Evidence of common descent
Evidence of common descent of living organisms has been discovered by scientists researching in a variety of disciplines over many decades and has demonstrated common descent of all life on Earth developing from a last universal ancestor. This evidence constructs the theoretical framework on which evolutionary theory rests, demonstrates that evolution does occur, and is able to show the natural processes that led to the emergence of Earth's biodiversity. Additionally, this evidence supports the modern evolutionary synthesis—the current scientific theory that explains how and why life changes over time. Evolutionary biologists document evidence of common descent by making testable predictions, testing hypotheses, and developing theories that illustrate and describe its causes.
Comparison of the DNA genetic sequences of organisms has revealed that organisms that are phylogenetically close have a higher degree of DNA sequence similarity than organisms that are phylogenetically distant. Further evidence for common descent comes from genetic detritus such as pseudogenes, regions of DNA that are orthologous to a gene in a related organism, but are no longer active and appear to be undergoing a steady process of degeneration from cumulative mutations.
