5.1 Evidence for Evolution

A fossil is the preserved remain or trace of a past organism - The totality of all fossils is called the fossil record Law of Fossil Succession: The fossil record shows that changes have occurred in organism and these changes have occurred in a consistent sequence of development (the law of fossil succession) Example: Ferns always appear before flowering plants Transitional Fossils: Transitional fossils represent intermediary forms within the evolution of a genus and demonstrate species connections. Example: The archaeopteryx links the evolution of birds (wings and feathers) to dinosaurs (jaws and claws).

Is when you breed animals with desired characteristics (it is a form of artificial selection). Examples of this Draft horses (power and Race horses (speed) Dog breeds Cows with larger pelvis.

Closely relates species share a greater degree of similarity in their DNA and protein sequence (due to a common ancestor). If a particular gene has a stable mutation rate, the time of evolutionary divergence can be estimated (molecular clock)

Some species show presence of functionless or reduced remnants of organs that were once present in ancestors. ie. Whales (pelvic bone (ancestors were terrestrial).

Homologous Structures are anatomical features that share a common basic structure despite having distinct functions. Rapid diversification of an anatomical feature is a result of adaptive radiation (organisms adapt to different niches) Closely related species demonstrate greater homology. Pentadactyl limb- Human arm, horse leg, whale arm, turtle arm, frog arm, bird arm.

Comparative embryonic development in animals demonstrates similarities that suggest a common evolutionary pathway. All terrestrial animals have non-functioning gills slits. Many vertebrates have a primitive tail in early stages.

Biogeography is the distribution of species across an area . Related species will usually be found in close proximity. Monotremes are exclusive to Australia/ New Guinea. Exceptions may be explained via continental drift.