The North American flying squirrel and the Draco lizard of Southeast Asia have both evolved a membrane between their limbs that allows them to glide between trees in their habitats. Given that the species are distantly related, which of the following patterns of evolution would explain the development of this anatomical structure in both organisms?Parallel evolutionDivergent evolutionConvergent evolution

Question

The North American flying squirrel and the Draco lizard of Southeast Asia have both evolved a membrane between their limbs that allows them to glide between trees in their habitats.  Given that the species are distantly related, which of the following patterns of evolution would explain the development of this anatomical structure in both organisms?Parallel evolutionDivergent evolutionConvergent evolution

Quizplus · Accepted Answer

11ecba2d_1014_405e_a3bf_851660448991_MD0008_00 According to the theory of natural selection, organisms possessing traits that are best suited to their environment are more likely to survive and reproduce (ie, pass on their genes) than those with less favorable traits. As a result, traits/phenotypes that increase chances of survival prevail in the population, causing the species to adapt to its environment over time (ie, evolve). However, the patterns of evolution across time often vary depending on the environmental pressures faced by different species. If two species inhabit similar environments, they often evolve analogous (comparable) characteristics in response to facing comparable environmental pressures (eg, habitat, food availability, predation). In contrast, if two species inhabit distinct environments with different environmental pressures, they are likely to evolve unique phenotypes that are best suited to their different environments. Accordingly, the flying squirrel and Draco lizard have a distant evolutionary relationship, yet both have evolved an anatomical structure for gliding between trees. Because they both live in tree-dense habitats, it is likely that both species independently acquired a membrane between their limbs to adapt to similar environmental pressures and improve their chances of survival. For example, enhanced mobility or "gliding" between trees may have simplified foraging for food or aided in predator avoidance. Because the evolution of this feature occurred independently in these two very distantly related species, this is an example of convergent evolution (Number III). (Number I) Parallel evolution occurs when two more closely related species (ie, descended from a more recent common ancestor) continue to evolve the same characteristics to adapt to similar environments. (Number II) Divergent evolution occurs when two species descended from a recent common ancestor inhabit contrasting environments and evolve distinct characteristics that allow them to better adapt to their differing environmental pressures. Educational objective: Convergent evolution leads to similar characteristics in distantly related species that are exposed to similar environmental pressures. Parallel evolution also leads to similar characteristics in species found in similar environments but occurs in species with a more recent common ancestor. Divergent evolution leads to unique characteristics in somewhat closely related species that face contrasting environmental pressures.

The North American Flying Squirrel and the Draco Lizard of Southeast