Friday, January 13, 2023

Rebutting Eight Myths About Darwin's Theory Of Evolution


                                    Au. garbi, hominid ancestor of modern day humans

Rebutting assorted criticisms of evolution, especially the human version, is in many respects like playing 'whack-a-mole'. This is on account of the fact ignorant, anti-evolution creationists and intelligent design (ID) fanciers have engineered whole-cloth lies and deceptions about it, e.g.


The Sundry Ways That Anti-Evolutionists Misfire 

 In the process, they've roped in millions to believe their insane nonsense of 'Adam & Eve', a 6,000 yr.-old Earth etc. merits being taught alongside evolution. It doesn't: it merits being put into the nearest dumpster with their other swill.

So in this extensive post, culled from creationist objections I've encountered for over 40 years, I want to highlight some of the most common myths perpetrated about Darwinian evolution. In many respects I already covered one several blogs ago, that was concerning the "missing link". So now we will look at some others.

1. If Evolution’s true then why don’t we see apes evolving into humans?

This myth errs in not recognizing that humans, apes and monkeys are all distant cousins, as opposed to species in the same SINGLE evolutionary path. Humans don’t come from apes but from a common ancestor that was neither ape nor human in the distant past. Also, it overlooks the algorithmic branching basis of evolution, see e.g.

Thus, multiple evolutionary offshoots (as shown above) confirm no (single) primate evolution is based on a single path. Thus in the past seven million years there have evolved multiple hominid species including Homo Habilis, Homo Erectus, and Homo Neanderthalis- all of which went extinct along the way- except modern humans or Homo sapiens. Meanwhile the idea of current apes evolving to humans totally turns this algorithmic-convergence on its head, and proposes a singly determined evolutionary path!

Less well known is the crucial role that dentition analysis and tool making play in sorting the fossils of prehistoric humans. For example, one of the first questions the investigator will ask is whether a given jaw and teeth found in it, can accommodate flesh eating. For some fortunate cases, this is also answered by the fossils found in the vicinity of the hominid ones. For example, in the case of one Au. garhi fossil (see image of this hominid) an antelope jawbone was found nearby and on it ancient cut marks disclosing its tongue had been sliced out using a stone tool. Radio-nuclide dating of both fossils traced them to the same time.

Obviously, genetic testing is the optimum or gold standard. In one of the most powerful ever demonstrations of the validity of human evolution, Yunis and Prakash, 1982, Science, Vol. 215, p. 1525, 'The Origin of Man: A Chromosomal Pictorial Legacy', showed that the human chromosome designated '2' was the result of the telomeric fusion of the two ape chromosomes, 2p and 2q. The effect also saw the reduction from 24 chromosome pairs in apes, to 23 pairs in humans. In other words, the duo of ape chromosomes (2p and 2q) can be considered prima facie evidence that humans and apes share a common descent.

2. No one’s ever actually seen evolution occur!

In fact, we do observe evolution happening especially with organisms (e.g. fruit flies, viruses, bacteria) that possess short reproductive cycles. The problem arises because creationists treat micro-evolution disparately from macro-evolution. Because they don't regard the former as part of a continuum leading to the latter, they consider "macro-evolution" the only genuine form. (By “micro-evolution” we mean minute evolutionary change, involving a small proportion of DNA. For example, the emergence of an orange-eyed fruit fly (drosophilia melanogaster) after 20 generations would demonstrate microevolution.)

Macro-evolution entails a proportionately large change in the DNA underlying it that probably reflects ongoing natural selection, over significant time. For example, the change from a cold-blooded dinosaur to a warm-blooded dinosaur that’s a precursor of modern birds would be a case of macroevolution.

The point missed by the Creationists (or perhaps they never processed it in the first place) is that it is hundreds (or thousands) of micro-evolution transitional components that engender macroevolution, whereas creationists think they are two totally distinct aspects that are unrelated. Once one accepts the two are integrated into one interwoven process then one can accept that we DO see evolution actually occurring as when fruit flies have altered their wing shape or eye color after 20 generations!

Once more, the key aspect that shows micro-evolution is real evolution is the fact that gene frequencies are observed to change (along with the fitness) as time goes on. Thus, it is not simply like "breeding cattle" or different species of dogs (for which many varieties may actually see the gene frequency alter in negative directions, with fitness reduced).

To fix ideas: gene frequencies help determine the success (and progress)  of natural selection. In natural selection there is a genetic "favoritism", as it were, for certain species' traits or characteristics to be passed on or selected out of a group of competing traits in the gene pool. In more technical terms, preferential alleles appear by virtue of their relative increase in gene frequency.

Two quantitative measures for success of natural selection are the fitness (w) and the selective value (s): These can be measured on either absolute or relative scales, but are related algebraically on the latter by:

w = 1 – s, or s = 1 – w

As an illustration, consider a cockroach species (Blattella germanica) with allele D, where D denotes resistance to the pesticide dieldrin, and d denotes non-resistance. In the population after some defined time, let three genotypes be exhibited in the population: DD, Dd and dd.  Now, on average over time let each dd and Dd individual produce one offspring, and each DD produce two. These average numbers can be used to indicate the genotype’s absolute fitness and to project the changes in gene frequency over succeeding generations. The relative fitness (w) is meanwhile given by:   w = 1 for DD

w = 0.5 for Dd

w = 0.5 for dd

The selection values, or relative measures of the reduction of fitness for each genotype, are given respectively by:

s = 1 – 1 = 0 for DD

s = 1 – 0.5 = 0.5 for Dd

s = 1 – 0.5 = 0.5 for dd

As we expect, the dieldrin-resistant genotype displays zero reduction in fitness, and hence maximum survival rate. By contrast the d allele can be regarded as ‘deleterious’. Indeed, it can be shown that over successive generations of roaches, the gene frequency (of d) will decrease by:

D q= -spq2/(1 - sq2)

Here p is the frequency of the favored allele, and q the frequency of the disadvantaged (‘deleterious’) allele. Let’s say at a particular time a gene frequency ‘snapshot’ of the cockroach population under study yields: p(D) = 0.60, q(d) = 0.40, i.e. the favored allele D is reproducing at the ratio 3:2 relative to the disadvantaged one, d. Then one can work out how the alleles' frequencies vary over multiple generations. Of course, since the fundies - most of them- can't do simple algebra, this will be beyond them they will never accept it!

3) Evolutionists claim the process occurs by random chance.

Not so. Natural selection is not “random” nor does it operate by “chance”. What happens is that once a particular mutation is stabilized, then natural selection preserves the gains and eradicates the mistakes (to enhance better adaptation). Meanwhile, "chance" would be like me sitting a monkey down in front of a type writer or computer keyboard and hoping there is some "chance" it will type out at least one page of coherent script. But since a monkey will likely not recognize any key - or even if it does, then make a connection to words, or how to compose them into articulated thoughts - this isn't likely. It all rests on CHANCE!

Meanwhile, natural selection rests on preferred steps each of which consolidate former steps while advancing the adaptation. Thus, the eye evolved from a single light sensitive spot in a cell to the complex organ we behold today not by chance but rather by thousands of intermediate steps – each preserved because they assured better adaptation if incorporated, and hence a better eye. Many of these steps can still be observed today in simpler organisms.

Richard Dawkins perhaps put it best:

"What natural selection does is to consolidate particular random mutations into a more stable, adaptive adjustment – governed by deterministic factors and inputs. Thus, that while the selected trait often appears at random, its preservation in the gene structure cannot be relegated to randomness”

Again, his distinction between deterministic and random factors and inputs is perhaps too subtle for creationists and their ilk to comprehend. After all, most have never taken even a high school biology course, far less a college level one.

4) The Second Law of Thermodynamics disproves Evolution

This myth commits at least two fundamental errors:

(a) The error which assumes that evolution means more primitive organisms develop into more complex or organized ones, and, 

(b) The error that the second law (because it refers to increasing disorder or "entropy") applies to all living things- hence it is impossible they can "evolve" to more orderly, organized forms.

Consider (a) first: At no point and no place do evolutionists claim that more organized forms are the inevitable manifestation of natural selection and adaptation, and represent evolutionary success.What evolution states,which any high school biology student learns, is that the species which survive best are the most well adapted to their environment.

Thus, the humble cockroach beats just about all other species on Earth for evolutionary success given it's been around for 150 million years. Humans, though much more complex and organized than cockroaches, have only been around in their modern form for barely 1.5 million years, if that. Humans, up to now, have enjoyed  barely 1/100 th the evolutionary success of the cockroach, measured in time!

Now, as to (b), this is a common error of those who've never taken advanced physics, but just read Googled excerpts. It's basically a direct result of misinterpretation of the 2nd law, something I often see from those who've never taken a serious physics course. Strictly speaking,  the law states:

Entropy (the state of disorder) will tend to increase over time in any closed system

This is generally expressed in statistical mechanics terms as:

s = log g

Where 'g' denotes the number of accessible states. In other words, in a closed system we will expect the probability of increasing entropy and that means increasing accessible states.  This was discussed at length when we looked at assorted spin systems (see the series on 'Order and disorder' earlier this month) and noted that 
higher entropy - as in a state with low excess spin- corresponds to the most probable state. Say a  closed magnetic spin system S(2), has 10 spin ups while S(1) has five, then S(2) has a much higher degree of order (less entropy) than the system S(1). 

The part about closed systems is very crucial since it is exactly the part that the creationist-ID crowd omits, which renders their complaints using the 2nd law non-starters. The reason is that neither the Earth nor its biological systems are "closed" systems, hence do not exhibit constantly increasing disorder. The Earth, for example, receives a constant input of radiant energy from the Sun - quantified as some 1360 joules per square meter per second. Plants on the Earth are likewise OPEN to solar energy, and receive it and then use it in the process of photo-synthesis.

Since Earth is an open-dissipative system then at any given time for any subsystem, entropy may decrease and order increase, thus life may evolve without violating any natural laws.

Bottom line: so long as the Sun is radiating its energy, life can continue thriving and evolving. (Thus, more highly organized organisms such as humans have had the capacity to emerge, by dint of this input energy which they've been able to consume and retain - if only briefly).


5) Only an Intelligent Designer could have made something as complex as the eye

Richard Dawkins originally shot this specious reasoning down when he observed:

"This kind of default reasoning leaves completely open the possibility that, if the bacterial flagellum is too complex to have evolved, it might also be too complex to have been created. And indeed, a moment's thought shows that any God capable of creating a bacterial flagellum (to say nothing of a universe) would have to be a far more complex, and therefore a more statistically improbable entity than the bacterial flagellum (or universe) itself - even more in need of an explanation than the object he is alleged to have created"

At the very minimum, advocates of such a complex intelligent designer should at least have provided the necessary and sufficient conditions by which its design operates, but they haven't even done that.

Secondly, the anatomy of the eye certainly doesn't bespeak the existence of any kind of intelligent designer, but rather more the outcome from an algorithmic process. For example, it's built upside down and backwards- with photons of light having to actually travel through the cornea, lens, acqueous fluid, blood vessels, ganglion and amacrine cells, horizontal and bipolar cells, before reaching the light sensitive rods and cones that convert the light into neural impulses. (Which are then sent to the visual cortex at the rear of the brain for processing into meaningful patterns).

For optimal vision, why would an intelligent designer have built an eye upside down and backwards? Further, why on earth create it with a blind spot? What kind of "intelligent" design is that?

Far from a "designer" being in any way involved, the human eye betrays the pathways and structures that naturally would result from an evolutionary dynamic based on natural selection!

6) Too Many Gaps Exist in the Fossil Record for Evolution to be true.

This is a common myth, but it ignores that fact we have hundreds of intermediary fossils, such as for Archaeopteryx (one of the earliest known fossil birds with reptilian skeleton and feathers). We also have the records for a number of Therapsids, the intermediate species between reptiles and mammals. We also have the intermediary record for Tiktaalik – an extinct, lobe-finned fish fitting between fish and amphibians. Not to mention records to piece together a very coherent picture for the elephant (see diagram)

Further we know (based on fossil evidence) there are at least six intermediate stages in the evolution of whales and a dozen intermediate stages since the hominids branched off from the great progenitor common ancestor apes 6 million years ago.

In any case, as I also showed in many previous blogs, fossil record evidence does not make up the entire evidentiary constellation for evolution. We also have genetic evidence for common ancestry, for example of chimps and humans – as revealed in both having exactly the same cytochrome-c protein sequence – for which the odds are unfathomably remote (1 in 10 to the 93rd power) to be mere coincidence.

Of course, none of this will make a dime's worth of difference to fundamentalist creationist, because they don't adhere to scientific reasoning but only what's in their 2,000+ year old scriptures.

7) Evolution's only a theory and we know theories aren't real

This myth is based on a simple misconception of what constitutes a theory, actually confusing it with conjecture or speculation. In fact, a theory is the most advanced articulation of the scientific process: it represents the phase at which a hypothesis has actually been found to meet its predictive tests, and been confirmed. Thus, all branches of science are based on theories. For example, in physics we have the modern quantum theory (which explains the origin of the spectral lines in atoms, as well as their energy levels) and the theory of general relativity - which accounts for the action of gravitational fields near massive objects.

A theory is considered robust and reliable if it consistently predicts new phenomena that are subsequently observed. Facts then, are the world's data, and the theory of evolution is replete with them, including: the fact that humans and chimps display the same cytochrome-c protein sequence, and the fact that the 2p and 2q chromosomes in apes have undergone telomeric fusion to become the single '2' chromosome in humans. Thus, theories represent explanatory ideas about such facts we behold.

Speculations, meanwhile, are nontestable statements that are not strictly part of science. The "intelligent designer" is such a speculation until such time the ID backers can come up with not only an explanation for its nature (especially the necessary and sufficient conditions) but also describe specific tests by which we may confirm its existence.

Unlike the speculation of the ID, the theory of evolution meets all the criteria of good science, including:

- It's guided by specific natural laws and principles

- It is explanatory by reference to these self- same natural laws and principles

- it is testable by way of using those laws and principles - against the actual patterns, constraints of the empirical world

- It is not only testable but also falsifiable using tests

By contrast, no ID proponent has yet informed us how to falsify any of his claims, not one! Until he does so, he can't be said to possess the most remote semblance of a theory. What he is then advocating is a religious belief.

8) Evolution Can't Account for Morality

In fact, the most recent research into primates shows that morality of a sort isn't peculiar to humans - as one find self-sacrifice and sharing behavior in monkeys, as well as in dolphins, gorillas, whales, and elephants.

As a social primate species, humans also evolved a deeep sense of right and wrong, probably emerging during the transition from the hunter-gatherer culture of the Stone Age to the Agricultural milieu. Because humans in the latter framework depended on reciprocity and cooperation to get crops harvested and that meant sharing the bounty for all. This stability for the purpose of shared work also required strict moral codes to preserve the cohesion of the group and its survival. Thus, certain behaviors such as selfish hoarding, rape, theft, or wanton aggression were unacceptable. Current evidence suggests human morality was in place on this basis long before the first religions appeared.

Thus it was that evolution created the social and moral sensibilities and emotions that inform us that lying, adultery, murder and stealing are wrong because they destroy the the trust in human relationships contingent on truth-telling. No "Ten commandments" was needed.

Nor would it be possible for a social primate species to survive without some inborn, evolved moral sense. Without that moral sense, for example, no outrage would be expressed at the rape and torture of others, and because of this incapacity, the unique cohesion and order binding human societies would soon be destroyed. Our recognition of the pain and suffering of others is a direct outgrowth of these evolved moral emotions, not an invented "god". Especially the one sought out by fundies in their scriptures who can approve wholesale genocide without batting an eyelash (if he had one!)

Contrary to religious fabrications, it is the evolved moral and ethical sensibility which enables us to empathize with the suffering of our fellows while also recognizing that such suffering inflicted by peer aggression is wrong. We need no god to tell us this, and what religions have done is merely to appropriate the natural moral sense and smother it with hundreds of religious platitudes, scriptural mandates and rules. Thus, on the evolutionary constitution of a moral human nature is built the stable constitution of human societies. Those which tend to forget that, or allow temporary tendencies such as greed blind them, will pay the price by not surviving.

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