemical
reactions, in translating mRNA into proteins, in regulating gene
expression, and
in the continuous scuffle between infectious agents trying to
destabilize host
resistance systems and host cells shielding themselves from infection.
Even
though scientists have no understanding about how it works, they have
the tools
to carry on their examination of this existing RNA world and distill
their
understanding. On the other hand, the primordial RNA world is a made-up
age
when RNA exhibited both information and function, both genotype and
phenotype.
Thus, verities of unending speculations are continually coming forward,
attempting
to apply the data of the present RNA world to understand the primordial
RNA
world.
Astrobiologists investigating
the origin of life on Earth struggle with the question about the nature
of the
molecules that were the precursors for life. The molecular basis for
the
storage of genetic information in existing living organisms is
deoxyribonucleic
acid, or DNA. The instructions enclosed in molecules of DNA are
expressed by
the organism with the use of RNA to make proteins that, in turn, are
essential
to mediate reactions in the cell. In the absence of RNA, DNA would not
be
translated into proteins. Similarly, without proteins, the needed
reactions
could not be catalyzed. This has been the chicken and egg problem of
the naturalistic
origin of life from chemicals – “which came first – DNA or protein
molecule?”
Moreover, DNA is an extremely
out-sized and intricate molecule and is more stable when two strands
come
together to form the double helix. It cannot replicate without the help
of RNA
and enzymatic proteins to catalyze the essential reactions. DNA also
seeks the
help of proteins to unwind its two strands for replication and to keep
the
strands from getting tangled up during replication. On the other hand,
RNA is
often observed as a single strand of nucleic acids. Its backbone
structure is
produced in fewer steps than DNA. Moreover, as it is comprised of a
four letter
alphabet, it also can restrain hereditary information. In 1983, Cech
and
Altman, separately revealed that ribozymes enzymes could be made
exclusively of
RNA instead of protein. This has lent to the notion that RNA was the
primitive
information-storing molecule of preference. As discussed in the
previous
section, some researchers also consider that there were other molecules
even
prior to RNA (pre-RNA world) that were used by the first life forms.
Those that
think that RNA was the first molecule with this function assume that
RNA,
instead of proteins, could catalyze all of the reactions essential for
replication. They refer to the era when RNA exhibited this task as the
“RNA
World”.
All these appear attractive possibilities, but
researchers have reported a
number of serious problems associated with RNA world. At the outset,
the sugar
molecule that is required to produce RNA molecules is ribose. In an attempt to find the
chance development
of organic molecules in the laboratory, scientists failed to produce a
reaction
that could gave rise to a high yield of ribose in place of a random
mixture of
sugars.
Even
if they discover a natural reaction that can readily gives rise to
ribose in
large quantities, they would then have to face the issue of the fast
rate at
which sugars would have decomposed in primordial conditions. Stanley
Miller and
his research group have reported, “ribose
and other sugars have surprisingly short half-lives for decomposition
at
neutral pH, making it very unlikely that sugars were available as
prebiotic
reagents.”
Finally, if somehow sugars are manufactured, how would primordial life
have
selected the structure of sugar out of a mixture that was exactly half
“right
handed” and half “left handed”? There are many such practical problems
attached
with both the prebiotic synthesis and the stability of ribose.-
One of the major assumptions of the RNA world
hypothesis is that in the
primordial conditions, ribonucleotides spontaneously condense into
polymers to
form RNA molecules. Once RNA molecules have formed, by its catalytic
activity
to replicate itself a population of such self-replicating molecules
would
arise. “It is difficult to believe,”
says RNA World research scientist Steven Benner, “that
larger pools of random RNA emerged spontaneously without the
gentle coaxing of a graduate student desiring a completed dissertation.”
In
addition, researchers believe that even if RNA could have formed
spontaneously,
the spontaneous hydrolysis and other destructive conditions operational
on the
early Earth would have caused it to decompose.
Joyce and Orgel recommend
that “…myth of a self-replicating RNA
molecule that arose de novo from a soup of random polynucleotides. Not
only is
such a notion unrealistic in light of our current understanding of
prebiotic
chemistry, but it should strain the credulity of even an optimist’s
view of
RNA’s catalytic potential.”
Francis Crick confirms that, “At
present, the gap from the primal “soup” to the first RNA system capable
of
natural selection looks forbiddingly wide.”
Furthermore, RNA
fails to perform all of the functions of DNA sufficiently to support
replication
and transcription of proteins. Consequently, Leslie Orgel pointed out
the
inability of the RNA world: “This
scenario could have occurred, we noted, if prebiotic RNA had two
properties not
evident today: A capacity to replicate without the help of proteins and
an
ability to catalyze every step of protein synthesis.” Orgel further acknowledged that, “The precise events
giving rise to the RNA world remain unclear … investigators have
proposed many
hypotheses, but evidence in favor of each of them is fragmentary at
best. The
full details of how the RNA world, and life, emerged may not be
revealed in the
near future.” Consequently the RNA world
reverie appears to be dreadfully hopeless.
DNA/Protein
World
Dilemma
The RNA world notion discussed in the previous
section, claims that, in the beginning phases of evolution, RNA behaved
as both
template and catalyst. All existing biological organisms exhibit the
partition
of tasks between template and catalyst. In existing biological systems,
the partition
of tasks is an elemental property: DNA stores genetic information
whereas
proteins function as catalysts. However, scientists are struggling to
answer major
questions such as: how did the DNA/Protein world come about, why would
such
partition of tasks evolve in the RNA world, and which came first, DNA
or
Protein? Again, we find the ‘chicken and egg’ problem.
Proteins may seem superficially better than RNA
as
chemical catalysts due to their larger range of chemical moieties and
structural flexibility. On the contrary, due to the nonexistence of
mechanisms
for template directed replication, proteins are greatly substandard to
RNA for
the storage of genetic information. Because of the absence of the
29-hydroxyl
at its sugar moiety, as compared to RNA, DNA is usually not as much of
a
reactive molecule. Especially, DNA is significantly more resistant to
hydrolysis than RNA,
particularly in the presence of metal ions.
For this reason, time and again it is recommended that DNA has an edge
over RNA
as a means of genetic information storage.
Nevertheless, Forterre reported that the superior stability advantage
of DNA
could not account for the origin of DNA because the benefit of using
DNA for
information storage depends on the chance of evolving a longer genome,
which in
itself would not offer any direct selective advantage to the systems
that
included DNA.
There is also no apparent experimental confirmation indicating that DNA
is
substandard to RNA as a chemical catalyst.
The chemical properties of DNA do not inevitably support the conclusion
that
the function of DNA is limited to information storage. Takeuchi and his
research group asked the question, “Given
these considerations, we ask: What selective advantage could there be
for an
RNA-based evolving system to evolve an entity that is solely dedicated
to the
storage of genetic information, i.e., an entity that is functionally
equivalent
to DNA?”
The sequence of emergence of different types of
biopolymers during primordial evolution is an extremely controversial
issue.,
There is an impasse attached to both the cases: (1) proteins preceding
RNA, and
(2) RNA preceding proteins. In existing biological systems, DNA
synthesis is
fully reliant on RNA. For instance, the monomer units for DNA
synthesis,
2’-deoxyribonucleotides, are produced by the alteration of
ribonucleotides, and
the primers utilized to start DNA polymerization are
oligoribonucleotides. It
is observed that the catalytic portion of the ribosome, which produces
proteins, is made completely of RNA. This is the significant reason
touted for
proteins preceding RNA. If one accepts that RNA is an inferior and less
flexible catalyst than proteins, then the immediate question would be:
what is
the selective pressure responsible for the evolution of RNA catalysts?
Transitioning
from RNA to DNA as the hereditary molecule significantly enhanced
genomic
steadiness. This is believed to improve the possibility that a given
organism
or molecule would be around long enough to reproduce. Transmission of
the task
of primary catalyst to proteins also presents major advantages. Both
transitions provide understandable advantages to a ribo-organism,
nonetheless
in fundamentally different ways. Hence, both would manifest following
different
evolutionary pathways. If we presume RNA was the first of the three
macromolecules, an unsolved dilemma is which came next, DNA or protein?
Primitive
Cell – A Miniaturized
Walled City at Work
Darwin suggested that algae, amoebae and other
such simple
living beings were blobs of protoplasm which might have just appeared
in some
warm little pond by the chance combination of chemicals. Darwinian
ideology
imagines that a small number of relatively effortless changes in this
protoplasm could show the way to developmental alteration. Natural
selection
would make sure that better adaptation would be preserved. On the other
hand,
changes which led to poorer adaptation would die out. Scientists
influenced by
this ideology believe that natural processes produce complex life forms
from
simple ones, which in turn came from dead chemicals. Based on such a
foundation,
abiogenesis proclaims that the first life had arisen by a chance
accumulation
of chemicals. The same is evident from the statement of Julian Huxley,
one of
the most influential evolutionists, “Evolution,
in the extended sense, can be defined as a directional and essentially
irreversible process occurring in time, which in its course gives rise
to an
increase of variety and an increasingly high level of organization in
its
products. Our present knowledge indeed forces us to the view that the
whole of
reality is evolution – a single process of self transformation.” However,
the advancements of microbiology have helped the scientists to look at
life in
a better way. Darwin’s portrait of organisms made of a small number of
simple
chemicals has given way to one of astounding complexity even in the
simplest
living entities. The ordinary E coli bacterium has not only miniature
electric
motors of exceptional efficiency, but also the equipment to fabricate,
repair,
maintain, operate and power them with an electricity generating
mechanism.
Consequently, the notion of natural origin of
primitive cells in the primordial earth is being severely challenged by
the
modern explosion of knowledge in microbiology and cellular biology. The
issues
attached to the ‘natural origin of life’ doctrine will not come to an
end, even
if one assumes that the necessary chemical building blocks were
accessible in the
primordial atmosphere. Any theory of ‘natural origin of life’ on Earth
needs
the practical description of plausible pathways for the conversion from
complex
prebiotic chemistry to simple biology, understood by evolutionists as
the
appearance of chemical accumulation capable of Darwinian evolution. The
primitive cellular life requires a certain minimum number of systems,
like (1) the
means to transmit heredity (RNA, DNA, or something similar), (2) a
mechanism to
obtain energy to generate work (metabolic system), (3) an enclosure to
hold and
protect these components from the environment (cell membrane), and
finally (4)
a unique principle to connect all of these components together
(appearance of first
life). It is incredulous for evolutionists to believe that all of these
four systems
appeared simultaneously. Hence, the majority of followers of
abiogenesis
hypothesis are debating on the sequence of appearance of these events
in the early
earth. In the light of modern scientific advancements, the subsequent
subsections illustrate the major hurdles in the pathway connecting
chemical
building blocks and the primitive cells.
Centre
of unabated conflict: ‘metabolism first’ or
‘replication first’?
The origin of life theory should clarify the
origin of
the distinctive phenomena which maintains life, such as reproduction,
metabolism, and their corollaries (cell division, information carriers,
genetic
code, growth, maintenance, response to external stimuli, etc.). Reproduction is undoubtedly crucial
for the continuation of any form of life. For this reason,
evolutionists
believe some form of molecular
replication must have been started spontaneously in the
prebiotic
environment as a simple, entirely physicochemical form of reproduction.
On the
other hand, cellular metabolism is understood as a set of chemical
reactions
that occur in biological systems to maintain life. This vital process
helps
organisms to grow and reproduce, maintain, and respond to their
environments.
The metabolism process is classified in two different classes,
catabolism and
anabolism. Catabolism process produces useful energy and the anabolism
process
uses that energy to build components of cells such as proteins and
nucleic
acids. Through metabolic pathways, in a number of steps one chemical
converts
itself into another chemical by a sequence of enzymes. Enzymes are
essential
for the metabolic processes, since enzymes permit biological systems to
make necessary
reactions that require energy. Hence, some researchers believe in the
supremacy
of metabolism,,- and others assume
the supremacy of reproduction.,,,, Once again, scientists confront
the same difficulty, ‘‘which came first, the chicken (metabolism) or
the egg
(reproduction)?’’
The contest between proponents of ‘metabolism
first’
and ‘replication first’ persists unabated with both speculations
subject to
criticism. The ‘metabolism first’ speculation has been criticized by
some of
the prominent researchers in the field based on the judgment that major
steps
in the construction of such a metabolic scheme are exceedingly doubtful.,,,
The ‘replication first’ notion is also challenged, considering the
observation
that the de novo manifestation of
oligonucleotides is questionable, and that there is no apparent pathway
from an
RNA world to the existing dual world of proteins and nucleic acids.,
How
a primitive cell developed its skin?
Abiogenesis hypothesis must also supply the
means and
pathways for primitive cell growth and division, as well as the
mechanism by
which cells could take up nutrients from their environment. All
existing
biological cells are membrane enclosed workspaces. The cell membrane is
the
container which holds a cell together. It manages to retain an internal
milieu
different from its environment within which genetic materials can
reside and
metabolic activities can take place without being lost to the
environment. Existing
cell membranes on earth are made of composite mixtures of amphiphilic
molecules
like phospholipids, sterols, and several other lipids, plus
miscellaneous
proteins that carry out transport and enzymatic works. Modern
biological membranes
are pretty secure under different environments and can tolerate a wide
range of
temperatures, pH, and salt concentrations. These biological membranes
are
exceptionally fine permeability barriers, so that present cells have
comprehensive power over the intake of nutrients and the evacuation of
wastes
all the way through the dedicated channel, pump and pore proteins
implanted in
their membranes. Besides, immensely intricate biochemical machinery is
mandatory for the growth and division of the cell membrane in a cell
cycle. How
a structurally simple primitive cell could accomplish all these
essential
membrane functions in primordial earth is a difficult problem to
address. As
compared to the research efforts on replications and metabolism, the
starting
point of primitive membranes is one of the most neglected fields in
origin of
life investigations. While the unrelenting disagreements in abiogenesis
have
been around the ‘metabolism first’ versus ‘replication first’ issue,
there have
also been competing thoughts for the origin of the cell membrane. We
will
ascertain below that the attempts to produce biological membranes under
primordial earth are also suffering from multifaceted unsolved problems.
The experiments of Oparin’s,
and Fox on coacervates and proteinoid respectively were accepted as a significant historical step
in the
field of prebiotic synthesis of cell membranes. However, neither
coacervates
nor proteinoid microspheres have a factual boundary membrane that can
perform
as a selective permeability barrier. Coacervates and proteinoid are
prominently
detailed in present high school biology textbooks, even though they are
essentially unstable, lacking the capacity to supply a permeability
barrier,
and incapable of carrying metabolism. Consequently, the present
concentration
of research has transferred from colloid phenomena and protein
chemistry to
nucleic acids.,
Researchers proclaim that amphiphilic boundary structures contributed
to the
appearance of life on earth in primordial conditions.-
As an expansion of this view, some scientists suggest a ‘Lipid World’
situation
as an early evolutionary step in the appearance of cellular life on
Earth. Moreover,
some researchers have proposed that lipid membranes may have a
hereditary
potential because the majority membranes are produced from other
membranes but
not created de novo.,
However, these approaches have not received much attention, most likely
due to
the comparative scarcity of experimental evidence. Studies also claim
that, in
the middle of the abundance of the molecular variety anticipated to be
originated in prebiotic Earth, lipid-like molecules have a discrete
property.
That is: a capability to carry out spontaneous aggregation to form
droplets,
micelles, bilayers and vesicles contained by an aqueous phase through
entropy-driven hydrophobic exchanges.,
However,
the concentration of biomolecules in the aqueous primordial Earth has
been
expected to be roughly 1 micromolar,
essentially
insufficient for typical covalent chemical reactions indispensable for
formation
of hydrophobic and amphiphilic molecules.
Even if one ignores the difficulties in
connection
with the production of amphiphilic molecules in primordial earth, still
we are
left with several technical problems on the path of prebiotic synthesis
of
membranes. The physical and chemical properties of aqueous surroundings
can
considerably slow down self-assembly of amphiphilic molecules, perhaps
significantly restricting the environments in which cellular life first
emerged. For example, temperature significantly controls the stability
of
vesicle membranes. It has been suggested that the primitive life forms
were
hyperthermophiles that originated in geothermal regions such as
hydrothermal
vents
or deep subterranean hot aquifers.
However, under these conditions, the intermolecular forces that
stabilize
self-assembled molecular systems are relatively weak. Hence, such
locations are
not suitable for lipid bilayer membranes to assemble. There are also
several
similar restrictions attached with the ionic composition and pH of the
environment proposed for the origin of life.,
To
escape similar impractical situations, many
researchers are speculating that amphiphilic compounds existed in
carbonaceous
meteorites. These compounds might have self-assembled into membranous
vesicles
under suitable circumstances and were latter delivered to the early
Earth from
outer space by meteoritic and cometary infall.,
Even though lipid-like materials were claimed to be detected in the
Murchison
meteorite,,
successive research suggested that those compounds were contaminants,
rather
than endogenous materials. The
fabrication of appropriate biomolecules in the interstellar medium is
of no
significance to the origin of life unless these biomolecules can be
delivered
unharmed to habitable planetary surfaces. The major question would be:
can
these noble biomolecules withstand the brutal, scorching delivery to a
planetary surface? Even if in some way membrane building blocks landed
safely through
extraterrestrial resources, decomposition through hydrolysis,
photochemical
degradation, and pyrolysis would have drastically diminished the
quantity of
such materials.
Hence, we remain with the unanswered question: how did a primitive
cell develop its skin?
What
collectively linked the components in the first
living cell?
Despite
the massive advancements in the field of
cellular biology, the changeover from microscopic chemical mechanisms
to the
macroscopically evident emergent properties that illustrate life
remains
unanswered. Even if creation of an enclosed vesicle is achieved, it
does not
assure functionality of a primitive cell. In order to be practical as a
mechanism implicated in abiogenesis, membranes must be linked with all
the
materials indispensable to instigate life. A membrane must be capable
of
transporting material in and out of the boundary. Some type of
transport system
for nutrients and wastes would be compulsory to uphold the metabolism
of the
primitive cell. Moreover, both a primordial replicator and metabolic
system
must be interconnected in the primitive cell. Hence, such an
arrangement would
manipulate, generate and release the necessary chemicals during each
cycle.
However, it is uncertain what sort of equilibrium would ultimately need
to be
accomplished to make a transition from chemical system to a biological
system.
In a purely physicochemical sense, if a stable membrane is synthesized,
passive
transport systems can be easily arranged. However, such a provision
would robotically
attain equilibrium, making continuation of further transport
impractical.
Even
insignificant unicellular living entities are
self-guided and are utilize millions of special molecules dedicated for
specific responsibilities within a functional cell. Advanced cellular
biology
now confirms that a functional cell is made up of a sophisticated
network of
co-dependent biomolecules. Many of these biomolecules are only observed
in
biological cells and not anywhere else in nature. Robert Shapiro stated
in one
recent publication in Nature,
“In June 2005, a group of
international
scientists clustered around a small, near-boiling pool in a volcanic
region of
Siberia. Biochemist David Deamer took a sample of the waters, then
added to the
pool a concoction of organic compounds that probably existed 4 billion
years
ago on the early Earth. One was a fatty acid, a component of soap,
which his
laboratory studies suggested had a significant role in the origin of
life.

Over several days, Deamer took many more
samples. He
wished to see whether the chemical assembly process that he had
observed in his
laboratory, which eventually produced complex ‘protocell’ structures,
could
also take place in a natural setting. The answer was a resounding no.
The clays
and metal ions present in the Siberian pool blocked the chemical
interactions.”
Hence, those claims appear perverse which
suggest a
prebiotic existence of these biomolecules, which are only created by
life. Such
stubborn ideologists ignore the fact that biological systems display
astonishing accomplishments not because of an exceptional form of
chemistry,
but because a conscious creature can control chemical processes and
subordinate
them to a purpose intrinsic to the self-guided living being. Scientists
are only
making futile attempts at the moment to synthesize separately all the
essential
biomolecules by purely physicochemical means. The further and more
complicated
steps towards synthesizing functional cells are certainly beyond their
thinking.
A purely physicochemical transition from chemistry to biology is
impossible.
Recent experiments have already revealed a
biological
system containing in excess of 7 million protein sequences and over
50,000
protein structures.
Rapidly advancing cellular biology, especially metagenomics, assures
that
countless further molecular components are in the pipeline to be
revealed.
Biologists must give careful thought towards the principle that unites
these
large bio-molecular networks. It is suggested by scientists that the
potential
resources of energy for primitive cells are heat, chemical, and light
energies.
However, the major impasse is: how can unguided physical energies
manufacture a
state of such massive complexity and specificity as a living cell?
Srila
Bhaktisvarupa Damodara Maharaja (Dr. T.D. Singh) once asked molecular
evolutionist Stanley Miller at one of his lectures on the origins of
life at
the University of California, Irvine, “Suppose
you were given all the necessary cellular chemicals. Could you create a
living
cell in the test-tube?” Miller’s immediate answer was, “I do not know.”
Sripad
Bhakti Madhava Puri Maharaja, Ph.D. further made it more overt in an
online
discussion forum, “Anyone can take a
single cell and put it into a sterile test tube with all the necessary
ingredients to sustain its life. If you then puncture that cell with a
sterile
needle, the contents of the cell will pour out into the solution. Even
if you
wait for hundreds of years, life will not be generated from those
original
biochemicals of the cell. This tells us that life is not
simply cellular
in nature. The life principle is the apriori formative cause of the
cell or the
body of any multi-cellular creature. We can see this in action by
watching any
seed or egg or embryonic zygote go through its development to
maturity. Science cannot explain this development by simple
reference to
chemical activity.”
Hence, to seek the truth, sincere thoughtful scientists should make an
attempt
to understand the fundamental nature of life and thereby should reject
the tradition
of producing endless reductionistic speculation under the banner of the
chemical evolution of life.
Future
Research Suggestions to
Prevail Over the Fundamental Mistake
Biology
is misconceived as an amalgamation
of physics and chemistry
What
is the most fundamental particle that our
universe made up of? The reductionistic school has not yet figured that
out. In
the past, the atom was considered the most fundamental indivisible
unit.
However, later it was found to be made up of three particles: electron,
proton
and neutron. These days scientists are talking about further finer
subatomic
particles. Hence, there is serious doubt about the prospect of
scientists
settling down to a lasting finish regarding the most fundamental
particle that
our universe made of. Moreover, from the most fundamental particle (if
ever
scientists can manage to find one) to the functional primitive cell
level, life
forms handle extreme parallels and interactive courses of actions over
several
orders of magnitude of size. Without a proper understanding of the life
principle, biologists captured by the ghost of the naturalistic origin
of life
believe that they can explain this scale of complexity through purely
physicochemical means. Biologists conclude that it doesn’t matter what
takes
place within the organisms, for they can reduce all of that to
chemistry and
physics.
Using physics and chemistry, scientists try to
explain
the building of matter from atoms and molecules. The atomic relations
are
illustrated by chemistry. On the other hand, the lump of matter
produced from
an accumulation of atoms is explained by laws of physics. Based on
this,
biologists may argue that the whole matter of which a life form is
composed does
fit into the dominion of physics and chemistry. Based on this
impression, they
visualize that the protein–protein, protein–DNA or other bimolecular
interactions within a living cell are merely the outcome of physical
processes.
However, anyone can understand the distinction between living (animate)
objects
and non-living (inanimate) objects through a simple observation of
their
movements. The trajectory of motion of an inanimate object like a
satellite can
be predicted in terms of laws of mechanics. However, the motion of an
animate
object like a bird cannot be understood with the same principle. This
is
because an animate object is self guided. To stress the same idea we
would like
to present one more example: Newton’s first law of motion is applicable
to a
marble (inanimate object), but it cannot be applied to a tortoise
(animate
object). The motion of inanimate objects is determined by an external
force. We
need an external force to move a marble at rest. On the other hand,
animate
objects display a self driven spontaneous movement. A tortoise at rest
can
decide when it wants to move and no law in physics can determine that
decision.
By a simple observation of an organisms’ growth, irritability, reproduction,
metabolism, etc. one can make out
remarkable distinctions between animate and inanimate objects. Hence,
biologists must inquire about the deeper question: what automates the
animate
or living objects.
Following a reductionistic ideology, scientists
in
general invent novel laws using either a top-down or a bottom-up
approach.
External observation is the beginning point in the top-down approach.
Scientists by intuition envision a set of elements, a set of relations
and a
mathematically describable structure (equation) to unite the two.
Elements are
intertwined into a mental map, and experiments are premeditated to
validate or
invalidate the model. A law is established when the experimental
observations
repetitively substantiate the model under a set of different
environmental
conditions. The top-down approach (from imagination to observation) is
frequently used in physics. Newton’s laws of motion are the examples,
which are
developed following a top-down approach. On the other hand, the
bottom-up
approach starts by accumulating data on each and every element.
Properties of
components are experimentally examined in segregation and in alliance
with
other interrelated elements. Data collection is done under different
environmental conditions and patterns are studied. To confirm
observations,
experiments are repeated to determine consistent patterns. A law
manifests when
there is a substantiation of a consistent link among interacting
components in
different environmental conditions. Both bottom-up (from observation to
imagination) and top-down (from imagination to observation) approaches
are
commonly used in chemistry.
Searching for a consistent pattern is the
common means
in both top-down and bottom-up approaches. In non-biological systems we
observe
a consistent behavior of elementary particles, which is not the case in
a
biological system. Cellular interactions are inconsistent and
irreproducible.
A
living cell is a milieu of pure dynamic activity.
Due
to this reason we cannot apply top-down and bottom-up approaches to
develop
laws for a biological system. We may observe some consistent patterns
of
behaviors in living organisms. For example, by listening to the clap of
our
hands a bird close by will certainly fly away with a reliable degree of
predictability. However, it is impossible to explain this repeatable
pattern in
terms of a bird microarray profile before and after the clap. The
modern
researchers should recognize the fact that the molecular level
explanation is
undoubtedly insufficient to elucidate the complex activities of living
organisms.
21st
century biology – View
of organism as a sentient system
A bottom-up approach as discussed before was
used by Mendel
to deduce the laws of inheritance in biology.
Mendel
attempted to provide a molecular reason for the inheritance of traits,
which is
now known as the concept of genes. The modern synthesis of Darwinian
evolution
along with Mendelian genetics is known as Neo-Darwinism. Following in
Mendel’s
footsteps modern biologists attempted a total reduction of an organism
to its
genes. They are under the impression that knowledge of genes is the
knowledge
of the organism. However, it is a fact unnoticed in modern science that
Mendel’s
genetics meticulously overlooks vital features of the biological
system, or
life principle. Mendelian genetics attempts to provide an explanation
of an
organism by treating it as a combination of evidently distinct,
unchanging
traits. It does not address the developmental potential of the
biological
system, which allows it to interact with its environment and alter
itself depending
on varying conditions. Modern genetics fails to incorporate the plastic
propensities of a living organism. Moreover, Mendel used the traits
“yellow
seed” or “violet flower” etc., which are nothing but abstraction from
the whole
(pea plant). Mendel envisaged the responsible factors for inheritance
in the
form of inanimate objects. Like mechanical objects, these factors don’t
have
any internal relations. They have a superficial external relation.
Hence these
discrete entities cannot explain the inherent process of transformation
that
occurs in the plant right from germination of the seed until the death
of the
plant.
With the advancement of molecular biology the
concept
of chromosome, DNA, RNA, gene, etc came into the picture. Biologists
believe
that the gene is made up of a specific number and sequence of
nucleotides.
Furthermore, they consider that the sequence of nucleotide reveals the
message
of a gene. The central dogma of molecular biology was first formulated
by
Francis Crick in 1958.
This
central dogma attempts to provide a mechanism by which genes could
decide
traits through protein synthesis. This wishful thinking of rigid
mechanism for
a biological system can be sensed from the words of Crick: “a boundless optimism that the basic concepts
involved were rather simple and probably much the same in all living
things.”
It is a vision of oversimplification of the transfer of sequential
information
in an organism. According to this concept, sequential information in
biological
systems can only flow from the gene to the proteins and it cannot be
transferred back from protein to either protein or gene. Following this
idea,
geneticists proclaim that by the assistance of RNA, structure of DNA
can decide
the structure of proteins.
Central
Dogma: DNA → RNA → Protein
(Enzyme) → Trait
However, soon biologists recognized that the
transmission of biochemical specificity within the cell is
fundamentally
circular rather than linear. The ‘chicken and egg’ problem became the
biggest
challenge to this dogma.
It is observed that RNA is altered by enzymes prior to its information
being
translated into protein. Hence, there is no one to one communication
between
DNA sequence and proteins.
Researchers further confirmed that genes also switch their positions.
Additionally, based on the new position of the gene, its function might
alter.
Consequently, the position effect on genes revealed that genes are not
as rigid
to their context as had been contemplated.
The dynamic nature of genetic functioning is further confirmed from the
works
of Barbara McClintock. Her studies revealed that, the nature of
emergence of
different traits are greatly influenced by the movement of the gene.
Genes
are considered to be located in the chromosomes. To come up with an
explanatory
model, by considering DNA as the material foundation of the genes, some
researchers concentrate on the structural aspect of DNA. To construct
the
double-helix representation of DNA, its x-ray crystallography pictures
are
necessary. To achieve this, they place DNA in a crystalline form to
produce
such pictures. However, it is an unrealistic conception of the real
scenario.
DNA does not undergo crystallization in the watery environment of a
living
cell. In an organism, DNA is constantly constructed and broken down
during the
process of cell division, growth and death. Thus a few biologists have
now begun
to believing that a gene cannot be conceived as a mere molecule located
in the
cell. Thus, they think that the gene is a function that a cell has to
achieve.
Hence genes cannot be studied as objects or as molecules separate from
the
whole organism.
A
reconsideration in modern genetics is essential and biologists should
overthrow
the dogmatic believe that an organism can be reduced to its genes.
Reductionists misconstrue the organism by
identifying
it as the organs within the organism, the tissues inside the organs,
the cells
contained by the tissues, cell nucleus manufacturing the chromosomes,
various
substances in the chromosomes and finally the DNA. In such an approach
they
lose the context of the whole which is irreducible to simply the
component
parts. A biological system is a dynamic whole and is not a mere
accumulation of
parts. It is an inseparable unit of dynamic participants. Modern
biology is an
exceedingly valuable means to attain narrow, nevertheless very precise
knowledge. Considering the boundaries of this limited approach
biologists should overcome the habit of
conceiving
biological systems as a mere substances. They must know
precisely the
answer for the question: where does the real biology begin? In 1944,
directed
by the question ‘what is life?’, Schrödinger explained that biological
systems
cannot be nourished on energy as are artificial machines.
Considering the energy, matter and thermodynamic imbalances offered by
the
surrounding atmosphere, Schrödinger claimed that consuming negative
entropy is
a central necessity for the existence of life. Recent findings in
cellular
biology and advanced research on the behavior of bacterial colonies
confirm that
besides Schrödinger’s criterion of ‘consumption of negative entropy’,
‘consumption of latent information’ is an additional basic necessity of
Life.
Hence
all biological systems have to sense the environment and carry out
internal
information processing for surviving on latent information rooted in
the
complexity of their environment. Astonishingly, insignificant bacteria
can
effortlessly transfer inorganic substances into organic matter. To
achieve this
task bacteria employ chemical communication to create hierarchically
structured
colonies, made of 109–1013
bacteria each.-
Through cooperative action, they are capable of using any accessible
resource
of energy and imbalances in the environment to manufacture the
spontaneous path
of entropy creation. Thus they produce life sustaining organic
molecules for
themselves and for the usage of all other organisms. The essential
elements of
cognition in such sentient biological systems can take into account the
interpretation
of chemical messages, distinction between internal and external
information,
and also the ability to discriminate between self and non-self. These
cognitive acts of bacterial colonies include coordinated gene
expression,
regulated cell differentiation and division of responsibilities.,
Communally, bacteria can collect information from the environment and
from
other organisms, interpret the information in a meaningful way, build
up common
knowledge and learn from past experience. The bacterial colony works
very
similarly to a multicellular organism
or a social community.
Due to high complexity and plasticity, the colony can exhibit superior
adaptability to any encountered growth circumstances.
In order to attain the appropriate balance of individuality and
sociality,
bacteria communicate by means of a large collection of biochemical
agents.
Each individual in the colony also possesses complicated intracellular
signaling mechanisms which include signal transduction networks
and genetic language.
These capabilities are employed to produce built-in meaning for
contextual
interpretations of the chemical messages and for creating suitable
responses.
Biochemical messages are also utilized to exchange meaningful
information
throughout the colonies of diverse species, and also with new organisms.
Ben Jacob and his research group thus state that, “…we
reason that bacterial chemical conversations also include
assignment of contextual meaning to words and sentences (semantic) and
conduction of dialogue (pragmatic) – the fundamental aspects of
linguistic
communication. Using these advanced linguistic capabilities, bacteria
can lead
rich social lives for the group benefit. They can develop collective
memory,
use and generate common knowledge, develop group identity, recognize
the
identity of other colonies, learn from experience to improve
themselves, and
engage in group decision-making, an additional surprising social
conduct that
amounts to what should most appropriately be dubbed as social
intelligence.”
Ben Jacob and team also outlined how intra-cellular self-organization
jointly
with genome plasticity and membrane dynamics might, in principle, offer
the
intra-cellular mechanisms required for these fundamental cognitive
functions.
They stated that, “In regard to
intra-cellular processes, Schrödinger postulated that new physics is
needed to
explain the conversation of the genetically stored information into a
functioning cell. At present, his ontogenetic dilemma is generally
perceived to
be solved and is attributed to a lack of knowledge when it was
proposed. So it
is widely accepted that there is no need for some unknown laws of
physics to
explain cellular ontogenetic development. We take a different view and
in
Schrödinger’s foot steps suggest that yet unknown physics principles of
self-organization in open systems are missing for understanding how to
assemble
the cell’s component into an information-based functioning “machine”.”
The present engineering tactic is to construct
the
mechanical systems following a pre-designed plan to achieve fashionable
and
financially viable ways of satisfying the predetermined preferred
objectives.
Such machines can execute a narrow range of definite odd jobs by
connecting the
parts that are accurately pre-designed and manufactured based on a
particular
plan. The design plan aims to achieve the maximum accuracy by utilizing
minimum
essential parts, without any scope for randomness and errors. Although
such an approach
is effective and prevailing in modern engineering applications, it
cannot be
used to assemble cognitive biological systems (living cells or
organisms).
Biological systems are excessively complex. Participants in a
biological system
are flexible, with a high degree of randomness, and might be
uneconomical from
the current engineering prospective. Nonetheless, scientists in the
recent past
began realizing that authoritative properties exist that provide the
necessary
complexity and allow biological systems to execute novel jobs as
necessary.
These special tasks are unattainable by existing engineering means. To
comprehend properly life and its origin, scientists have to overcome
this
reductionistic mindset. At the moment they are under the false notion
that
biological systems are also governed by the same laws of logic that are
applicable to mechanical and chemical systems. It is therefore
essential to
properly grasp the distinction between mechanical, chemical and
biological
objects. What is the difference between a rock, a salt and a living
cell?
Sripad Bhakti Madhava Puri Maharaja, Ph.D. has given a cogent
presentation of
this difference in his article “The logic of life”. In conclusion of this present
section we are presenting those differences in a tabular format below.
|
Mechanical
System
|
Chemical
System
|
Biological
System
|
System
analysis
|
Mechanical system has separable, independent
parts. Parts are fully understandable outside their connection within
the system of which they are parts.
|
Parts of a chemical system are both independent
as well as dependent. Parts can be isolated separately and then can
also be added together. Parts cannot be understood without its relation
with another part.
|
Those parts that can not be separated from a
system without destroying it as a working system, can no longer be
called parts but are participants or members of a dynamic whole.
|
Relationship between system
constituents
|
(1) Parts are related externally.
(2) Parts do not have an internal relation.
Example: Planets relate to each other
externally by gravitational force in the solar system. Gravitational
force is also dependent on mass of the planet and not on the
composition of the planet.
|
(1) Parts are related internally.
(2) External relations are formed due to the
intrinsic properties of the individual parts of a chemical reaction.
Example: An acid (say HCl) is intrinsically
related to an alkali (say NaOH), which combine to form a neutral salt
(say NaCl).
|
Participants of a biological system exhibit an
internal teleological relation.
Example: In the absence of RNA, DNA would not be
translated into proteins. Similarly, without proteins, the needed
reactions could not be catalyzed.
|
Identity
|
(1) Parts retain the same identity when
connected within and isolated from the system.
(2) Parts are complete in itself without
reference to another part.
Example: The identity of a planet is not
dependent on other planets of the solar system.
|
(1) Parts display singular identity when
connected within and isolated from the system.
(2) Part’s identity or definition as an
isolated entity is incomplete and can only be understood in its
relation with another part.
Example: A substance is acidic only in relation
to alkaline substances.
|
(1) Participants do not possess isolated
identities.
(2) Participants are identified only in their
mutual relations.
Example: The constituents of a living cell
(DNA, RNA, Protein, Enzymes, etc) only retain their identities when
they are the participating members of a functional cell and not
otherwise.
|
Unifying
principle
|
External forces
|
Chemical bonds
|
Sentience
|
Conclusions
A biological system is not a machine-like a
gathering
of superficially assembled parts. A serious attempt is very much
essential towards
a new comprehensive understanding of the concept of the biological
system as a
whole. In a biological system the participants are dedicated to the
whole, and
the whole too, survives in each of its participants. As explained
above, many contemporary
researchers have already started recognizing each organism as a
sentient unit
or organic whole. This can be understood as the scientific confirmation
of the
ancient Eastern Vedantic
philosophical concept of atma,
Aristotle’s
concept of Soul and Hegel’s explanation of Concept. Vedantic
scholars, Aristotle, Kant (using the argument of
teleology) and Hegel all claimed that biological systems (organisms)
are
distinct from inanimate objects (mechanical and chemical systems). Purpose
and meaning are inseparable aspects of life. We cannot expect those in
dead
molecules. We don’t give any moral and ethical importance to an
accumulation of
dead molecules, but such a consideration is a must to the life
principle.
Hence, abiogenesis is an insult to the life force. There are several
ethical
problems attached to abiogenesis.
Scientific
recognition of sentience in the organisms has seriously dented the
reductionistic picture of the organism as a mere accumulation of
biochemicals. Advanced
scientific research is continuously providing an abundance of new
scientific
data. However, all of that has failed to provide any tangible
elucidation as to
what actually constitutes consciousness and what are its factual
characteristics.
Abiogenesis, Darwinism and post-Darwinism do not have sufficient tools
to accommodate
cognitive phenomena in a sentient biological system and hence they do
not have very
promising prospects. Therefore, both origin and evolution of life must
be
rewritten on the basis of sentience. Objective evolution is a
misconception
that biologists must overcome and should instead find the proper tools
to
explain the evolution from the realm of sentience. The book Subjective Evolution of Consciousness
composed by Srila Bhakti Raksak Sridhar Dev-Goswami Maharaja will be an
appropriate
guide for this endeavor.
The participants in a biological system come
into view
or grow out of the germinal organism and reveal the manner in which the
biological system as a whole relates to its environment. This
establishes that
life can only come from life. Moreover, evidently each species of life
produces
their unique biochemicals. The inanimate objects (dead chemicals) don’t
display
sentience. Sentience is a unique property observed only in biological
systems
(animated objects). This in turn establishes the fact that there must
be an
original sentient being from whom the life forms and their related
matter have
emerged. This is also a confirmation of the Vedantic
conclusion depicted in the second aphorism of the Vedanta
sutra and its commentary in the first verse of Srimad
Bhagavatam: janmady asya yato
'nvayad itaratas cartheshv abhijnah svarat – the
origin of everything is “abhijnah svarat”
– the unitary Supreme Cognizant Being. These interesting advancements
in modern
science are leading us towards an authentic scientific understanding of
the reality
of nature and origin of life. For the benefit of humanity, sincere
scientifically minded scholars should overthrow the misconceived
reductionistic
ideology of deep rooted materialism, and should carry forward further
studies
on these purely scientific, rational explanatory viewpoints.
Acknowledgements
This E-book is a humble offering to our divine
spiritual master Srila Bhaktisvarupa Damodara Maharaja (Dr. T.D. Singh)
on the occasion
of his fifth annual disappearance anniversary festival on Vijayadasami
(6th
October, 2011). This humble offering is only made possible by the
divine force
of the affectionate guidance and continuous encouragements we are
receiving
from our Siksha Gurudev Sripad Bhakti Madhava Puri Maharaja, Ph.D. We
also pray
for the blessings of our divine masters Srila Bhakti Sundar Govinda
Dev-Goswami
Maharaja and Srila Bhakti Nirmal Acharya Maharaja so that this humble
attempt
may attain its actual goal. We sincerely acknowledge the editorial
support provided
by Sripad Matura Nath Prabhu, Sripad Brajeshwara Prabhu, Sripad
Jagadananda Prabhu and Sripad Purushottama Jagannatha Prabhu, Ph.D.
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