Suppose in a population of a single bird species, natural selection favors medium-sized beaks. Birds with very small beaks cannot break open the seeds they feed on; birds with large beaks cannot reach into the fruit to get the seeds at all. Natural selection in this case results inA.stabilizing selection.B.convergent evolution.C.adaptive radiation.D.disruptive selection.
Question
Suppose in a population of a single bird species, natural selection favors medium-sized beaks. Birds with very small beaks cannot break open the seeds they feed on; birds with large beaks cannot reach into the fruit to get the seeds at all. Natural selection in this case results inA.stabilizing selection.B.convergent evolution.C.adaptive radiation.D.disruptive selection.
Solution
The answer is A. Stabilizing selection.
Here's why:
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In this scenario, birds with medium-sized beaks are favored by natural selection. This means that they are more likely to survive and reproduce, passing on their genes to the next generation.
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Birds with very small or very large beaks are less likely to survive and reproduce because they cannot effectively feed on the seeds. This means that their genes are less likely to be passed on to the next generation.
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Over time, this will result in a population of birds with predominantly medium-sized beaks. This is an example of stabilizing selection, where the average trait is favored and extreme variations of the trait are selected against.
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This is not an example of convergent evolution (B), because that refers to different species evolving similar traits due to similar environments or ecological niches, not variations within a single species.
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This is also not an example of adaptive radiation (C), which refers to a rapid increase in the number of species with a common ancestor, each of which adapts to a different kind of environment.
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Finally, this is not an example of disruptive selection (D), which would favor the extreme variations of a trait over the average. In this case, the average (medium-sized beaks) is favored.
Similar Questions
Natural selection requires genetic variation, competition for limited resources, overproduction of offspring, and unequal reproductive success.The subset of finches that is capable of eating large seeds, while many others eat small seeds, is an example of which requirement?Multiple Choiceoverproduction of offspringgenetic variationunequal reproductive successcompetition for limited resources
Disruptive selection is a mechanism of natural selection thatMultiple choice question.favors two or more extreme phenotypes in a population.favors the intermediate phenotype in a population.favors only one extreme phenotype in a population.is seldom seen in natural populations.
Read each of the scenarios below. Then, select the option that best represents a scenario illustrating natural selection.A In a population of birds, those with larger beak sizes are better able to crack open tough seeds, providing them with a food source during periods of scarcity. Consequently, the average beak size in the population decreases.B In a population of flowers, those with a particular color variation attract more pollinators and produce more offspring. As a result, the proportion of flowers with that color variation decreases over generations.C In a population of rabbits, those with longer legs are more successful at outrunning predators and are more likely to survive and reproduce. Over time, the average leg length in the population increases.D In a population of fish, those with brighter colors are more easily spotted by predators, leading to higher mortality rates. As a result, the proportion of fish with bright colors increases over time.
The mode of natural selection in which two or more extreme phenotypes are fitter than the intermediate phenotype isMultiple Choicedirectional selection.stabilizing selection.disruptive selection.artificial selection.uniformitarianism.
Charles Darwin observed several species of finches on the Galápagos Islands, each with distinct beak shapes and sizes. These differences appeared to be adaptations to the specific types of food available on each island. For example, finches on islands with abundant hard seeds had stronger, thicker beaks, while those on islands with insects had thinner, sharper beaks.Which of the following observations by Darwin most directly led to his theory of natural selection?Question 2Answera.Variation in Traitsb.Adaptation to the Environmentc.Overproduction of Offspringd.Inheritance of Traits
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