Download Examine the controversies surrounding the theory of Evolution. The

Examine the controversies surrounding the theory of Evolution.
The theory of evolution by natural selection, also known as the Wallace-Darwin
theory or simply Darwinism, is the basis of our understanding as to how complex life
forms arise. It is almost universally accepted by the scientific community as the only
theory which can explain the existence of organized complexity, yet it was accused by
many for nothing other than being wrong. Moreover, there are controversies
associated with evolution even within the framework of the Darwinism.
Historically, the most feverish scientific theory which rivaled Darwinism was
Lamarckism, the belief that acquired characteristics can be inherited. Although
scientifically crippled, it retains the advantage of being much more emotionally
appealing than nihilistic Darwinism to the minds of many people. Lamarckism was
not only rejected because no organisms have been observed to have Lamarckist
inheritance: Lamarckism also violates the central dogma of molecular genetics, as
well as the underlying principles of embryology to such an extent that if it were valid,
there would be little left of modern biology. The central dogma, which basically states
that proteins cannot be transferred to becoming proteins or nucleic acids, naturally
forbids the offspring from receiving whatever characteristics acquired in the lifetime
of its parent. That is to say, the phenotype of the parent is irrelevant
Even if it were possible that acquired characteristics of a parent can somehow be
untranslated into DNA and be passed on, Lamarckism would still be severely
hampered, due to its reliance upon preformationism, which is false. DNA is not
deterministic, not a blueprint, one-to-one mapping of a body. Although DNA inputs
information, development also depends upon the environment and not solely genetics,
and one could never deduce what an adult body would be like exactly from a
fertilized egg. Embryonic development which results in an adult body contains many
processes to form complex structures which make up the body, and these processes
depend not on the whole sets of genes which a particular cell contains (all cells of the
embryo are genetically identical anyway) but which set of genes is switched on for at
a particular time, which is dependent upon local chemical conditions, the locus of the
cell, its recent history and external environmental factors.
Darwinism is often said to be preposterous due to the improbability that complex
organisms, such as humans, can appeared on earth by random mistakes of DNA
replication, all the way from single cell organisms. Such doubts are totally valid,
except that evolution by natural selection is anything but lucky random mistakes.
Darwinism emphasizes the existence of evolutionary pressure due to ever-changing
environmental factors, and advocates, metaphorically, that there are good reasons for
humans to have evolved. Mutantionism, however, another scientific theory which
challenges the Darwinian theory by postulating that evolution is driven not by natural
selection, but simply by series of random mutations, stating that things exists as they
are by sheer chance, is not immune to such accusations. As Mutantionism argues
against the environment imposing factors which guide evolution, it must be saying
that organisms, so many of them so well adapted to their respective environments,
find uses for their newly mutated features by immigrating to an appropriate
environment. This, however, is inconsistent with fossils record informing us that the
vast majority of species that ever existed have been eliminated. Moreover, with the
average mutation rate, there must be much more species in the world today than there
are now, and indeed, the number of environments which are needed to sustain them
would probably be too great to be possible∗.
Evolution had not always been debated healthily under a scientific framework. Many
beliefs, or disbeliefs, about evolution and Darwinism derived not from scientific
evidence but through personal desire to have nature shaped to one’s own liking, for
religious, political or aesthetical reasons, and sometimes controversies are resolved by
violence. One example was Lysenkism, which, without going into the details, was a
dubious version of Lamarckist inheritance invented by Trofim Lysenko, who was
head of the institute of genetics in the Soviet Union, to improve crop yields. Lysenko,
supported by Stalin and later Khrushchev, denounced Mendelism as ‘bourgeois fascist
pseudoscience’ and decided to wage war against it, executing and imprisoning many
prominent Russian biologists. Lysenkism contributed to the tremendous backwardness
of soviet agriculture and caused famines in the Chinese Mainland where it had been
exported to.
On the other hand, folk beliefs about evolution are often not political but influenced
by religion and aesthetics. For example, many people, who, having accepted that
mammals have evolved from the fish, process a belief in their minds that there is a
ladder of heredity from fish to humans, with ‘lower forms’ such as dogs and cats or
even dolphins being evolutionarily closer to the fish than humans. This is of course
nonsense, a mere recital of the medieval great chain of being. All mammals share the
same common ancestor.
∗
If there are 10 possible outcome of a mutation, and it take 100 mutations to create something like an
eye, there that alone would results in 10100 possibilities. This number alone is more than the total
number of atoms in the universe.
In documentaries, we are often presented with video clips, aided by a commentary
and background music, where all sorts of marvelous creatures perform wonderful
tasks. We are portrayed that nature is wondrous and beautiful, with its insects,
protected by camouflage or mimicry, with complex or even metamorphosis’ life
cycles, some even living in highly organized societies, adapting to the most exotic and
hostile of environments, loyally tenacious to their designated roles, safeguards to the
undisturbable, tranquil order of nature. Its animals too, no less well adapted to their
business of running and predating, are praised for their valour, intelligence and honour,
in the same manner as people are in our society. Feeding the public with such
romanticized fancies, far from assisting true scientific understanding, deprives from
them their right to understand the indifference of nature and drives people towards
absurd, non-scientific beliefs. It is truly unfortunate that even scientists with no doubts
whatsoever about Darwinism fall under the emotional appeal of adopting a Calvinistic
approach towards biology. This undoubtedly contributed to one of the greatest
controversies in the Darwinian era, the debate on the unit of selection.
Despite strong evidence that the only true unit of selection is the gene, there are many
advocates that the unit of selection could be higher, for example in the level of the
organism, a group of organisms or even species. Higher selection units are much more
attractive to believe in: organisms whose genes all work together in a common goal to
keep its host alive, or a group of organisms helping others of the same species to
survive, in a cooperative, friendly and altruistic manner, must sound so much more
appealing than the selfish gene theory. However, there ought to be no room for this
‘Panglossian naivety’ (Dawkins 1982) in the true Darwinian synthesis. The truth is, of
course, that gene selection is neither altruistic nor selfish: these words are just
metaphors to aid understanding, although usually with opposite results. The gene
selectionist sees the bodies of individual organisms, rather than being a discrete,
indivisible unit, a mere vehicle where the true selection unit, the gene, resides,
temporarily in a geological time scale.
Individual selection, which advocates the organism as the unit of selection, is flawed
for the crucial reason that individuals are not replicators. It is not the bodies which get
replicated to the next generation but the genes, and indeed in sexually reproducing
species no other organism identical to its parent will ever exist. Furthermore, many
people are unaware that individual selection is fundamentally Lamarkist. To explain, a
body, which has poor chances of survival and is likely to be eliminated does not
necessarily process bad genes: perhaps it lost a body part due to an accident. By
emphasizing that natural selection differentiate at the level of the body, individual
selection is treating the blemishes of the unfortunate creature as though it were a
heredity unit.
Moreover, individual selection implies that natural selection favour bodies that are
strong, tough, enduring et cetera, must be absurdly suggesting that nature, which has
already received too much undeserved personification, can act as some kind of
invisible magistrate, who would how judge strong or whatever an animal is, and then
pass a judgment to it as to whether it deserves to survive. There is simply no criterion
of success for an organism. On the other hand, genes, as they are fundamental
heredity units, has no such problem as the sole criteria of success for a gene is simply
how good it is at making copies of itself numerous (something which bodies cannot
do). For example, genes that can distort meiotic secretion, manipulating meiosis to
one’s advantage, could be favoured by natural selection even if it harms the body. One
such gene in mice (called the t gene) is present in ninety-five percent of gametes of
any mouse that processes only one t gene, when the norm should be only fifty percent.
Despite when present homozygously causes complete handicap, it fares pretty well at
propagating itself under natural selection. This effectively disproves the hypothesis
that selection is at the level of the individual.
Most of the time, admittedly, genes are on the same boat as the vehicle and have very
similar interests to the vehicle at least until a certain age when it pays for the genes to
discard the vehicle. Individual selection therefore is often approximately equal to gene
selection. Group selection, however, is way off. A group of organism is not only too
unstable to be a discrete unit. It is far too vulnerable to cheating and betrayal by
individual members than a gene to the group of genes of a vehicle. Group selection,
supported by N. Eldredge and S. J. Gould, is often invoked to explain the origins of
altruism. The theory goes that groups which behave altruistically stood a better
chance of survival than groups that don’t, and over time only altruistic groups are left.
As already mentioned, altruistic groups are not evolutionarily stable enough to guide
evolution. A group whose members all behave altruistically are likely, over time, to be
invaded by a mutant who would exploit its peers’ services. The mutant would do
better on average than its peers as it could devote more energy to reproducing and
would soon out-compete altruistic members of the group. Only gene selection can
satisfactorily explain the origins of altruism.
A species is only a species because taxonomists classify them to be so. A species is
not a physical property, only a subjective label attached to an organism. In order for
species selection to work, organisms, for most of the time living before the age of
men and therefore taxonomy, must first become expert taxonomists themselves in
order to classify themselves into species, overcoming the ambiguity of
intermediateness and second, having become consciously aware of what species they
belong, strive together, in a spirit of brotherhood, for the welfare of the species and
the betterment of future generations; even then, it has only gone to the stage of group
selection. Nevertheless, such absurd implication that animals are feisty beings which
can conspire to improve themselves continues to be advertised in British schools,
unchallenged by generations of educationists. For example, the Nuffield Biology
Teachers’ Guide written for sixth from teaching happily preaches that ‘higher
animals… suicide to ensure survival of the species’ (Dawkins 1976), while questions
as bizarre as ‘explain the advantage of variation to the species’∗ (AQA 2004) are
commonly found among A-level papers.
Wrong to different extent, theories that bring controversy to the theory of evolution
share the same common naïve belief that organisms process deliberate intentions for
self-improvement and conscious awareness of the need to evolve. There ought to be
no big controversies surrounding the theory of evolution: only minor controversies,
well within the framework of the modern synthesis and consistent with our knowledge
of genetics and paleontology are actually valid. Unfortunately, myths often contain
features deemed virtuous by human society and triumph over orthodox evolution at
spreading for their easier understanding and greater appeal to the sentimental nervous
system. Hence, alternative evolutionary theories, having mutated into multiple forms
and fused with common folk beliefs, continue to be enshrined in our society. However
overwhelming the evidence, only when it is acknowledged by people that nature lacks
any purposes or meanings could the false impression that the theory of evolution is
controversial be extinguished.
∗
AQA (A) BYA5 Q9 b) January 2004.