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Convergent Evolution Upends Honeyeaters' Taxonomy
grrlscientist writes in with a beautiful piece of science, beautifully explicated. The poignant bit is that the birds in question are all extinct. "Every once in awhile, I will read a scientific paper that astonishes and delights me so much that I can hardly wait to tell you all about it. Such is the situation with a newly published paper about the Hawai'ian Honeyeaters. In short, due to the remarkable power of convergent evolution, Hawai'ian Honeyeaters have thoroughly deceived taxonomists and ornithologists as to their true origin and identity for more than 200 years."
There have been debates over the taxonomy of odd creatures (with similarities to other known creatures) forever. Sometimes simple physical resemblence just doesn't really tell the tale. Of course, evolution producing similar looking/behaving birds is nothing new either (just look at how similar African parrots and South American parrots are to one another).
The really great debates come when zoologists get into trying to classify an animal that looks like (or behaves like) two DIFFERENT known creatures. One of my personal favorites is the Red Panda. The bottom of its body and claws look like a bear's (you can see it clearly in this picture) and it eats only bamboo, just like a Giant Panda. But the rest of it looks like a raccoon. This cute little furball finally had to be given its own unique family, because no one was quite sure where to put the little bastard. And it's still debatable if it truly deserves its own family.
SJW: Someone who has run out of real oppression, and has to fake it.
The answer is two-fold: money, and existing taxonomies are mostly correct.
Biologists have limited resources, so comprehensive reassessment of the entire tree of life based on genetic analysis is going to get done bit by bit over a long time, and we know we're pretty safe going with what we've got in the meantime.
And while enough genetic analysis has been done to confirm traditional taxonomy on quite a few species, it is only the cases where there is a disagreement that it makes the news. In all the other cases they agree, so traditional taxonomy is left intact.
There are a few dramatic cases like this one, though. There are a couple of species of lizard in the Yucatan that have an extra cervical vertebrae that turn out to have independently evolved that way (I prefer the term "independent evolution" rather than "convergent evolution", as the latter may confuse laypeople into thinking that distinct species have somehow become one.)
In those cases, genetic taxonomy wins, but they are always going to be in the minority.
Blasphemy is a human right. Blasphemophobia kills.
Ah, thanks for the kind invitation to join your discussions. i wish i had more time to do so, but alas, i have only a few hours per day of internet access, so i spend most of that time looking for papers to write about and answering emails as well as publishing my essays and images. but i will try to make more of an effort to comment here now and again!
My favorite example is the Naked Mole Rat. It lives in Africa in underground, and it is a kind of rat. However, as far as mammals go, it's very weird.
First of all, it's completely cold blooded. It cannot regulate its temperature at all. It's also blind and hairless. They have a queen that gives birth , and the others are workers in various castes, such as tunnel-maintainers, guards, or nurses.
So convergent evolution also happens in social structures, not just physiology.
Computers are useless. They can only give you answers.
-- Pablo Picasso