Friday, 8 November 2013

"20 scientific facts seldom taught to students" critically reviewed #4 A Christadelphian quote mines Charles Darwin

Collyer's fourth assertion is that "[a]s Charles Darwin admitted, there is no actual evidence of any species having developed into another species." This is a notorious creationist misquotation of Darwin, who in his lifetime grew tired of having to inform people that this was a misrepresentation of his views. Darwin at one point stated:
I am actually weary of telling people that I do not pretend to adduce direct evidence of one species changing into another, but that I believe that this view in the main is correct, because so many phenomena can be thus grouped together and explained. But it is generally of no use; I cannot make persons see this. I generally throw in their teeth the universally admitted theory of the undulation of light, -- neither the undulation nor the very existence of ether being proved, yet admitted because the view explains so much.
Modern evolutionary biology has progressed over the 150 years since Darwin's book was published. We have documented many examples of speciation in the field and the laboratory. Furthermore, examination of microfossils has provided us with a brilliant fossil record of gradual change in which we can state with confidence that fossil X is the direct ancestor of fossil Y. Not only has Collyer quote mined Darwin - an intellectually dishonest act - but he has simply not bothered to keep up with the palaeontological literature. It is impossible to take seriously anyone who resorts to quote mining Darwin in a desperate attempt to bolster the pseudoscience of special creationism.

Quote mining Darwin is one of the more tiresome creationist tactics. Apart from the intellectual dishonesty inherent in taking a person’s words out of context, it demonstrates the continued creationist belief that Darwin remains the supreme authority in evolutionary biology and that by finding errors in his works, they will be able to destroy evolutionary biology.

This betrays yet again a deeply flawed understanding not only of evolutionary biology but the epistemological basis of science itself. Science is inherently provisional, with things held subject to revision by new evidence. Darwin was wrong about a number of things, such as his theory of inheritance. However, two of his concepts – common descent and natural selection as a mechanism of evolutionary change – have withstood extensive testing and to date remain accepted by all other than a tiny minority of religiously motivated opponents. Evolutionary biology has advanced considerably since Darwin’s era, and to cite difficulties in evolution current 150 years ago makes as much sense as to dismiss general relativity, the modern theory of gravitation, because errors in Newton’s theory of gravitation.

If we return to the original matter – the alleged Darwin quotation – it does not take much research to realise that Collyer’s claim that Darwin had admitted there was no evidence of any species developing into another is false. The Talk Origins Quote Mine Project notes:

"Not one change of species into another is on record...we cannot prove that a single species has been changed." Charles Darwin, My Life & Letters

Charles Darwin never wrote any book by that title. It's commonly misquoted on many a creationist site. His son edited, after his father's death, a book called The life and letters of Charles Darwin. In which you can track down the second half of the "quote" above, but without any trace of the first half. [1]
This misquotation of Darwin could easily have been avoided by five minutes worth of research, but special creationists appear content to perpetuate misquotations that advance their agenda, rather than actually look things up. This is not research but propaganda.

Interestingly, it appears that during his lifetime, Darwin grew weary of answering this question. Mark Van de Wettering notes:

I found another interesting quotation while searching for "into another", quoted below...

I am actually weary of telling people that I do not pretend to adduce direct evidence of one species changing into another, but that I believe that this view in the main is correct, because so many phenomena can be thus grouped together and explained. But it is generally of no use; I cannot make persons see this. I generally throw in their teeth the universally admitted theory of the undulation of light,--neither the undulation nor the very existence of ether being proved, yet admitted because the view explains so much.

I find this interesting in two ways: because it freely admits that Darwin believed (although had no direct evidence for) the transmutation of species into another, and because of course it refers to the wave theory of light and the ether, whose existence was actually disproved in 1879 by the…Michelson Morley experiments (the letter above was written in 1861). [2]
Collyer's assertion is demonstrably false, but by far the bigger problem is his quote mining of Darwin. Given that it does not take much time to look up Darwin's works and see that he never made such a claim, either Collyer has quoted Darwin out of context, or he has blindly parroted special creationist claims without properly checking them. Neither option reflects well on his competence.

What about Collyer's assertion that we have no evidence for speciation? The simple answer is that he is wrong. Evidence for speciation is easily found in the scientific literature. A representative selection of speciation includes:

  • Homoploid hybrid speciation in plants has been documented [3] in eight cases:
  1. Helianthus anomalus
  2. Helianthus deserticola
  3. Helianthus paradoxus
  4. Iris nelsonii
  5. Peaonia emodi
  6. Peaonia species group
  7. Pinus densata
  8. Stephanomeria diagensis
  • Incipient speciation has been documented in yeast via divergent adaptation and antagonistic epistasis. This was shown [4] in an experimental population of the yeast Saccharomyces cerevisiae:
Unlike natural species, our experimental populations have an evolutionary history that is known with certainty. We can therefore conclude that divergent adaptation caused the reproductive isolation observed in this investigation. Experimental evolution of reproductive isolation has been studied in a few eukaryotes (mainly Drosophila) with mixed results. Previous research has focused mostly on prezygotic isolation, and we are aware of only a single study that reported successful evolution of postzygotic isolation by means of divergent selection. We present the most striking example of experimental evolution of postzygotic isolation observed in any organism, and the first for the fungal kingdom.

Although the isolation that evolved de novo in our short-term experiment is partial, it represents incipient speciation. Given more time, complete reproductive isolation is likely to evolve.
  • Incipient speciation in populations of Drosophila melanogaster via sexual isolation has been documented. [5] The authors note that “The results shed light on the population genetic processes underlying the formation of nascent species, as well as modes of speciation.”
  • Seehausen et al demonstrate [6] speciation within island populations of cichlid fish in Lake Victoria. The mechanism for this speciation is female preference for different male colouring, with differences in the light gradients in the lake being important in effecting speciation. As the authors note, this also explains why cichlid fish species collapsed during human-induced eutrophication.
  • The Rhagoletis apple fly provides an example of sympatric speciation occurring in the context of a shift from its native host to an introduced apple species. [7]
The fossil record provides powerful evidence of large-scale evolutionary change. As long ago as 1960, T. Neville George could say that:

There is no need to apologize any longer for the poverty of the fossil record. In some ways it has become almost unmanageably rich, and discovery is out-pacing integration: the growing number of species of Foraminifera that remain undescribed in the cabinets of the oil companies probably is of the order of thousands; and while most other organic groups are not so fully collected the ratio of added finds to palaeontologists studying them is constantly expanding. But what remains to be discovered is likely to be of less and less radical importance in revealing major novelties, more and more of detailed infilling of fossil series whose outlines are known. The main phyla, in so far as they are represented by fossils, now have a long and full history that is made three-dimensional by a repeatedly cladal phylogeny. The gaps are being closed not only by major annectant forms, the “missing links” that Darwin so deplored. . . . Together, the discovery of new fossil forms, the filling out of the details of bioserial change, the interpretation of biofacies, the adoption of new techniques both in fossil morphology and in fossil manipulation, and the establishment of a progressively refined timescale contribute to a present-day palaeontology offering the strongest support, the demonstrative “proof,” of the fact and the process of evolution in terms wholly concordant with the essence of Darwinian theory. [8]
As George's article has been in print for decades before Collyer's book, there is no excuse for alleging that there is no evidence of macroevolutionary change. This is characteristic of Collyer's arguments, which betray a complete ignorance of the professional evolutionary biology literature.

While the nature of allopatric speciation means that species-level transitions are not expected to be present in the fossil record, [9] the record of marine microfossils provides us with a splendid fine-grained example of evolutionary change. Cores taken of the deep sea bed can cover millions of year, allowing one to trace evolutionary history without breaks or gaps. Vertebrate palaeontologist Donald Prothero, recalling his own experience says:
Let us look at just one more classic example, probably the most extreme change in morphology ever documented in the fossil record. If you look at samples of microfossils from the middle Eocene (50 million years ago), you will find distinctive spongy ball-shaped radiolarians known as Lithocyclia ocellus. As you trace the spongy balls up through the sediments spanning millions of years, you see them gradually lose their spongy outer layers and develop into a small nucleus with four spongy arms (Lithocyclia aristotelis), then three arms (Lithocyclia angusta), and finally reduced to two arms forming a spindle-like shape (Cannartus tubarius). The Cannartus lineage then gradually develops a “waist” on the central sphere, then the arms get shorter and thicker, and finally, they split into two lineages: Cannartus peterssoni-Ommatartus hughesi, which evolves into a form with two arms with multiple spongy layers, and Ommatartus, which develops shorter arms and a fatter central sphere. If you look at the two extremes (a spongy sphere turning into a spindle-shaped shell with multiple caps), you could never imagine that they are closely related—yet I have looked at the slides from those cores and seen the gradual transition from one extreme to the other with my own eyes.

Evolutionary transformation in the cannartid-ommatartid lineage of radiolaria over the past 50 million years, from spongy balls to four- and then three-armed and finally two-armed bipolar structures, with further variations in the spongy caps later in their evolution. Taxa are as follows: 26, Lithocyclia ocellus; 27, Lithocyclia aristotelis; 28, Lithocyclia angusta; 30, Cannartus tubarius; 31, Cannartus violina; 32, Cannartus mammiferus; 33, Cannartus laticonus; 34, Cannartus petterssoni; 35, Ommatartus hughesi; 36, Ommatartus antepenultimus; 37, Ommatartus penultimus; 38, Ommatartus avitus; 39, Ommatartus tetrathalamus. (Modified from Haq and Boersma 1978)  [10]
The evidence is unarguable. Collyer is wrong. We have evidence of speciation in the field, in the laboratory and in the fossil record.

These barely exhausts the literature, but are enough to demonstrate that we do have evidence of speciation occurring via a number of well-documented mechanisms. Any creationist who asserts otherwise is uninformed and wrong. The fact that such speciation has been documented for some time before Collyer’s work again reflects badly on the depth and quality of his research. This is completely inexcusable, and also reflects poorly on the Testimony Magazine's science editors over the years for allowing this nonsense into the magazine, and making our community look like obscurantist fools and idiots.

1. http://www.talkorigi...-4.html#quote82
3. Rieseberg L.H. “Hybrid Origins of Plant Species” Annu. Rev. Ecol. Syst. 1997. 28:359–89
4. Dettman J.R. et al “Incipient speciation by divergent adaptation and antagonistic and antagonistic epistasis in yeast” Nature (2007) 447:585-588
5. Ching C, Takahashi A, Wu C “Incipient speciation by sexual isolation in Drosophila: Concurrent evolution at multiple loci” Proc. Natl. Acad. Sci. USA (2001) 98:6709-6713
6. Seehausen O et al “Speciation through sensory drive in cichlid fish” Nature (2008) 455:620-627
7. Bush G.L., Smith J.L. “The Genetics and Ecology of Sympatric Speciation: A Case Study” Res. Popul. Ecol. (1998) 40(2):175-187
8. George, T.N. "Fossils in Evolutionary Perspective," Science Progress, (1960) 48:1-3
10. Prothero D "Evolution: What the Fossils Say and Why it Matters" (2007: Columbia University Press) p 182-183