Monday, November 3, 2008

Linear Evolution: McCain and Obama

A common theme of this blog is to share cases of "linear evolutionary thinking". These are instances, usually graphics, that illustrate the common conception of evolution as a line of progress, from worst to best. Evolution actually occurs by branching processes. We could pull out a line of evolution from the tree, but that line by necessity has an arbitrary endpoint, often humans or a human-like feature. And living species or their traits cannot necessarily be equated with ancestral forms.

Ostracod eye evolution has been depicted as a straight line from simple to compound eye, illustrated here. Textbooks use such diagrams (see also this), and these diagrams can impact the way people think about evolution.

Here is another variation on the human march of progress, which shows Barack Obama as the more advanced political candidate, compared to John McCain.

Thanks to my brother for sending this to me.


Eric Heupel said...

Just catching up on all my blog reading and postings and this one jumped out at me! Hilarious.

Anonymous said...

Some species have a remarkable power of crossing with other species; other species of the same genus have a remarkable power of impressing their likeness on their hybrid offspring. -- Charles Darwin.

Anonymous said...

I think these authors are right, who maintain that the Africans has a prepotent power over the Europens, so that both the meta mulatto and the para mulatto more resemble the Africans than the Europeans; but that the prepotency runs more strongly in the male Africans than in the female Africans, so that the meta mulatto, which is the offspring of the male Africans and female Europeans, is more like a Africans, than is the para mulatto, which is the offspring of the female Africans and male Europeans.