Answer: Invasive species can harm both the natural resources in an ecosystem as well as threaten human use of these resources. An invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and other means.
Directional selection is a type of natural selection that favors one extreme phenotype over the mean or another extreme. Examples of directional selection include giraffes that have long necks and the darkening of London's peppered moths after the Industrial Revolution.
Stabilizing selection, also known as purifying selection, is a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value. An example of stabilizing selection is birth weigh in humans.
Disruptive selection is a type of natural selection that shows a preference toward the reproduction of genetic material at the extremes within a population.One of the most studied examples of disruptive selection is the case of London's peppered moths.
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Colonized countries are forced to rely on manufactured goods from their mother countries and prevents development of industry.