Fossil Record • Compare the fossils of older rock layers to newer layers to piece together evolutionary history. • Evolution of the horse • What does the fossil record tell us?
Biogeography • Species living on different continents descended from different ancestors. • If similar ecological conditions, different animals evolve with features in common. • Placentals of N. America • Marsupials of Australia
Biogeography • Sabertooth cat (North America) • Sabertooth marsupial (South America) • http://www.fieldmuseum.org/evolvingplanet/tertiary_16.asp
1. How do homologous structures show divergent evolution?2. How do analogous structures show convergent evolution?
Vestigial Structure • Nas no function in present-day organism but was useful to an ancestor.
Embryology • What do all vertebrate embryos have in common? • How do these vertebrate embryos change during development?
GENETIC COMPARISON • DNA strands are separated, then placed with a strand of another species. • How can this determine common ancestry?
ADAPTATION Structures, behaviors and internal processes that better suited for survival. Examples: Defense Warning coloration Camouflage
Adaptation • Mimicry • Similar warning colors for different species. • bees & yellowjackets • Species lacking toxic chemicals has adopted the warning coloration. • Monarch & Viceroy butterflies