This theory is a cornerstone of modern evolutionary biology, and it is supported by a vast amount of evidence from various fields, including:
* Fossil record: Fossils show a clear progression of life forms over time, with simpler organisms appearing earlier and more complex ones appearing later.
* Comparative anatomy: The similarities in the anatomy of different organisms, such as the bones in the limbs of mammals, birds, and reptiles, suggest that they share a common ancestor.
* Molecular biology: The similarities in the DNA and protein sequences of different organisms provide strong evidence for common ancestry.
* Biogeography: The distribution of species across the globe is consistent with the idea that they evolved from ancestors that were geographically separated.
While the theory of common descent is widely accepted by scientists, it is important to note that it does not specify the exact mechanism of evolution. The mechanism most commonly associated with common descent is natural selection, but other mechanisms like genetic drift and mutation can also play a role.
