Evidence of Evolution 15.1

Blindfold Demo

I. Evolution Definitions A. Evolution- Change in inherited traits of a POPULATION (not individuals) over time. B. Variation- Changes between members of the same species caused by DNA mutations.

II. Charles Darwin A. It all began on the English ship, the HMS Beagle 1. Darwin worked as the naturalists 2. He took samples of living specimens and fossils

II. Charles Darwin B. Darwin’s observations in the Galapagos Islands 1. Species are unique, yet similar to species elsewhere 2. Species produce many offspring, but don’t overrun the earth

II. Charles Darwin 3. Individuals in a species struggle to survive a. Compete for food b. Compete for shelter c. Compete for water d. Etc

II. Charles Darwin C. Pigeon experiments 1. Darwin realizes that he can select and breed specific pigeons to get a desired trait.

II. Charles Darwin 2. Artificial Selection- Breeding organisms with specific traits in order to produce offspring with identical traits. a. Similar to a force in nature that causes changes

II. Charles Darwin D. Natural Selection- Organisms with favorable traits for their environment survive and reproduce. Organisms without favorable traits die! 1. Survival of the fittest!!! 2. Causes changes in populations a. Car demo

II. Charles Darwin E. Principles of Natural Selection 1. Organisms produce more offspring than can survive 2. Differences, AKA variations occur among individual species 3. Some variations are passed to the offspring

II. Charles Darwin 4. Some variations are helpful and help organisms to survive and reproduce better. 5. Over time, individuals with the helpful variations make up more of the population and often becomes a separate species.

RUEBEN VS. CARS DEMO

III. Evidence for Evolution A. Adaptations that increase survival 1. Structural 1. Structural a. Body parts Body partsBody parts b. Camouflage c. Mimicry

III. Evidence for Evolution 2. Physiological- Changes in metabolism a. Penicillin resistant bacteria b. Pesticide resistant insects

III. EVIDENCE FOR EVOLUTION B. Fossils & Transition Fossils 1. Archeopteryx: intermediate between reptiles & birds 2. Eustheopteron: fish to amphibians 3. Seymouria: amphibian to reptiles 4. Therapsids: reptiles to mammals

III. EVIDENCE FOR EVOLUTION C. Anatomical Evidence 1. Homologous Structures- Structure with similar origins (shape, function, etc) a. Provides evidence of common ancestor b. Ex: Forelimbs of whales, crocodiles and birds

Anatomical Evidence Homologous Structures

III. EVIDENCE FOR EVOLUTION 2. Analogous Structures- Structures that DO NOT have similar origin, but DO have similar functions a. Not closely related b. Wing of a butterfly and wing of a bird

Anatomical Evidence analogous structures

III. EVIDENCE FOR EVOLUTION 3. Vestigial Structures- Structures that no longer serve their original purpose 1. Ex: Human ear muscles, whale feet, blind mole-rat eyes

Anatomical Evidence vestigial structures

III. EVIDENCE FOR EVOLUTION 4. Embryology Evidence a. Embryo- Earliest stage of growth & development b. All embryos look similar

Evidence from Embryology

III. EVIDENCE FOR EVOLUTION 5. Biochemistry Evidence a. DNA is similar in all species b. Evidence of common ancestor

III. EVIDENCE FOR EVOLUTION c. The more DNA alleles in common, the more closely related two organisms are! 1) Humans & chimps have 97% of the same DNA