In my previous post (An Interview with Lynn Margulis), I discussed the unconventional and fascinating ideas of Lynn Margulis, one of the world’s foremost biologists before her passing in November 2011. I pointed out that Margulis was an evolutionist. I wrote in the second paragraph of the post that
Margulis held an unusual position on biological evolution. A fierce critic of the Neo-Darwinian paradigm, she nonetheless subscribed to an evolutionary picture regarding the emergence of the myriad life-forms on Earth today.
Later in the post I mentioned again that Margulis is an evolutionist. I also provided the link to the interview with Margulis, in which she states that she is an evolutionist – “… all life comes from a common ancestry…”.
Nonetheless, a fuming reader wrote in indignation that… Lynn Margulis believed in evolution. No, really?!
I suggest the following exercise. Read the original post and Matt’s comment on it, and then come back. Here is what the post was about.
In contemporary evolutionary biology, speciation (the process by which one species allegedly becomes two) is absolutely crucial. Yet there is not a single reliable, documented instance of speciation. Margulis rejected Neo-Darwinism partly because of this. Besides her comments on Darwin’s Finches which I featured in the previous post, Margulis makes the following point in the interview:
…neo-Darwinists say that new species emerge when mutations occur and modify an organism. I was taught over and over again that the accumulation of random mutations led to evolutionary change – led to new species. I believed it until I looked for evidence.
Margulis makes two arguments about speciation. Firstly, there is not a single unequivocal, documented instance of speciation – Darwin’s Finches don’t cut it. Secondly, Neo-Darwinism requires that biological organisms be infinitely-plastic – just pile mutation upon mutation and you’ll eventually get a new species. Margulis explains why this is unrealistic:
This is the issue I have with neo-Darwinists: they teach that what is generating novelty is the accumulation of random mutations in DNA, in a direction set by natural selection. If you want bigger eggs, you keep selecting the hens that are laying the biggest eggs, and you get bigger and bigger eggs. But you also get hens with defective feathers and wobbly legs. Natural selection eliminates and maybe maintains, but it doesn’t create.
All laboratory studies of mutation and all instances of selective breeding end in the same way. When you go beyond the enhancement of minor traits – slightly larger crests in pigeons, slightly larger milk production in dairy cows – you get defective creatures (or a spontaneous reversal to the original genome of the organism). This is hardly a promising path for the evolution of more fit organisms, and constitutes a devastating critique of Neo-Darwinism.
Beyond speciation, which was the focus of my previous post, Margulis makes two points which are relevant to Genesis and Genes.
Discover: Why do you have a reputation as a heretic?
Margulis: Anyone who is overtly critical of the foundations of his science is persona non grata. I am critical of evolutionary biology that is based on population genetics…
This is something that I discussed at length in Genesis and Genes. Scientists, like all people, resist the envelope being pushed. They are comfortable making modest progress working within a paradigm, but not when the paradigm itself is challenged. The history of science furnishes us with numerous examples of creative scientists who were ridiculed and professionally-isolated when they opposed the reigning paradigm. Whether it’s Lynn Margulis, Robin Warren, Daniel Schechtman, Ignaz Semmelweis, Alfred Wegener or countless others, radical ideas are often rejected for no better reason than dogma. The lesson for informed consumers of science is that when critics of evolutionary biology are ferociously set-upon by members of the establishment – with charges like “creationist” flying about, you needn’t get upset. To be charged with “quote-mining” is merely an indication that your interlocutor has little up his sleeve beyond Law 101 – when you don’t have a case, impugn your opponent.
Here is a final important point to emerge from the Margulis interview and which was covered in Genesis and Genes – how mathematics can sometimes hamper scientific progress, by providing the reassuring gloss of numbers and equations to otherwise vacuous endeavours. In Genesis and Genes, we saw how mathematics was used in the latter part of the 19th century to obscure the fatal weaknesses of various methods of dating the Earth. I used the term mathemagic – coined by David Klinghoffer of Discovery Institute – to describe this phenomenon. Here is Margulis on the subject.
Discover: You have attacked population genetics – the foundation of much current evolutionary research – as “numerology”. What do you mean by that term?
Margulis: When evolutionary biologists use computer modeling to find out how many mutations you need to get from one species to another, it’s not mathematics – it’s numerology. They are limiting the field of study to something that’s manageable and ignoring what’s most important. They tend to know nothing about atmospheric chemistry and the influence it has on the organisms… They know nothing about biological systems like physiology, ecology, and biochemistry… Evolutionary biology has been taken over by population geneticists. They are reductionists ad absurdum.
In other words, mathematics in population genetics is like the proverbial lamppost. It’s convenient to search under its light, even though you lost your coin elsewhere.
Readers are welcome to read the entire interview with Margulis (it’s only a few pages long and is non-technical) and see for themselves whether I misrepresented her views by quote-mining or anything else. The interview can be read here: http://discover.coverleaf.com/discovermagazine/201104?pg=68#pg70
When evolutionary biologists present evidence for the veracity of their claims, they do not present all their evidence all at once. The claim that focussing on one element of the debate is somehow unfair is ludicrous. Speciation is a pillar in the edifice of contemporary evolutionary biology, and it is perfectly legitimate to examine it in isolation from other claims. Even in a book-length treatment of the subject – Genesis and Genes – I explained that it was impossible to look at all the evidence:
A complete review of the evidence used by evolutionary biologists would fill up several volumes. Nonetheless, one can form an impression of the level of evidence from a few examples.
What we have seen about speciation is extremely important in this context. Yes, evolutionary biologists claim that there are many avenues of evidence which prove their point. But speciation is such an important part of the story, and the evidence for it so flimsy, that, as an informed consumer of science, the correct posture to adopt about evolution is extreme scepticism.