15.3 Evolution in 15.3 Evolution in ActionAction

StandardsStandards

CLE 3210.5.5 Explain how evolution contributes to the amount of biodiversity

CLE 3210.5.3 Explain how genetic variation in a population and changing environmental conditions are associated with adaptation and the emergence of new species.

How does evolution How does evolution work?work? Natural Selection can work in several ways:Natural Selection can work in several ways:

Convergent Evolution: the process by which unrelated species become more similar as they adapt to the same kind of environment

Divergent Evolution: the process by which two or more related but reproductively isolated populations become more and more dissimilar

Co-Evolution: the process by which two or more unrelated species evolve together because of a symbiotic relationship.

Convergent EvolutionConvergent Evolution

How it happens:How it happens:

Example:Example:

Two genetically different species adapt to the same environment in similar ways resulting in similar phenotypes.

Convergent Convergent EvolutionEvolution

Leads to Leads to analogous analogous structures:structures:

Divergent Evolution

How it happens:

Adaptive Radiation:

One species branches off into two or more different species due to changes in environment or behavior.

an evolutionary pattern in which many species evolve from a single ancestral species

Divergent EvolutionDivergent Evolution

Leads to Leads to homologouhomologous s structures:structures:

Co-Evolution

How it happens:When two different species are dependent on each other; if one changes the other must adapt or go extinct.

Artificial Selection

Natural Selection = environment determines desirable traits

Artificial selection = humans determine desirable traits

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Compare and contrast natural selection with artificial selection