Here’s an interesting story from the Discovery Channel.
“Yes,” I know you’re thinking, “next question?”.
But wait, the story takes a different approach.
Plants and animals may occupy distinct branches on the tree of life, but they could be more alike than we think.
In fact, green plants and animals enjoy a relatively close evolutionary relationship that has been obscured by a narrow focus on DNA sequences to find relatedness, says biologist John Stiller of East Carolina University.
Plants, fungi and animals are all in a group called the eukaryotes — distinguished by their advanced cellular machinery. But some eukaryotes, most notably the fungi, have long been considered more closely related to animals than plants are.
Stiller’s theory suggests organisms such as fungi should be given a demotion — placed further from animals on the tree — while green plants should get a leg up.
Another attribute shared by plants and animals, according to Stiller, is the way the genetic material RNA operates in both groups. In both plants and animals, RNA acts as an intermediary between DNA and the protein it codes for. The enzymes that put RNA to work in a cell are similar in plants and animals, but not present in fungi or other organisms, he said.
It is, of course, utterly inconceivable that the common ancestor to all three groups had this trait which was then lost in fungi. Because fungi are, of course, not a derived group that has been evolving for exactly the same amount of time as plants and animals by definition. Oh no.
Maybe the paper makes a good argument. Maybe plants and animals are sister taxa to the exclusion of fungi. But one thing’s for sure — no one’s getting “demoted” one way or another because this idea of rank
was should have been abandoned 150 years ago.
See Sex, Genes & Evolution for more insights on the actual hypothesis, which should not be judged on the basis of how it was reported in the press.