The development of what became known as the biological species concept began with a paper by Theodosius Dobzhansky in 1935, and was amplified by a mutualistic interaction between Dobzhansky, Alfred Emerson and Ernst Mayr after the second world war. Hybridization without guilt: gene flow and the biological species concept. Building a phylogenetic tree. The genetic species concept assumes that the biological factors of gene flow and reproductive isolation are operative but the way to define species is by a measure of the genetic differences or distance among population. Species is the fundamental unit of taxonomic classification. The biological species concept defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance. this concept states that a species is a group of populations whose members interbreed, thus, gene flow occurs between populations of a species; the absence of gene flow plays a key role in the formation of new species, as well as in keeping them apart once their potential to interbreed has been reduced If the rate of gene flow is high enough, then two populations are considered to have equivalent allele frequencies and therefore effectively be a single population. Critics of the biological species concept come from the fields of both botany and zoology. Both allopatric and sympatric speciation are the product of reproductive isolation, which reduces gene flow between populations.Reproductive isolating mechanisms prevent two individuals from distinct species from interbreeding to produce viable and fertile hybrid offspring. It is probably the species concept most familiar to biologists in diverse fields, such as conservation biology, … There is no universal species concept—one that applies to all organisms. Define morphospecies and explain how this concept can be useful to biologists. Define biological species (E. Mayr)' 4. If the two populations constantly interbreed (have a high gene flow… Biodiversity and natural selection. The biological species, according to Grant (1957), is defined as “a community of cross … Biological species concept. Part C - Gene flow and the biological species concept Recall that the biological species concept defines a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring. Distinguish between prezygotic and postzygotic isolating mechanisms. The biological species concept (BSC) is the cornerstone of the neo-Darwinian thinking. A tacit assumption of speciation research is that species are real evolutionary units. Download : Download full-size image; Figure I. Parapatric speciation in a homogeneous environment caused by gene flow limitation. Learn vocabulary, terms, and more with flashcards, games, ... as defined by the biological species concept, is (are) correct? A biological species is a group of individuals that can breed together . 6. Greek philosopher Plato proposed concept of “eidos” or species and believed that all objects are shadows of the “eidos”.According to Stebbins (1977) species is the basic unit of evolutionary process.