Evolution in ActionChapter 15, section 3

Caribbean Anole Lizards

Anolis cybotesWay of life: Dwells on tree trucks and groundAdaptations: Long, strong legs for speed, stocky bodies

Anolis insolitusWay of life: Inhabits tree branchesAdaptations: Thin body, short legs, large toe pads

Anolis pulchellus Way of life: Stays in grassAdaptations: Slender, very long tails

Caribbean Anole Lizards

Distinct species of anole with the same body type occur on different islandsEx. A distinct species of twig dwelling anole is found

on each island

Scientists have compared DNA from all the species

Found that each specialized body type evolved independently on each island

Convergent EvolutionThe process by which unrelated species evolve

similar traits

Each Twig dwelling species evolved from different ancestors but evolved similar adaptations to similar environments

Divergent Evolution

The process by which the descendants of a single ancestor diversify into species that fit different parts of the environment

Smaller lizards may have been chased away by larger lizards, they could climb higher and hold on to branches more efficiently

Thousands of years of selection of more slender anoles with large forepaws and short legs produced a new species

Adaptive radiationA new population in a new environment

will undergo divergent evolution until the population fills many parts of the environment

Most common in islands

Artificial SelectionWhen a human breeder chooses individuals that

will parent the next generation

This process is called artificial selection because people (instead of nature) select which organisms get to reproduce

Farmers have cultivated numerous popular crops from the wild mustard, by artificially selecting for certain attributes.

Coevolution

Often seen in a number of species of flowering plants that coevolved with specific pollinators

Moth-pollinated plants often have spurs or tubes the exact length of a certain moth’s “tongue.”

Charles Darwin predicted the existence of a moth in Madagascar based on the size and shape of a flower he saw there.

Discovered about 40 years later.

When two or more species have evolved adaptations to each other’s influence