Common descent

From EvoWiki

Common descent is the idea that two populations or species share a common ancestral species, and are both descended from that ancestor by normal processes of replication. This is a fairly commonplace notion.

The theory of common descent states that all species (on Earth, at least) share common ancestors, back to a single common ancestor of all life. This is a fairly profound notion.

The mechanisms that produce diversity from common ancestors are those of the Theory of Evolution. The word evolution is often confused with common descent.

Evidence for common descent

One of the most compelling forms of evidence is the 'molecular fingerprint'. This is a unique combination of molecules found in a specific cell. If cells between species have matching molecular fingerprints, then the cells very likely share a common ancestor cell. Using this method, scientists from the European Molecular Biology Laboratory provided concrete evidence in 2004 that the human eye evolved from cells that were initially located in the brain.