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Human-mediated gene flow: The captive genetic management of threatened species is the only way in which humans attempt to induce gene flow in ex situ situation. One example is the giant panda which is part of an international breeding program in which genetic materials are shared between zoological organizations in order to increase genetic ...
Population bottleneck followed by recovery or extinction. A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as genocide, speciocide, widespread violence or intentional culling.
Macroevolution is guided by sorting of interspecific variation ("species selection" [2]), as opposed to sorting of intraspecific variation in microevolution. [3] Species selection may occur as (a) effect-macroevolution, where organism-level traits (aggregate traits) affect speciation and extinction rates, and (b) strict-sense species selection, where species-level traits (e.g. geographical ...
A growing number of scientists believe a sixth mass extinction event of a magnitude equal to the prior five has been unfolding for the past 10,000 years as humans have made their mark around the ...
Genetic erosion in agricultural and livestock is the loss of biological genetic diversity – including the loss of individual genes, and the loss of particular recombinants of genes (or gene complexes) – such as those manifested in locally adapted landraces of domesticated animals or plants that have become adapted to the natural environment in which they originated.
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth.Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms.
In this way, modern genetics undoubtedly lifts the veil from the evolution of biotypes, Jordanones and Linneones [i.e. variations within a species] [j] (a kind of microevolution), but that evolution of the higher systematic groups, which has always particularly occupied the minds of men (a kind of macroevolution), lies entirely outside its ...
Also a common sense concept linked to the chances of an effective rescue effect on islands, is the size of the island itself. This is called the ‘target‐area effect’, and it states that:The larger the area of the island the more likely a colonization is, either of active or passive immigrants. [1]