The Forbidden Universe: The Origins of Science and the Search for the Mind of God
Page 27
CREEPS AND JERKS
Almost incredibly, neo-Darwinism also has difficulty in explaining – of all things – the origin of species …
The theory of speciation says that when a beneficial mutation occurs, over the course of many generations natural selection carries the new trait to the rest of the species. Eventually so many changes from enough mutant individuals accumulate that a new species comes into being. The new species is genetically distinct from the original, to the point that it cannot breed with any members of the original species that might still be around. Given the air of confidence with which such matters are discussed in the public domain it’s surprising that evolutionary biologists can’t agree about how the processes governing speciation occur.
Different schools of evolutionary biology have proposed different models of exactly how speciation happens, but none of them can prove theirs to be correct. This is not surprising: it’s another of those areas where it is virtually impossible to acquire hard data. Evolution is such a long, slow process. After all, you can’t watch it happening in a lab, at least not where the likes of elephants, rubber plants or quantum physicists are concerned. There have been some instructive experiments on the micro level, with bacteria – particularly a long-running series with E. coli at Michigan State University – where different strains have changed their genetic make up over many generations. However, such experiments involve primitive species in glorious isolation facing limited survival problems, which hardly mimics the conditions of the real world.
All the scientists really have to work with is observation of the natural world and analysis of fossils, both of which are severely restricted. Contrary to expectations, the fossil record is not much help for the neo-Darwinian model, since many things that the theory would predict to be there are conspicuous by their absence. Darwin himself, in the words of palaeontologist Stephen Jay Gould, ‘viewed palaeontology more as an embarrassment than as an aid to his theory’.34 And eminent neo-Darwinian Ernst Mayr acknowledged in the late 1980s that following the fossil record:
… seemed to reveal only minimal gradual changes but no clear evidence for any change of a species into a different genus or for the gradual evolution of an evolutionary novelty. Anything truly novel always seemed to appear quite abruptly in the fossil record.35
More recently, Steve Jones, Professor of Genetics at University College, London, has stated that the fossil record ‘can look anti-Darwinian’, meaning many of the things that should be there just aren’t.36
These absences are contrary to all Darwinian expectations. After all, the most dramatic changes should take the most time to manifest, and should leave more fossil traces. Yet they are not there. It has to be assumed that this anomaly is due to the fragmentary nature of the fossil record.
True, we are left with the remains of a tiny fraction of all the animals and plants that ever lived, representing a tiny fraction of all the species that have ever evolved. Only about a quarter of a million different species have been found in fossils, whereas the number of species ever to live is probably up there in the billions. The fossil record is really a random sampling of evolutionary history. How random and how big a sample nobody really knows – palaeontologists are left floundering in a statistical gloom.
Others are not so sure that the leaps in the fossil record can be brushed aside quite so easily. Although most biologists maintain Darwin’s original view that evolution is a slow and gradual process, for a minority in the field – mostly palaeontologists – it happens in short, sharp bursts. These are the theories of quantum evolution proposed by George C. Simpson in the 1940s (which still has supporters such as Thomas Cavalier-Smith), and punctuated equilibrium put forward by Stephen Jay Gould and Niles Eldredge in the early 1970s. While the two theories agree the story of each species consists of long periods of stasis with short bursts of rapid evolution, their proposed mechanisms are quite different.
Critics of punctuated equilibrium have called it a theory of evolution by jerks; Gould responded that theirs is a theory of evolution by creeps. But punctuated equilibrium and quantum evolution do at least suggest why the fossil record offers scant evidence of the gradual metamorphosis of one species into another.
The major objection to quantum evolution and punctuated equilibrium is that they require a mechanism over and above ‘classic’ neo-Darwinism, implying that the current theory is incomplete – hardly music to the ears of most evolutionists.37 Other biologists argue the theory is missing something vital. British biologist Brian Goodwin declares:
… despite the power of molecular genetics to reveal the hereditary essences of organisms, the large-scale aspects of evolution remain unexplained, including the origin of species … So Darwin’s assumption that the tree of life is a consequence of the gradual accumulation of small hereditary differences appears to be without significant support. Some other process is responsible for the emergent properties of life, those distinctive features that separate one group of organisms from another – fishes and amphibians, worms and insects, horsetails and grasses. Clearly something is missing from biology.38
‘LOOK AT THE KING! LOOK AT THE KING!’
Most of the problems highlighted above would be solved if there were some way that natural selection could operate at the level of species, or even higher. Something that could see the big picture, in other words. But there is no place in neo-Darwinian theory for this. A species evolves because the individuals within it evolve. Natural selection does not work at the level of the species, or the gene, but the individual.39
We are told, with confidence edging into arrogance, that neo-Darwinism can explain everything in the biological world, and there’s no need to invoke anything else. However, as we have seen, it totally fails to explain:
The origin of life itself, specifically the origin of DNA.
The appearance of the nucleated, eukaryotic cell without which multi-celled life would be impossible. (A ‘special case’, the result of a process outside the usual neo-Darwinian model.)
The origin of sexual reproduction, another thing without which complex organisms couldn’t evolve. (Another special case that required a non-Darwinian process.) Not to mention how sex caught on, given all its disadvantages.
How ageing, the clearing out of the gene pool without which evolution couldn’t advance, came into being.
And – irony of ironies – Darwinism can’t really explain exactly how species originate.
Frankly, the Emperor is just plain naked. Nude. His only suit is the one he received on his birth day.
No doubt Richard Dawkins will be sighing as – or rather if – he reads this, ‘Here we have yet more non-scientists picking holes in Darwinism just because it can’t explain everything … so far at least …’ But there is an elephant in the room that is particularly difficult to miss. In fact, there are so many glaring flaws in the logic of neo-Darwinism that there is a whole herd of deliberately unnoticed pachyderms crammed into that one little space.
Darwinism performs a neat sleight of hand by using observations as explanations. Although perhaps an oversimplification, there is nevertheless some truth in the way that the great iconoclast of scientific theorizing and collector of strange phenomena, Charles Fort sums up the evolutionary message: ‘survivors survive’.40 It’s not so very different from the logic behind the quip: ‘Statistically, people who have the most birthdays live longest.’
Neo-Darwinians do have a penchant for seeking to explain all biological phenomena simply by describing them. Take for example convergent evolution – perhaps ‘parallel’ might be a more apt term – where two species widely separated on the evolutionary tree have independently developed exactly the same anatomical solutions to the same survival problems, without having inherited them from a common ancestor.
There is a plethora of impressive examples across the animal and plant kingdoms where organisms that look virtually identical are in fact completely unrelated genetically. Many of the most obvious are
found in Australia, which because it has been cut off from the other continents for around 50 million years, has developed its own idiosyncratic flora and fauna. In particular, marsupials rule, whereas in the rest of the world mammals with placentas have won the day. This has resulted in many Australian creatures that, fitting the same ecological niche as placental mammals, have evolved a very similar anatomy. There are marsupial moles, which look like moles from elsewhere, marsupial mice that look like non-Australian mice, and even an equivalent of the flying squirrel, the flying phalanger. Since marsupial and placental mammals diverged far back down the evolutionary tree, all of these have evolved completely independently.
But evolutionary theory also recognizes divergent evolution, where different species facing the same survival problems in similar environments come up with different solutions. Yet both types of evolution – convergent and divergent – are regularly cited as definitive proof of Darwinism. For example, New Scientist’s biology features editor Michael Le Page, wrote of divergent evolution in a 2008 article intended to counter the claims of the intelligent design movement, that ‘there is no reason why a “designer” would not have mixed up these features’.41 Dawkins also argues that the absence of shared features in distantly related species is evidence against intelligent design – no mammal has feathers, even though they would be useful to flying mammals such as bats.42 But convergent evolution is just the kind of mixing up that Le Page says never happens; according to his and Dawkins’ logic, convergent evolution must be evidence for design.
Even more bizarrely, Dawkins uses convergent evolution as an argument against intelligent design. He counters creationist claims that complex organs such as the camera eye of mammals – which is made up of separate components that individually do nothing but work perfectly together – could not have evolved by chance. Dawkins points out that the camera eye has actually evolved independently at least seven times (and eyes of any kind, based on other principles, at least forty).43 Not only is this a non sequitur – surely it just makes the problem seven times worse – but it also contradicts his argument that the lack of shared features in distantly related species disproves the existence of a designer.
Besides divergent and convergent evolution adapting a species to its environment, there is a third option: no evolution at all, or stasis. Judging by the fossil record, some species – ‘living fossils’ as Darwin put it – have hardly changed over vast tracts of time, including sharks, crocodiles, horseshoe crabs and horsetail plants. According to Ernst Mayr: ‘Some species are extraordinarily young, having originated only 2,000 to 10,000 years ago, while others have not changed visibly in 10 to 50 million years.’44
But why didn’t the living fossils change even a tiny bit over such an extraordinary length of time, when most species quite clearly have? Unsurprisingly nobody knows for sure. It is often said that the non-changers are just perfectly adapted to their environment (‘evolutionary complacent’, as British comedian David Mitchell puts it), but this is simply putting too positive a gloss on it. The evolutionary explanation is rather that it is because these smug species are so finely attuned to their environment that the slightest change means they can’t survive in their own little niche, so no changes ever get a chance to get going. They are trapped in an evolutionary dead end they can never break out of.
But many of these animals and plants are found in different habitats and live alongside other species that have continued to evolve. Sharks live in all the oceans of the world alongside a host of fishy creatures that have evolved way beyond them, and horsetails grow alongside other much more advanced plants. To say chance mutation has never thrown up genetic improvements for these species begs the question of why it obliged for most others.
And there’s no question that the conditions in which some of these living fossil species exist have changed dramatically during their existence. Fossil dragonflies from 325 million years ago look exactly the same as today’s. Dragonflies are considered to be among the first, if not the first, insects – indeed, the first creatures – to develop flight. And they have carried on happily unchanged, seeing the rise and fall of the dinosaurs 230 to 65 million years ago, the appearance of mammals 190 million years ago and birds 150 million years ago.
Today’s dragonflies have to survive against predators, chiefly birds and web-spinning spiders, but as the first creatures to take to the air, they didn’t have to contend with them originally. There were simply no birds, flying dinosaurs or mammals. Spiders with the ability to spin suspended webs to catch flying prey only appeared 200 million years ago. But dragonflies nevertheless survived throughout that time, and the appearance of those predators, without ever adapting. In other words, dragonflies 325 million years ago were fully adapted to life in the twenty-first century. This flatly contradicts the conventional notion of evolution being an ‘arms race’ between predators and prey.
All these examples demonstrate that evolutionary theory is so flexible that it, too, has the ability to adapt itself to any given situation. If two species in similar environments are different, that’s divergent evolution; if they are the same, that’s convergent evolution; if a species hasn’t changed at all, that’s stasis. It’s all OK. It all fits. Actually it doesn’t, but it will have to. Nothing is as evolutionarily complacent as evolutionary theory itself.
There are more examples of this reasoning. Many species have adapted so specifically to a particular habitat that they can survive there and there only. The evolutionary explanation is that the species has carved out its own unique niche and it alone is capable of exploiting it. This means that the species has no competition, and so it thrives. On the other hand, there are animal and plant species living in a wide variety of environments. In these cases, we’re told, evolution has favoured flexibility because that increases the chances of survival, as adaptation that is too specific puts all the species’ eggs in one basket.
So which is it to be: evolution tending towards increasing specialization or greater versatility? Naturally, the standard answer is that different things work for different species, so each case has to be judged on its own merits. It’s here that we begin to see the infamous circularity at work. Survivors survive. The eminent philosopher of science, Karl Popper, noted scathingly (his emphasis):
Take ‘adaptation.’ At first sight natural selection appears to explain it, and in a way it does; but hardly in a scientific way. To say that a species now living is adapted to its environment is, in fact, almost a tautology … Adaptation or fitness is defined by modern evolutionists as survival value, and can be measured by actual success in survival: there is hardly any possibility of testing a theory as feeble as this.45
This sloppy reasoning also prompted Popper to say (his italics), ‘I have come to the conclusion that Darwinism is not a testable scientific theory, but a metaphysical research programme – a possible framework for testable scientific theories’.46 He argued that Darwinism became universally accepted because:
Its theory of adaptation was the first nontheistic one that was convincing; and theism was worse than an open admission of failure, for it created the impression that an ultimate explanation had been reached.
Now to the degree that Darwinism creates the same impression, it is not so very much better than the theistic view of adaptation; it is therefore important to show that Darwinism is not a scientific theory, but metaphysical.47
Labelling natural selection metaphysical is, of course, an exquisite irony.
Even John Maynard Smith, a self-confessed ‘unrepentant neo-Darwinist’,48 declared his own distaste for the ‘belief that if some characteristic can be seen as benefiting a species, then all is explained’.49 But sadly that’s all we get from his peers.
Even being generous, the neo-Darwinian theory of evolution is nowhere near as solid as its proselytizers pretend. It has many more gaps and areas of astounding vagueness than they would ever admit to the public. It is, in fact, a startlingly anaemic theory, manifestly failing to exp
lain any of the really major events in the development of life on Earth. Its ‘explanation’ of much of the rest is no more than a description, backed up with circular reasoning that assumes the correctness of the theory in the first place. This is analogous to physicists claiming to have a theory of everything that was absolutely complete – except for its failure to explain gravity or the behaviour of subatomic particles.
Evolutionary biology is, surely, unique among the sciences in that it uses gaps in its knowledge to support its fundamental theory, arguing that, since nobody can prove it wrong, the theory must stand. It is less a theory than a default position.
Undeniably, molecular biology has made huge strides in understanding what makes living things tick, particularly the workings of DNA and genes. Although a multitude of mysteries still remain unsolved, the essential laws of genetics – how genes determine the form of an organism and govern its survival, and its role in heredity – have been thoroughly tested scientifically.
What has not been proven, and it is hard to see how it ever could be, is the proposition that random mutations in genes, and random mutations alone, drive evolution. Ever since Darwin, the basic argument has been that chance is responsible for evolutionary change because it must be, since self-evidently no non-chance factors can possibly exist. If some other factor was involved it would have to be, by definition, supernatural and everything must be explicable in mechanistic terms? There can be no suggestion of purpose, let alone design. From his ivory tower of certainty, Richard Dawkins writes in the final chapter of The Blind Watchmaker (1986) (his emphasis):
My argument [in this chapter] will be that Darwinism is the only known theory that is in principle capable of explaining certain aspects of life. If I am right it means that, even if there were no actual evidence in favour of the Darwinian theory (there is, of course) we should still be justified in preferring it over all rival theories.50