Biology Unit 2

the scientific study of the geographical distribution of organisms of both living species and fossils.

the natural arrangement of various forms of animals and plants in different regions.

a structure with a common evolutionary origin that may serve different functions in modern species. Ex bat wings and human arm

similar structure with the same common ancestor - different function

The homologous features he observed could be explained by evolution Closely related species have homologous features because they shared the same common ancestor Overtime original structure were modified as each species evolved

-a structure that performs the same function as another but it is not similar in origin or anatomical structure. Ex. bird and insect wings. Birds and insects are only distantly related and have evolved these features quite independently of each other. Ex. octopus and human eyes

Homologous structure vs analogous structure -similiar structure -differing structure -differing function -similiar function -from a common ancestor -not from common ancestor

-features that no longer serve the function they do in similar species

-some large snakes and whales have vestigial hip bones, which are homologous to the hip bones that support the hind limbs of other vertebrates.

1.the upland goose and frigate bird have webbed feet but never enter the water 2.goosebumps in humans - raising our hair does nothing to keep us warm or make us look larger, theres no purpose