Canadian scientists have identified microscopic creatures that are so unlike anything seen before, they had to create an entirely new branch on the evolutionary tree of life to slot them in.
A new paper published [November 14] in Nature offers the first genetic analysis of hemimastigotes—a rare and poorly understood group of single-celled microorganisms. Biologists have known about these wee beasties for well over a century, but only now can hemimastigotes be officially slotted into the evolutionary tree of life, a process more formally known as phylogeny. And by doing so, scientists have stumbled upon a completely new branch on the tree of life.
Hemimastigotes cannot be classified as animal, plant, fungus, or bacteria. But they’re eukaryotes, having complex cells and a clearly defined nucleus. Eukaryotes that can’t be slotted into these conventional groupings are called protists—a kind of grab-bag grouping of sometimes unclassifiable eukaryotes.
“It was clear from our analyses that hemimastigotes didn’t belong to any known kingdom-level group, or even to a known ‘super-group’ of several kingdoms together, like the one that includes both animals and fungi,” said Simpson. “This one little collection of organisms is a whole new group at that level, all on its own.”
Read full, original post: Bizarre Microbes Represent a Major New Branch on the Evolutionary Family Tree