Chapter 15-3 Evolution in Action

A continuous process A heritable change in characteristics from one generation to the next It is ongoing today and can be observed, recorded, and tested Interactions between species affect their ongoing evolution

Scientists compare groups by finding patterns An example of this is the comparison of the Anole lizard species. Their body type matches the environment they live in. Anolis cybotes Anolis insolitus Anolis pulchellus ~ have longer legs because~ have thin bodies, short legs, and ~ have long tails because They mainly live on tree trunks. tails because they live on slender twigs they live in the grass

Convergent evolution: different species evolve similar traits Ex: Birds and bats Divergent evolution: descendents of a single ancestor branch out into species that each fit into different parts of the environment Ex: Humans emerging from monkeys

Adaptive Radiation: a new population is formed in a new environment Ex: an island will undergo divergent evolution until the population fills many parts of the environment

Artificial selection- a human breeder chooses individuals that will parent the next generation Ex: The variety of dog breeds is an example of artificial selection

Coevolution: when two or species have evolved adaptations to each other’s influence. Ex: Species of animals evolve strategies to avoid being eaten while the animals that eat them have strategies to keep eating them.

Humans are involved in coevolution also. They develop and use antibiotics to kill disease-causing bacteria Resistance: As this use of antibiotics increases, bacteria has developed adaptations to resist the effects of some of these antibiotics.