Linking the evolution of the phenotype to the underlying genotype is a key aim of evolutionary genetics and is crucial to our understanding of how natural selection shapes a trait.
In evolutionary biology, we might ask which factor shaped a particular trait or behavior.
To fully understand how natural selection is shaping a given trait, it is necessary to understand the constraints placed on adaptation at the phenotypic level by the underlying genetic architecture (Sokolowski 2001; Orr 2005).
P factors preferentially insert and mutate the Drosophila X-linked singed locus, which affects bristle shape, a trait that can be seen with a magnifying glass.
Here, we characterize variation in and test for an association between SARPs and head shape, a trait under strong sexual selection, in the stalk-eyed fly, Teleopsis dalmanni.
Using Malawi cichlid hybrids, they showed that lower jaw shape, a trait under strong directional selection [ 22], did not exhibit TS while the shape of the neurocranium, a trait not under directional selection, did.
Given that evolution might have shaped an adaptive, integrated, multi-trait response to multiple natural stressors, when do we expect organisms to be able to co-opt their evolved integrated phenotype to cope well with a novel mix of old and novel stressors?
Those traits also shape a later trilogy, themed around summer, autumn and winter: in the first, a woman pieces together the day her husband disappeared at sea; in the second, two strangers meet in a graveyard, yet have somehow known each other for a lifetime.
Together, these approaches to coevolutionary analysis can help us to understand the extent to which geographic selection mosaics have shaped trait distribution across landscapes in this model system.
Naturalists tried to understand how selection could have shaped the traits of interacting pollinators and plants.
