Chapter 15: Theory of Evolution Section 1: History of Evolutionary Thought Section 2: Evidence of Evolution Section 3: Evolution in Action

Georges Cuvier French anatomist ( ) Reconstructed the appearance of unique organisms from fossil bones 1.Organisms in past differ greatly from any living species 2.Extinction 3.Many sudden changes in the kinds of organisms Catastrophism: sudden geologic catastrophes caused extinction of large groups of organisms at certain points in the past

Tornados, Hurricanes, Meteorites: abrupt events (catastrophes)

Charles Lyell English geologist ( ) Shared some of Cuvier’s thoughts Uniformitarianism: geologic processes that have changed the shape of the Earth’s surface in the past continue to work in the same ways Darwin: ideas fit with evidence from biology “The present is a key to the past”

Grand Canyon: took millions of years to form

Jean Baptiste Lamarck French Biologist ( ) Inheritance of acquired characteristics: individuals could acquire traits during their lifetimes as a result of experience or behavior, then could pass on those traits *not supported

Charles Darwin “On the Origin of Species by Means of Natural Selection” 1.Overproduction 2.Genetic Variation 3.Struggle to Survive 4.Differential Reproduction “Descent with modification” “Survival of the fittest”

Fossils Most powerful evidence of evolution Superposition: the lowest stratum was formed before the strata above it Fossils formed –Rapidly buried by fine sediment –Wetland, streams, lakes, volcano Section 2: Evidence of Evolution

Fossil links between –Fishes and Amphibians –Dinosaurs and Birds –Reptiles and Mammals Video: Transitional Species Video: Fish with fingers Video: How do we know evolution happens

Seminar Science Video: –Research in Gobi Desert (Dino) golb_N –Fossil Preparation (Dino) Prepare_N –Microraptor (Dino) micro_N –Research on the origin of feathers 1&2 (Dino)

Homologous structures Anatomical structures that occur in different species and that originated by heredity from a structure in the most recent common ancestor of that species They each have different functions, but are constructed of the same anatomic elements

Analogous Structures Structures that have closely relate functions, but do not derive from the same ancestral structure Wings: serve the same function, but derived independently

Vestigial Structures Structures that seem to serve no function but resemble structures with functional roles in related organisms. Any ideas?

Embryology Some stages of vertebrate embryo development are very alike

Phylogenetic tree diagram

Section 3: Evolution in Action How does evolution really work Toxic newts Ancient farmers of the amazon: coevolution Evolution of Camouflage

Peppered Moths Most are white with black spots Rare mutant moth will be black and caught by predators Industrial Revolution, birch trees became covered with pollutants and turned black Black survived more than white

Divergent evolution Descendents of a single ancestor diverged into species that each fit different parts of the environment Rhea in S. America Emu in Australia Ostrich in Africa Evolved from a common ancestor but are now in widely separated regions

Divergence among Honeycreepers in the Hawaiian islands Each with a beak specialized for its food, evolved from a single ancestor to fit ecological niches Undergoes divergence until the population fills many parts of the environment: Adaptive radiation

Convergent Evolution: each came from different ancestors, but evolved similar adaptations to similar habitats Evolved in isolation on the Australian continent

Artificial Selection Human breeder chooses individuals that will parent the next generation * dogs, cats, horses, etc * plants (rice, flowers, vegetables, etc)