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Showing posts from January, 2014

Pleisiomorphy and Synapomorphy: Evidence for evolution

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When it comes to evolution, many people don't understand what Darwin saw and why he believed that even humans had evolved. We have genetics now to solidify our evidence for evolution, but we also have a greater understanding for how similar to all our cousins we are.

In biology there is a Taxonomy which classifies families and groups of species. It separates others, but tells us how the lines are drawn. One important feature of evolution to understand is Pleisiomorphies and Synapomorphies. These are how things arose, who shares them and who doesn't.

Pleisiomorphy is an appendage which has a similar function, but arose from different lines of evolution.

Synapomorphy is an appendage which is similar in form and arose from common ancestors.

The importance in these is expressed in the photo above. The Bat, which is a mammal, has five digits on its upper appendages, it has evolved to have them at different lengths, and four of the five compose the wing portion of the bat, while th…