What process, revealed by phylogeographic analysis, is evidenced by genetic breaks tracing back to barriers present during glacial maximums?

Answer

Range expansion and subsequent isolation leading to structured genetic variation.

Phylogeographic analysis maps genetic variation across geography, and for *C. oreganus*, these patterns often reflect the influence of the ice ages. Genetic breaks observed today can be linked to ancient barriers, such as large mountain ranges or substantial river systems, that acted as impediments during glacial maximums or drier interglacial periods. The pattern arises because the snakes expanded outward from multiple, separately surviving source populations (the refugia) as the ice retreated. This history results in genetic variation that is geographically structured, meaning relatedness correlates strongly with location, rather than being randomly distributed across the entire species range.

What process, revealed by phylogeographic analysis, is evidenced by genetic breaks tracing back to barriers present during glacial maximums?

Related Questions

What distinguishes the Crotalinae subfamily, to which *Crotalus oreganus* belongs?What biological event, contrary to popular myth, does the segmented rattle of *Crotalus oreganus* actually indicate?Under which broader historical classification were many populations now recognized as *C. oreganus* previously grouped?What major geological era is central to the deep evolutionary history and range dynamics of *C. oreganus*?What process, revealed by phylogeographic analysis, is evidenced by genetic breaks tracing back to barriers present during glacial maximums?What environmental pressures are cited as highly influential in shaping the diverse phenotypes within the *C. oreganus* species complex?What finding often results when comparing the deep genetic separations in *C. oreganus* molecular data with current subspecies classifications?What biochemical defense mechanism in *C. oreganus* varies significantly based on geographic location?What modern human activities pose a threat by causing fragmentation to localized *C. oreganus* populations?What is the general conservation security ranking assigned to the *Crotalus oreganus* designation by conservation bodies?
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