Evidence for Evolution Biogeography What is it Biogeography

Evidence for Evolution

Biogeography- What is it? • Biogeography is the study of where species are found geographically. • Some closely related species have different adaptations to nearby environments. • Some unrelated species have similar adaptations to similar environments that are found far apart.

How is it evidence? • Natural selection explains the diversity of life we see. • Species migrated to new environments and then became adapted to them.

Example: Galapagos Finches • 14 species of finches that came from one ancestor and differ in the size and shape of their beaks.

Anatomy and Embryology • Anatomy is the study of the body structures of organisms. • Embryology is the study of how organisms develop. • Similar structures can be seen in different species for different reasons.

Homologous Structures • Homologous structures are anatomical structures that occur in different species that were inherited from a common ancestor. • Example: Forelimbs in humans, penguins, alligators, and bats

Homologous Structures

Analogous Structures • Analogous structures are anatomical structures that have related functions, but were not inherited from a common ancestor. • Ex: Moth wings, bird wings, bat wings

Analogous Structures

Vestigial Structures • Vestigial structures do not serve a function in an animal but resemble a functional structure in a related organism. • Example: Human tailbone has no function but resembles the tail found in many other mammals.

Development • Evidence for evolution can be seen in the development of vertebrates.

DNA Evidence • Scientists compare DNA sequences of different species. • The more alike the sequences are, the more closely related the species are.

Phylogeny • Phylogeny = relationships by ancestry among groups of organisms • Scientists construct diagrams called phylogenetic trees to show relationships.

Phylogeny • Trunk = past species that was ancestor • Branch = separate populations • The closer the branches, the closer related the organisms.