EVOLUTION and DIVERSITY A process of change over time Existing - Genetic diversity – Evidence Geologic fossil record shows -

The fossil record indicates similarity – Comparative anatomy- Examples: Forelegs of frogs, horses, arms of humans, flippers of a whale, wings of bats and birds-

Comparative Cytology- Comparative Embryology …EX. Humans still have gill slits, indicating the ancestor may be sea-like Comparative Biochemistry- EX. hemoglobin in animals and chlorophyll in plants are similar

Natural Selection- - Only the organisms that can - Characteristics, - The population will change - DARWIN

Conditions for Evolution Overproduction- Competition- New Traits will arise in a species as a result of variation (unique traits from parents- Selection by environment- organisms with adaptive values will have an advantage and will survive and reproduce… The changing environment is the -

Evolutionary Patterns Changes in species are related to environment Species with short repro cycles and many offspring will evolve quickly Failure to adapt may lead to extinction Rate of Evolution – gradualism (most), punctuated equilibrium (few- rapid changes) Example: Bacteria and its resistance to antibiotic- resistant bacteria will survive and reproduce Example: Insects become resistant to DDT, pesticide…and reproduce

Geographic Isolation- a species is separated by a barrier (mts, water) different environments select for different traits until the species is unable to interbreed….new species arise…Example: Darwin’s Finches in the Galapagos Islands Variation in genes lead to new species this is due to Mutations (most are harmful, but few are beneficial to a species) and Genetic Shuffling (a result of crossing over, sexual repro)

Results of Genetic Variation Structural change-changes in bones, skin and limbs Functional Change- changes in enzymes and proteins Behavioral Change- changes in mating, thinking Extinction- disappearance of entire species, usually due to environmental change and failure to adapt (65% of all species that have lived on earth have gone extinct!!!)