2004) proposed that this species complex might probably have arisen due to a speciation process that assumes a constant evolution rate and allopatric speciation
(Grant, 1985), a hypothesis based on Wright (1943) theory of "isolation by distance".
nux through allopatric speciation
in forest refugia, as has been similarly hypothesized for African forest fruitbat species of the genera Myonycteris Matschie, 1899 (Nesi et al.
The intricacies of the Gould-Eldredge interaction, their efforts to address their critics, and the relationship of their proposals concerning speciation models and in particular concerning Ernst Mayr's allopatric speciation
model are thoroughly and fairly explicated.
In allopatric speciation
, individuals of a species become geographically isolated from each other by external factors such as mountains or estuaries.
He follows with description of neural-developmental premises of evolutionary adaptation, including evolution and stress responses and behavioral adaptation to changes in environment, ontogeny, and intragenerational developmental plasticity; epigenetics of circumevolutionary phenomena and the mechanism of evolutionary change, including transgenerational developmental plasticity and the evolution of metazoans and their control system; and the origins of evolutionary novelty, evolution by loss or by reverting to ancestral characters, neural crest-determined evolutionary novelties, evolutionary convergences, species and allopatric speciation
, and sympatric speciation.
Flightless insects are thus particularly constrained in their distribution by current conditions, and so these high mountains in East Africa provide a situation conducive to allopatric speciation
My discussions below refer to the history of allopatric speciation
in vertebrate animals like amphibians, reptiles, birds and mammals.
However, theoretical studies have demonstrated that sympatric speciation can occur and can cause species to form much more rapidly than by allopatric speciation
(Turelli et al.
The mere fact that punk eek is wholly founded on Ernst Mayr's allopatric speciation
(a concept alluded to by Darwin himself) belies the fact that it is not the antithesis of "gradualism" but a complement to it as one (Gould would argue the primary one) of several paths possible for the diversification of a lineage of organisms.
For example, morphological similarity superficially suggests widespread species, high gene flow, few barriers to dispersal, a dearth of allopatric speciation
and, therefore, greater probability that other modes of speciation have contributed significantly to marine biodiversity (2).
This distribution pattern suggests either classical allopatric speciation
or speciation via the isolation of peripheral populations to the coastal plain during the radiation in these lineages (Mayr 1947, 1963, 1982, Garcia-Ramos and Kirkpatrick 1997), with secondary invasion of the coastal plai n by the wide-ranging species after reproductive isolation was established.
Most scientists believe that allopatric speciation
, where different species arise from an ancestral species only after breeding populations have become physically isolated from each other, is the dominant mode of speciation both on land and in the sea.