Evolution Objectives: 12.0 Describe protective adaptations of animals, including mimicry, camouflage, beak type, migration, and hibernation. 12.1 Identifying ways in which the theory of evolution explains the nature and diversity of organisms 12.2 Describing natural selection, survival of the fittest, geographic isolation, and fossil record

Lamarck’s Theory of Evolution Proposed that selective use or disuse of organs caused organisms to acquire or lose certain traits during their lifetime. This would lead to those traits being passed on (or not) to their offspring. EX: You work out and have huge biceps, so your offspring will have huge biceps. WRONG!!!! (Why?) Adam and Eve – ribs?

Thomas Malthus Reasoned that if human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone. What are some “forces” that influence (decrease) human population? Answer: war, famine, disease Darwin realized this applied even more strongly with plants and animals! (Why?)

Natural Selection (Darwin) We have already agreed that artificial selection happens, so why couldn’t natural selection occur on a slower scale? Struggle for existence - competition among members of a population for resources “hiding” from predators

Natural Selection Survival of the fittest Descent with modification Those who survive long enough to produce offspring and pass on their traits Adaptation – any inherited characteristic that increases an organism’s chance of survival Descent with modification Over long periods of time, natural selection produces organisms that look different from their ancestors Carried to its fullest extreme: common descent says we all have one common ancestor.

Evidence of Evolution Geographic distribution- species that are better adapted to their environment survive in higher numbers. Homologous body structures – similarities among body parts of animals with backbones (vertebrates): Arms Wings Flippers Forelegs Vestigial organs Similarities in early development