Archetype

Nineteenth century figure found to be wrong about something, kind of

I have Google Alerts set for the term “cladistics” so I will receive a feed every time Google indexes that word. Now, in the last couple of days those feeds have catch a story circulating in the news media regarding a recently published study looking at the appendix from a comparative and phylogenetic perspective, pretty cool if you ask me.

I can only access the abstract of the original publication unfortunately, but it does seems to be a well done and thorough study. The problem is the way the report gets increasingly hyped by the news media. I first got this: Evolution of the appendix: A biological ‘remnant’ no more. OK, that’s not bad. I then got this: Appendix redux. Yeah, sure, succinct and clever. But today I got this: Darwin wrongly called the appendix a biological ‘remnant’, say researchers:

Charles Darwin was wrong when he theorized that the appendix in humans and other primates was the evolutionary remains of a larger structure, called a cecum, which was used by now-extinct ancestors for digesting food, according to research collaborators from three U.S. institutions.

Here we go again. There is nothing better to sell a story than to bash a long dead historical figure in the very year devoted to celebrate his legacy.

Some precious quotes:

“Darwin simply didn’t have access to the information we have. If Darwin had been aware of the species that have an appendix attached to a large cecum, and if he had known about the widespread nature of the appendix, he probably would not have thought of the appendix as a vestige of evolution,” said Parker.

and

The study report further states that Darwin was not aware of the fact that appendicitis [...] is not due to a faulty appendix, but rather due to cultural changes associated with industrialized society and improved sanitation. [...] The researcher added that that notion wasn’t proposed until the early 1900’s, and “we didn’t really have a good understanding of that principle until the mid 1980’s.”

This last quote completely destroys my admiration for Darwin. I mean, was it all that difficult for him to anticipate scientific findings 100 years into the future? And, why didn’t he embark into time travel instead of wasting his time traveling to the Galapagos islands?

Darwin on rudiments

In the Origin of Species¹. Darwin devotes an entire section in Chapter XIII (the best chapter mind you) entitled Rudimentary, atrophied, or aborted organs in which he discusses how an evolutionary perspective provides the best explanation for the common occurrence of organs that seem not have any apparent function, organs that shouldn’t be there if organisms were independently designed for a specific purpose. They are simply anatomical leftovers from a more glorious past. Darwin even draws an analogy with spelling and pronunciation in comparative linguistics: words may retain letters that are no longer useful in pronunciation. For example, the word for ant in Latin is formica, from which we got formiga in Portuguese and hormiga in Spanish. The latter retained a vestigial h even thought it is mute, and so it has no function in pronunciation.

Now, Darwin does discuss that rudimentary does not necessary means functionless:

An organ serving for two purposes, may become rudimentary or utterly aborted for one, even the more important purpose; and remain perfectly efficient for the other. [pag. 451]

and,

[A]n organ may become rudimentary for its proper purpose, and be used for a distinct object. [pag. 452]

Some of Darwin’s examples for particular evolutionary processes will surely turn out to mistakes, but his clear insight into how evolutionary theory explains the facts of comparative anatomy will always be impeccable. By the way, the new study on the appendix shows that once morphology is done properly, everything falls neatly into place.

Oh, and while we are at historical figure bashing, let me point out that Aristotle did not know that that DNA is the main hereditary material of living systems. What an idiot.

References

Tags: Charles Darwin, Rudimentary organs

1 Comment to Nineteenth century figure found to be wrong about something, kind of

1

Kai
August 21, 2009

Laughing at that last statement on Aristotle.

Yes, this sort of thing again. On the other hand, it gives you an opportunity to quote On the Origin at length, always a good thing.