Criteria used to make an argument that a trait is an adaptation that arose by natural selection (Brandon, 1991). The only real restriction to the order is that biological function needs to come first so that the phenotype under study is clear to all following group members.
| Criteria . | Brief Descriptions of Criteria . |
|---|---|
| 1) Biological function | Description of the phenotype students will be studying. What is the physiological, physical manifestation of the trait? This is also known as proximal function or how the trait functions in current ecological time. |
| 2) Fitness function | How does the trait impact survival and/or reproduction? |
| 3) Phylogenetic history | Is the trait evolutionarily new to the group under study? What was the ancestral state of the trait, and what is the distribution of the trait across the phylogenetic history of the groups that possess the trait? |
| 4) Heritability | Is there a genetic basis for variation in the trait that can allow it to respond to selection? |
| 5) Population genetic structure | Do past or current selective environments support the selective arguments being made above? |
| Criteria . | Brief Descriptions of Criteria . |
|---|---|
| 1) Biological function | Description of the phenotype students will be studying. What is the physiological, physical manifestation of the trait? This is also known as proximal function or how the trait functions in current ecological time. |
| 2) Fitness function | How does the trait impact survival and/or reproduction? |
| 3) Phylogenetic history | Is the trait evolutionarily new to the group under study? What was the ancestral state of the trait, and what is the distribution of the trait across the phylogenetic history of the groups that possess the trait? |
| 4) Heritability | Is there a genetic basis for variation in the trait that can allow it to respond to selection? |
| 5) Population genetic structure | Do past or current selective environments support the selective arguments being made above? |