Scientists have found multiple lines of evidence for evolution, not just one or two. These types of evidence are independent of each other, coming from sources as different as ancient fossils and modern genetics labs. Evidence also comes from comparing the anatomy of creatures living today. All creatures with four limbs (whether mammals, birds, or reptiles) have the same bone structure in each limb, pointing to their descent from a common ancestor. More evidence comes from biogeography. Isolated islands are missing common species found on the mainland, but are filled with many unique species that can be related by a common ancestor. Finally, evidence comes from embryonic development. As an embryo of a mammal grows, its heart develops through stages similar to fish, amphibians, and reptiles. God’s creation declares the history of life in many different ways. All these ways are pointing to a consistent picture of God creating through evolution.
For Darwin, both of these observations (that oceanic islands lacked terrestrial mammals, and that endemic species on islands were most similar to a species on the closest mainland) had the same explanation: his hypothesis that endemic, oceanic species were the modified descendants of a colonizing species from the nearest continent.
The Galápagos Islands were not a distinct “center of creation,” but a workshop for evolution in which an ancestral species made it to the yet uncolonized island and underwent a massive degree of speciation to adapt to the environment of the island. This is precisely what one would expect if the species of islands had arisen by evolution.
Stephen Matheson presents common descent by evolution as the best explanation for the universal pattern found in tetrapod limbs. He discusses initially the evolution and development of limbs in specifically vertebrate tetrapods. He looks at the question of origins and further digs into amazing fossil discoveries. He then gives evidence of evolution from fish to tetrapods by discussing the similarities in the anatomy, development, and genetic systems associated with this amazingly common pattern in vertebrate appendages.
This series features excerpts from biologist Sean Carroll’s book, Endless Forms Most Beautiful: The New Science of Evo Devo, a well-wrought account of how the field of evolutionary development biology, or Evo Devo, has shaped our understanding of how animals evolve, by studying their development.
Written by BioLogos Fellow of Biology Dennis Venema, this series of posts is intended as a basic introduction to the science of evolution for non-specialists.