pages 308-311

Change of heritable traits of a population over time

Evolution of a population is due to environment AND the interaction of other species

Evolution is…

Convergent evolution:

Organisms with different ancestors become more alikedue to common environment

Ex. fish and whales

Compare analogous structures: same function but different development

Types of Evolution

Divergent evolution: populations

become more and more dissimilarto adapt to the environment

Ex: Appearance of birds with different sized beaks that are specific for size of bird seed

Compare homologous structures to see shared ancestry

Homologous structure: similar body part but may have different functions

Types of Evolution

Population undergoes divergent

evolution until it fills all areas of the environment

Adaptive radiation: a type of divergent evolution

When the dinosaurs died out,

mammals evolved to fit

niches once used by

dinosaurs

Darwin’s Finches are

an example of adaptive

radiation. They can be

found in all areas of the

island: the ground, in

bushes, in all levels of

the trees.

Co-evolution: two species

evolve in response to each other over a long period of time

This leads to a close relationship between the two species

Ex: parasites and hosts, plants and pollinators

Types of Evolution

Types of Evolution

Ex: Rough-skinned newt and garter snake

Newt evolved to produce neurotoxins then the snake evolved resistance to this toxin through genetic mutations

Birds and flowers,Humans and bacteria are other examples

Types of Evolution