Cell Biology
Patterns of evolution lead to the development different phenotypes. There are three key patterns of evolution seeng among populations in reproductive isolation fro one another: divergent evolution, convergent evolution, and parallel evolution.
Divergent evolution occurs when closely related lineages face different selection pressures, resulting in highly different phenotypes. Convergent evolution takes place when distantly related species face similar selection pressures, causing them to evolve similar phenotypes over time. Parallel evolution happens when closely related species experience similar selection pressures, leading to their phenotypes remaining similar as they evolve in isolation from each other. Understanding these patterns helps to shed light on the evolutionary processes that have shaped life on Earth and beyond.
Lesson Outline
<ul> <li>Reproductive isolation and separate species</li> <ul> <li>Divergent evolution</li> <ul> <li>When closely related lineages face different selection pressures, causing phenotypes to diverge</li> </ul> <li>Convergent evolution</li> <ul> <li>When distantly related species face similar selection pressures, eventually resulting in similar phenotypes</li> <li>Example: birds vs. bats</li> </ul> <li>Parallel evolution</li> <ul> <li>When closely related species experience similar selection pressures, leading to similar phenotypes over long stretches of time</li> <li>Example: placental vs. marsupial mammals</li> </ul> </ul> <li>Key differences between convergent and parallel evolution</li> <ul> <li>Convergent starts with distantly related species; parallel starts with closely related species (who are nonetheless reproductively isolated)</li> </ul> </ul>
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FAQs
The main patterns of evolution are convergent evolution, divergent evolution, and parallel evolution. Convergent evolution occurs when unrelated species develop similar traits due to similar selection pressures. Divergent evolution is the process where a single species or group with a common ancestor evolves into distinct species due to differing selection pressures. Parallel evolution refers to the development of similar traits in related species that have already diverged from a common ancestor, usually due to similar selection pressures in their environment.
Reproductive isolation plays a significant role in divergent evolution by preventing the interbreeding of two different populations of a species. It can result from various factors, such as geographical barriers, mating preferences, or genetic incompatibility. When populations are reproductively isolated, they accumulate genetic differences over time due to different selection pressures and genetic drift. This process can eventually lead to the formation of distinct spec
Convergent and parallel evolution both result in similar phenotypic changes in species due to similar selection pressures within their respective environments. In convergent evolution, unrelated species develop similar traits because they face comparable challenges or exploit similar ecological niches. Meanwhile, parallel evolution occurs in related species that have already diverged from a common ancestor but still face similar selection pressures. In both cases, the organisms evolve similar adaptations to overcome environmental challenges, which results in analogous phenotypic changes despite the differences between their evolutionary processes.
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