10.4 Evidence of Evolution

biogeography
study of the distribution of organisms around the world
Embryology
similarities in development of embryos suggest a distant, common ancestor
homologous structures
features that are similar in structure in different organisms and have different functions.
analogous structures
Structures that perform a similar function in different organisms, but are not similar in origin.
analogous structure
Is NOT evidence of a common ancestor
Vestigial Structure
Remnant of an organ or structure that had a function in an early ancestor. Ex: Wings of ostriches, appendix in humans
Vestigial Structure
Did not get smaller in one individual organism. It took MANY generations for the organs to shrink.
Vestigial Structure
MOST IMPORTANT example of demonstrating how evolution works.
Vestigial Structure
Underdeveloped or unused features
homologous structure
Examples are the wing of a bat, and hand of a human
analogous structure
Wing of a bird and wing of an insect.
Embryology
The similar features of embryos in very different organisms suggest evolution from a distant common ancestor.
Why fossils are important
Their age, location and what the environment was like when the organism was alive.
Fossils
Fossil organisms in the bottom older layers were more primitive than those in the upper newer layers.
Fossils
supported Darwins concept of descent with modification
Fossils
Scientists can make distinct correlations between ancient organisms and modern day species.