Evidence of Evolution
Evidence: information from
observations and experiments
Fossil Evidence
• Locations of many fossils are evidence that
two species with a common ancestor can
develop differently in different locations.
• Example: Scientists have compared modern
algae and plants to fossil algae. All share a
common ancestor.
Biological Evidence
Similarities in Structure
• Vestigial organs= structures that were used in
ancestors but are unused in modern species.
Example: appendix in humans, hind limb
bones in whales.
• Similar bones in the flipper of a manatee, wing
of bat, and leg of gecko.
More biological evidence…
Similarities in development
• Animals of very different species are very similar
as embryos. It isn’t until later in development
that different characteristics develop. Genes
that control this similarity were inherited from a
common ancestor.
Genetic Evidence
• Scientists can tell how closely related
organisms are by comparing their DNA.
• Example: Almost all genes found in mice are
found in humans.
• Similar DNA in very different species is strong
evidence of common ancestors.