Biological evidence and the Fossil record

January 12, 2023

fossil

the preserved remains or evidence of a species

homologous structure

a similar trait found in 2 different species that is the result of having a common ancestor

transitional forms

fossils that show intermediate states between an ancestral species and its evolutionary descendants

vestigial structure

a structure that has evolved to have no function in an organism

Homologous, ancestral, vestigial

comparative anatomy includes:

analogous structure

are structures that are similar because they are advantageous, not because they are related.

DNA and cells

molecular homologies are similarities in the molecular structures that make up organisms, which include:

molecular homologies

are similarities in the molecular structures that make up organisms

common ancestor

molecular homologies are due to descent from a:

Miller-Urey experiments

Gave molecular evidence for evolution by showing that the building blocks of life could form from nonliving matter

transitional forms

are fossils that show intermediate states between an ancestral species and its evolutionary decendants

gradualism and punctuated equilibrium

Perspectives of evolution

gradualism

evolution occurs through slow and steady changes over time

punctuated equilibrium

little or no change for a long time then brief periods of rapid change.