Evolution H I Biology Flashcards
Evolution
The process of change in the heritable characteristics of a population
Selective breeding
The art of artificially selecting domesticated animals for desirrd traits. (Driven by human force)
Homologous structures
Similar bones in the same positions but different functions. They have a common ancestor.
Analogous structures
Parts that ate similar in function but anatomy is different. They dont have a common ancestor.
Convergent evolution
When organisms of different origins become similar to perform a similar function in a similar environment.
Gradual divergence
If a pop. becomes separated they wull evolve in diff. ways. (Characteristics will gradually change)
Speciation
A pop. diverging to form 2 separate species.
Adaptive radiation
When organisms of thr same species have slight variations in their features due to their diff. environ.
Molecular genetics
Comparison of the base sequences of variable regions of DNA talen from diff. organisms
Natural selection
The mechanism for how evolution occurs
Polygenic traits
Traits that are controlled by more than two genes. Graph is bell shaped curve.
Directional selection
Shifts L or R. Favoring what had been tare individuals. Common during environmental change. Long neck giraffe
Disruptive selection
Occurs when environmental conditins favor individuals at both extremes of the phenotypic range over intermediate (two peaks)
Stabilizing selection
Favors intermediate variants and acts against extremes. This reduces variation.middle curve increases
Gene pool
The complete set of alleles of all genes in a pop.
