WIKIMEDIA, GRINGERScientists have created a new tree of life showing the relationships among all known living things, which taxonomists typically classify into one of three domains: eukaryotes, bacteria, and archaea. One of
WIKIMEDIA, GRINGERScientists have created a new tree of life showing the relationships among all known living things, which taxonomists typically classify into one of three domains: eukaryotes, bacteria, and archaea. One of this new tree’s largest branches consists of bacteria that are essentially new to science, according to a study published today (April 11) in Nature Microbiology.
“The significant feature [of the tree] is so many of the major lineages have no isolated representatives”—that is, that none of their species have been cultured individually in the laboratory, said Jillian Banfield of the University of California, Berkeley, who led the work. “Much of the world around us is populated by organisms we know nothing about,” she added.
“It’s a great step forward,” said the Florida Museum of Natural History’s Doug Soltis, who was not involved in the work. Soltis led the construction of an open-access phylogeny, published last year, which stitched existing trees together into one including 2.3 million species, of which few were microbial. “It’s exactly what you want to see if you’re interested in the tree of life, because what we produced was just... a starting point, and the bacteria, in particular, are poorly represented in that tree,” he told The Scientist.
The tree of life has developed “in jumps and fits,” explained University of California, Davis, evolutionary biologist Jonathan Eisen, who was not involved in the work but who commented on the manuscript before it was submitted and has previously collaborated with Banfield. The tree’s iterations have included the eukaryote-prokaryote dichotomy, the “five kingdoms” system, and the three-domain system, outlined by microbiologist Carl Woese in a landmark 1987 pape