Re-imagining a Tree of Life
A Tree of Life from the Norse Sagas (credit: Wiki-commons)
In one form or another, a Tree of Life has been symbolic in global cultures and religious traditions. From the ancient Chinese, Egyptians, and Norse, to the Celts, Jews, Christians, and Buddhists, even the Aztecs and Mayans, all these 'trees' tell an origin story. The tree can represent a life source; a physical or symbolic form that connects all lives; future regeneration or rebirth; or the life and death biological cycle itself. Common features often include supernatural guardians protecting the tree or longevity granted to people who eat its fruit. Traditional and modern forms can be simple or elaborate and they are often very beautiful considering the real or imagined inspiration.
Mexico Tree of Life ca.500 CE (credit: Jordan Anderson) Modern Celtic Tree of Life carved oak (credit: Knight Woodcraft)
The biological sciences of evolution, speciation, and genetics are no exception to creating a 'tree of life' but its complicated. Compiling all living organisms and correctly illustrating their known relationships has been like searching for the Holy Grail. It is a daunting task considering that more than two million species are currently known and new species are discovered every year. Arranging them in an evolutionary correct representation has been another gigantic challenge.
Investigators at the University of Michigan and their associates have published a new version in the Proceedings of the National Academy of Sciences (PNAS).Their study applied an efficient and automated process to combine existing 'trees' into a representative evolutionary assemblage. Their digital version is readily updated as additional species are identified and genetic (DNA) data is available. The data visualization and related open-source information is available to download and their complete publication is available here.
New Tree of Life Visualization (credit: PNAS)
A video explains the utility of the new evolutionary 'tree of life' construct. It is a fitting companion to traditional depictions. Do you see yourself sitting anywhere on this new tree? WHB