Star-nosed mole: Pre-questions for discussion Introduction to Evolution Star-nosed mole: Pre-questions for discussion Pink snout has 22 finger-like projections that can touch 12 objects in less than 1 second. Q: Why is this helpful? Lives underground and has paddle shaped feet Has great hearing but very poor vision? Q: Why?

The Process of Evolution DNA Mutation Changes in Genotype Changes in Phenotype Adaptations in Populations Changes in the Gene Pool New Species Extinction Evolution

Objectives Today I will know... Who is Charles Darwin The meaning of survival of the fit That Charles Darwin believed that individuals are more likely to survive if they have variations best suited to the environment. Darwin’s theory of evolution is based on the ideas of natural variation and natural selection. That species produce more offspring than can possibly survive. Darwin’s theory of Evolution by natural selection is a process of change in species over time.

A 19th century (1800s) biologist Who is Charles Darwin? A 19th century (1800s) biologist Observed adaptations of plants and animals Adaptation- a feature that allows an organism to better survive in its environment Old Darwin Young Darwin Adaptations vary with different environments

Most famous research took place at the Galápagos Islands ~near the equator west of South America GREAT BRITAIN EUROPE NORTH AMERICA ATLANTIC OCEAN The Galápagos Islands AFRICA Pinta Genovesa Marchena Equator SOUTH AMERICA Santiago Daphne Islands Pinzón AUSTRALIA Fernandina PACIFIC OCEAN Isabela Figure 22.5 The voyage of HMS Beagle For the Discovery Video Charles Darwin, go to Animation and Video Files. Santa Cruz Andes Cape of Good Hope Santa Fe San Cristobal Tasmania Florenza Española Cape Horn New Zealand Tierra del Fuego

Darwin’s Focus on Adaptation Darwin discovered: Adaptations to the environment AND the origin of new species are closely related processes Examples- Galápagos finches & Tortoises Beak Shape Shell Shape & Neck Length

(a) Cactus-eater (c) Seed-eater (b) Insect-eater Fig. 22-6 Figure 22.6 Beak variation in Galápagos finches (b) Insect-eater

IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT! Fig. 22-6a Figure 22.6 Beak variation in Galápagos finches (a) Cactus-eater

IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT! Fig. 22-6b Figure 22.6 Beak variation in Galápagos finches (b) Insect-eater

IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT! Fig. 22-6c Figure 22.6 Beak variation in Galápagos finches (c) Seed-eater

Darwin’s two main ideas: Descent with modification: All organisms are related through descent from an ancestor that lived in the past Fossil evidence proves this! Natural selection: individuals that are best suited to their environment survive and reproduce Increases the adaptation of orgs to their envmnt If envmnt changes, new adaptations will appear OVER TIME b/c of natural selection

Tortoises necks- Darwin’s evidence of adaptations

Darwin’s 4 Observations Observation #1: Members of a population often vary greatly in their traits

Observation #2: Traits are inherited from parents to offspring (genetics) Observation #3: All species are capable of producing more offspring than the environment can support Observation #4: Because there is not enough food or other resources (limiting factors), many of these offspring do not survive

Have more offspring survive Survival of the Fit Individuals with traits that give a better chance of surviving and reproducing Have more offspring survive Unequal ability of individuals to survive and reproduce Leads to the accumulation of favorable traits in the population over generations

Survival of the Fit Survival of the Fit: individuals with favorable heritable traits survive and reproduce at a higher rate than other individuals

(a) A flower mantid in Malaysia (b) A stick mantid in Africa Fig. 22-12 (a) A flower mantid in Malaysia (b) A stick mantid in Africa Figure 22.12 Camouflage as an example of evolutionary adaptation

(a) A flower mantid in Malaysia Fig. 22-12a Figure 22.12 Camouflage as an example of evolutionary adaptation (a) A flower mantid in Malaysia

(b) A stick mantid in Africa Fig. 22-12b Figure 22.12 Camouflage as an example of evolutionary adaptation (b) A stick mantid in Africa

Individuals do not evolve; populations evolve over time… Important Notes about Evolution Individuals do not evolve; populations evolve over time… Natural selection can only increase or decrease heritable traits in a population N.S. does not create new traits! Local environment determines traits selected for or selected against