*Say, we natural scientists really ought to be doing something to commemorate the 200th anniversary of Darwin’s birth, seeing as how evolution is the cornerstone of the biological sciences and all.
By a striking coincidence, we’ve recently discovered a phenomenally well-preserved early primate fossil, that appears to represent a critical point of divergence between monkeys and lemurs.
Unfortunately, no one outside the scientific community gives a rat’s ass about the point of divergence between monkeys and lemurs.
Perhaps we could use this opportunity to educate the public about the significance of the find, while elucidating the subtle connections between early primates and modern humanity, and the evolutionary forces that have shaped us all.
Or we could just lie our asses off about how this fossil is the missing link that proves Darwin’s theory of evolution, and hope that no one calls us on it.
What do you think we should do, Sir David Attenborough?*
Think about it-- if it’s a common ancestor of lemurs and monkeys, then it has to be a common ancestor of humans and chimps. My understanding is that it’s probably a lemur type animal, and (as is true of most fossils) might not be the ancestor of any living creature today.
The specimen is not a “recent discovery”. It was originally discovered back in 1983 by a private collector. Because it lies in a shale deposit, there are essentially two “tablets” containing the fossil. The left side of the skeleton is on what the authors call “Plate B”, and was only partially complete. This side of the fossil was earlier described and classified as Proncycticebus neglectus, and later placed in a separate genus, Godinotia. The paper published yesterday re-evaluates this based on the recent acquisition of the right side of the fossil, and re-classifies the specimen as Darwinus masillae.
By ICZN (International Code of Zoological Nomenclature) rules, that name may not be recognized as valid. They have strict rules for publishing valid names, and as it stands right now, web-only publications are not considered valid for nomenclature purposes. That will likely change in the future, however.
The phylogenetic analysis appears to be somewhat cursory. Further analysis will be required to sort out its proper place among primates.
In essence, then, it’s a bit early to tell whether this specimen changes anything, much less everything. In fairness to the authors, however, they conclude the paper with the following:
The grand pronouncements on how this specimen “proves evolution” or “changes everything” about primate evolution were made by the museum staff (and perhaps magnified by the press), not the authors (at least, not in the paper; what they may have said in public may well differ, and doesn’t necessarily relate to the actual scientific impact of the critter).
Also, based on the cladogram the authors included, Darwinus is more closely related to Haplorhini than to Strepsirhini (which, amusingly, the authors misspelled on their cladogram as “Sterpsirrhini”), so it wouldn’t actually be a common ancestor of lemurs and monkeys at all.
Whether it’s actually another nail in the coffin or not is immaterial; the coffin is all nails by now, but the creationists are all accomplished fakirs.
Yep. And as others have noted, the concept of a “missing link” is sloppy journalism, not good science. Everything is a “missing link”. Even the term “transitional species” is problematic. “Transitional” only makes sense in looking backwards, but it implies that there was some sort of direction that the species was headed in. We all know, of course, that evolution just happens-- it doesn’t proceed in any particular direction. One might argue that the term makes sense in the context of Punctuated Equilibrium if one finds a specimen that was “punctuating” two different “equilibria”, but again it only makes sense after the fact.
These days, “transitional” refers more to morphology than to a particular species. “Transitional species” only makes sense if it has been demonstrated that this species was, in fact, intermediate between a particular set of parent and daughter species. Transitional forms, however, are useful in tracking the evolutionary sequence of particular traits. Any given species itself could well have been an evolutionary dead-end, but it can represent a particular “grade” of morphology, meaning that closely related forms (which may have been actual ancestors to a given group) were likely similar.
Of course, the whole idea of transitional forms is only necessary and/or relevant because of the “snapshot” quality of the fossil record. If every species that ever lived were recoverable, even the idea of transitions would be largely meaningless, since we could then trace unbroken sequences for any given lineage.
I believe I’m going to have to take this back. The more I read about this whole thing, the more seedy it seems. Hurum, one of the main authors, and the one who acquired the specimen, seems to be shilling for The History Channel for their stupid “this changes everything” special on this fossil. So despite the relatively conservative conclusion of the paper, he’s basically undermining everything that could be scientifically fascinating about this specimen in public.
And the phylogenetic analysis is more than cursory…it’s downright shoddy.
This fossil is not earthshaking, it doesn’t change much of anything, and it has been lying in a laboratory drawer for twenty years. It’s pretty much a non-event to anthropologists, since it really only lends more support to the already prevailing notions that (a) the primates are all interrelated, and (b) that some creature existed in the early Eocene which combines primitive anthropoid and prosimian (lemuroid) traits. Its existence was already postulated on entirely reasonable grounds. Fossils of animals not terribly different, and almost contemporaneous with “Ida”, have long been known–and even described in Time LIfe books aimed at the general populace.
While conceding that the specimen is remarkable for its state of preservation, I can’t allay the feeling that this is another HIstory Channel blitz, much ado about nothing, and that it’s being presented chiefly because they can’t find or afford any better content to squeeze in between the commercials for term life insurance, the Scooter Store, and Mega Health Insurance.
