Mechanisms of Evolution Convergent Divergent Adaptive radiation

CONVERGENT - Convergent evolution is the process by which unrelated or distantly related organisms evolve similar body forms, coloration, organs, and adaptations. - independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

CONVERGENT

Analogous Structures Structures of different species having similar or corresponding function but not from the same evolutionary origin the wings of bats, birds, and insects evolved independently from each other but all are used to perform the function of flying

Analogous Structures

DIVERGENT Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species Divergent evolution is the process of two or more related species becoming more and more dissimilar

DIVERGENT usually a result of “diffusion” of the same species to different and isolated environments which blocks the gene flow… similarity is most likely due to the common origin

Homologous Structures Structures derived from a common ancestor or same evolutionary or developmental origin Homologous structures may not necessarily perform the same function but they share a common ancestral origin The forelimbs of humans and bats are homologous structures. Although they are used differently, the basic skeletal structure is the same and they are derived from the same embryonic origin

Homologous structures

ADAPTIVE RADIATION Adaptive radiation is an evolutionary pattern, in which many related species evolved from a single ancestral species. It’s an example of divergent evolution – Hawaiian honeycreepers (23) – Darwin’s finches (13+)