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