GENETICS AND EVOLUTION
EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A volcanic eruption creates a barrier separating two populations of rodents.
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A flock of sparrows is blown off course to an island far from their natural habitat.
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A mutation arises within a population of orchids that prevents the orchids from breeding with other populations of orchids.
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A single coconut is carried to a remote island in the Pacific Ocean by water currents.
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Detailed explanation-1: -A single coconut is carried to a remote island in the Pacific Ocean by water currents. Explanation: Speciation usually relies on the isolation (either geographical or reproductive) of a group of individuals. The coconut example would be unlikely to lead to speciation due to the fact that that it is only one coconut.
Detailed explanation-2: -Natural selection explains how genetic traits of a species may change over time. This may lead to speciation, the formation of a distinct new species.
Detailed explanation-3: -Sympatric speciation occurs when populations of a species that share the same habitat become reproductively isolated from each other. This speciation phenomenon most commonly occurs through polyploidy, in which an offspring or group of offspring will be produced with twice the normal number of chromosomes.
Detailed explanation-4: -How is sympatric speciation supposed to occur? The most common scenarios involve disruptive selection, that is, natural selection driving a population in two different directions at once. A population of herbivorous insects, for example, may be selected to use two very different types of plant growing in a single area.
Detailed explanation-5: -Allotropic speciation is more likely to occur in an isolated island. The island close to the mainland would allow gene flow which prevents the formation of new species.