the roughly 2.3
million named species of animals, plants, fungi and microbes.
The draft took
three years to complete and was accomplished by combining
more than 450
existing trees. Image credit: Stephen Smith
(September 19, 2015) A
first draft of the "tree of life" for the roughly 2.3 million named
species of animals, plants, fungi and microbes has been released, and two
University of Michigan biologists played a key role in its creation.
A collaborative effort among 11 institutions, the tree
depicts the relationships among living things as they diverged from one another
over time, tracing back to the beginning of life on Earth more than 3.5 billion
years ago.
Tens of thousands of smaller trees have been published over
the years for select branches of the tree of life—some containing upwards of
100,000 species—but this is the first time those results have been combined
into a single tree that encompasses all of life. The end result is a digital
resource that is available free online for anyone to use or edit, much like a
"Wikipedia" for evolutionary trees.
Understanding how the millions of species on Earth are
related to one another helps scientists discover new drugs, increase crop and
livestock yields, and trace the origins and spread of infectious diseases such
as HIV, Ebola and influenza.
"This is the first real attempt to connect the dots and
put it all together," said principal investigator Karen Cranston of Duke
University. "Think of it as Version 1.0." A paper summarizing the
findings was published online in Proceedings of the National Academy of
Sciences on Sept. 18.
U-M evolutionary biologist Stephen Smith heads the group
that tackled the nitty-gritty details of piecing together all the existing
branches, stems and twigs of life's tree into a single diagram. Cody Hinchliff,
formerly a postdoctoral researcher in Smith's lab who is now at the University
of Idaho, did much of the heavy lifting on the project and shares first-author
credits with Smith on the PNAS paper.