How did Dobzhansky and Mayr explain the origin of species
A. it happens through adaption by natural selection.
B. it happens through allopatric speciation
C. It happens through sympatric speciation
Both Dobzhansky and Mayr believed that the origin of species occurs through the process of natural selection, but they provided different explanations for the mechanisms driving this process.
A. Dobzhansky, in his work on population genetics, emphasized the role of adaptation by natural selection in driving the origin of species. He argued that the accumulation of genetic changes within populations, through the interaction of mutation, genetic recombination, and natural selection, leads to the emergence of new species with distinct characteristics. Dobzhansky believed that the genetic variation within a population provided the raw material for natural selection to act upon, resulting in the formation of new species over time.
B. Mayr, on the other hand, focused on the concept of allopatric speciation to explain the origin of species. He proposed that the formation of new species occurs when populations become geographically isolated from each other, preventing gene flow and leading to the accumulation of genetic differences. Over time, these genetic differences can become significant enough to prevent successful interbreeding between populations, resulting in the formation of new species. Mayr argued that isolation and geographic factors play a crucial role in driving speciation.
C. While both Dobzhansky and Mayr recognized the possibility of sympatric speciation (the formation of new species without geographic isolation), they put less emphasis on this mechanism. Sympatric speciation occurs when a subset of a population undergoes genetic changes that isolate them reproductively from the rest of the population, leading to the formation of a new species. This can happen through various factors, such as disruptive selection or chromosomal changes. However, both Dobzhansky and Mayr viewed allopatric speciation as a more prevalent and significant contributor to the origin of species.