GreenTracker| A Brandeis biochemist reports the first comprehensive, quantitative test of Charles Darwin’s theory of evolution. In his book “On the Origin of the Species” Darwin proposed that “all the organic beings which have ever lived on this earth have descended from some one primordial form.”
If you believe that orchids are your cousins, you’re not a plant-loving wacko.
Darwin’s theory of Universal Common Ancestry (UCA) encompasses both a single evolutionary path and also a “tree of life” theory in which widespread, rapid gene transfer creates a more web-like proliferation of life.
Scientists have previously embraced the probability that vertabraed-creatures have evolved from a common ancestry.
Theobald is the first to formally test Darwin’s theory across all three domains of life, confirming that trees and humans are related. The three domains include diverse life forms such as the Eukarya (organisms, including humans, yeast, and plants, whose cells have a DNA-containing nucleus) as well as Bacteria and Archaea (two distinct groups of unicellular microorganisms whose DNA floats around in the cell instead of in a nucleus).
Harnessing powerful computational tools and applying Bayesian statistics, Theobald found that the evidence overwhelmingly supports Universal Common Ancestry, regardless of horizontal gene transfer or multiple origins of life. Biochemist Douglas Theobald said UCA is millions of times more probable than any theory of multiple independent ancestries.
. . it doesn’t really matter. “Let’s say life originated independently multiple times, which UCA allows is possible,” said Theobald. “If so, the theory holds that a bottleneck occurred in evolution, with descendants of only one of the independent origins surviving until the present. Alternatively, separate populations could have merged, by exchanging enough genes over time to become a single species that eventually was ancestral to us all. Either way, all of life would still be genetically related.” via Science Daily
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