Wednesday, March 13, 2013

Science reporting on evolution still bad

Ran across this article last night.

The article is about evidence that dust mites who are currently parasites may be evolving into a free living organisms. The reason it is talked about as reverse evolution is because dust mites used to be free living organisms before they became parasitic. The article is written as if the author is presenting a startling new find that is over turning scientists previous belief that evolution does not work in reverse. The idea that evolution is working towards some sort of goal is inaccurate

The main problem here is that the author seems to confuse the evolutionary process which is basically genetic variances, with the taxonomical or behavioral changes that are sometimes produced. That is, in order for evolution to reverse the species would have to follow the exact same genetic changes one step back at at time, considering all of the possible variances it is easy to imagine that, while this is technically possible, it is not very likely. This is actually a concept called Dollo's law of irreversibility.

However, it is entirely possible for a species to follow an evolutionary pathway that leads something very similar behavior or taxonomy to an earlier or separate species. It's called Convergent evolution and we have know about it for a long time because there are already examples of it everywhere. For instance, most birds, many insects, and bats all use wings to achieve flight but the genetics that created those wings are each completely different, and we can see this in taxonomical differences in these wings. Another good example is whales who, despite their earlier ancestors moving out of the water, moved back into it. They did not stop being mammals but they did evolve many traits to deal with aquatic living that are very similar to fish. Again whales did not go backwards, they did not use the same genes as fish, they evolved a new set of genes that created similar taxonomy.

There is nothing to suggest that dust mites have followed some path backwards to an earlier form, but why should the facts get in the way of science reporters making up attention grabbing headlines on their articles to increase their readers? People will know what they really mean right? It's not like there are systematic misunderstandings of evolution in this country or anything.

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