Scientists have released the first draft of the "tree of life" for about 2.3 million named species of plants, animals, microbes and fungi on the planet.
A collaborative effort of researchers from eleven institutions, the tree provides more details about the relationship between species and about evolution as living things diverge from one another over time.
The tree, which was described in a study published in the Proceedings of the National Academy of Sciences on Sept. 18, traces back to the beginning of life on our planet over 3.5 billion years ago.
"With bigger and more resolved trees we can answer evolutionary questions on scales not previously possible," the Open Tree of Life blog reads. "Sparse lineage sampling and hence unaccounted for diversity has previously been a hindrance when analyzing evolutionary trends that span the tree of life, but the time is approaching (or might be here already!) where the size of the phylogenies will not be the limiting factor in studying broad scale evolutionary questions."
Evolutionary trees are not just meant to determine how animals are closely related to other species. Knowing how the different species on Earth are related to each other can help scientists increase livestock and crop yields, discover new drugs, and trace the origin and transmission of infectious diseases including those that remain incurable such as HIV and Ebola.
"The tree provides a compelling starting point for community contribution," the researchers wrote. "This comprehensive tree will fuel fundamental research on the nature of biological diversity, ultimately providing up-to-date phylogenies for downstream applications in comparative biology, ecology, conservation biology, climate change, agriculture, and genomics."
Thousands of trees have already been published earlier for select branches of the tree of life. Some of these maps even contain more than 100,000 species. The new tree of life though is the first time that researchers used these earlier trees and combined them into a single tree that covers all life.
The researchers pieced the new tree of life by using thousands of smaller trees that have already been published online. They merged these trees together to form the gigantic supertree that comprises all named species.
The initial draft of this tree is based on about 500 smaller trees from studies published earlier and can now be viewed or downloaded online. The researchers said that the tree of life is just the first version and is not yet finished.
"As important as showing what we do know about relationships, this first tree of life is also important in revealing what we don't know," said Douglas Soltis, from the University of Florida, adding that 25 years ago, people though that the goal of huge trees was not doable. "The Open Tree of Life is an important starting point that other investigators can now refine and improve for decades to come."
