Search results
Results From The WOW.Com Content Network
One example of natural speciation is the diversity of the three-spined stickleback, a marine fish that, ... Modes of Speciation. A Series of Books in Biology.
In evolutionary biology, sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography , sympatric and sympatry are terms referring to organisms whose ranges overlap so that they occur together at least in some places.
Three-spined stickleback fish have been a frequently studied species in ecological speciation.. Ecological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species.
In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. [1] An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation .
Allopatric speciation (from Ancient Greek ἄλλος (állos) 'other' and πατρίς (patrís) 'fatherland') – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model [1]: 86 – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.
Species with differentiated populations, such as ring species, are sometimes seen as an example of early, ongoing speciation: a species complex in formation. Nevertheless, similar but distinct species have sometimes been isolated for a long time without evolving differences, a phenomenon known as "morphological stasis". [ 19 ]
Brown and Wilson viewed character displacement as a phenomenon involved in speciation, stating, "we believe that it is a common aspect of geographical speciation, arising most often as a product of the genetic and ecological interaction of two (or more) newly evolved, cognate species [derived from the same immediate parental species] during ...
Documented examples are found in a wide range of organisms: both vertebrates and invertebrates, fungi, and plants. The secondary contact of originally separated incipient species (the initial stage of speciation) is increasing due to human activities such as the introduction of invasive species or the modification of natural habitats. [6]