Espalier
September 21, 2010 at 7:35 pm 1 comment
Time Tree is a new search utility for those interested in evolutionary divergence times between organisms in the published literature. Time Tree uses a hierarchical system to identify all published molecular time estimates on the divergence of the selected taxa and presents the results in a tabular format.
According to PennState’s press release:
“Timetrees are having broad impact in biology and in other fields such as geology, and even in human health, where researchers need to track the evolution and spread of disease-causing organisms,” said Hedges. At the other end of the timescale, astrobiologists, who study the origin and development of life in the universe, need to know which organisms were responsible for changes in the chemistry of rocks on Earth that are billions of years old. A timetree could rule out species that had not yet evolved at the time the rock formed, while implicating other species that have deep evolutionary branches. “The variety of uses of a timetree really drives home its power as an interdisciplinary tool,” said Hedges, himself an astrobiologist.
Of course when I found the app I immediately ran a search to find out when Homo sapiens and Canis lupus familiaris first diverged:
According to Time Tree, the species who would become man and dog first began to diverge about 100 million years ago. What Time Tree doesn’t tell is is that, in a rare and wonderful bit of evolutionary husbandry, somewhere between 12,000 and 135,000 years ago these two species would be espaliered together again.









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Rob McMillin | September 22, 2010 at 1:03 pm
Aren’t all of these sorts of things based on the idea of constant rates of mutation, based on transcription error rates and the like? I wonder if they take into account the possibility that more or less ionizing radiation might be present at the earth’s surface at any given point in time, or at a particular place (e.g. imagine a place where mildly radioactive isotopes are in greater concentration than elsewhere).