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Geographic isolation refers to the separation of members of a population by a physical barrier, such as a mountain or body of water, which disrupts the gene flow between them and begins the process of speciation. Geographic isolation of a species occurs as a result of physical changes in its natural environment.
27 Απρ 2012 · The focus here is on outlining some of these major developments, specifically in the context of paleontology, by emphasizing the significance of geographic isolation and allopatric speciation, punctuated equilibria, and the Turnover Pulse Hypothesis to evolutionary theory.
Geographical isolation represents a major speciation factor in most animals and plants and causes a physical barrier to gene flow between populations, leading to the emergence of new species [11,43]. Barriers to gene flow (reproductive barriers in sexual organisms) may be raised by neutral processes such as genetic drift.
12 Ιουν 2022 · Allopatric speciation is a type of speciation in which biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the population can no longer interbreed. Example: Charles Darwin’s Galápagos Finches.
18 Απρ 2012 · Geographic isolation (vicariance) or geographic merging (geodispersal) can occur for a variety of reasons (sea level rise, splitting of continents, mountain building). In addition, the growth of a large supercontinent (or breakup) may change the climatic zonation on the globe and form a different type of barrier for species migration.
Defining speciation. Speciation is a lineage-splitting event that produces two or more separate species. Imagine that you are looking at a tip of the tree of life that constitutes a species of fruit fly. Move down the phylogeny to where your fruit fly twig is connected to the rest of the tree.
1 Φεβ 2010 · “Ecological speciation” is defined as the case in which divergent selection leads to reproductive isolation, with speciation under uniform selection, polyploid speciation, and speciation by genetic drift defined as “nonecological.”
