A certain species of frog comes in two different colors, green and brown. A population of these frogs live in and along a river. In 1980, a very large drought occurred, causing most of the river to dry up. Most of the plant life around the river died as well.
Why did the green frog population decrease after the drought?
The green frog population likely decreased after the drought because their green coloration allows them to camouflage and blend in with the plant life around the river. With most of the plant life dying due to the drought, the green frogs would become more visible and exposed to predators. This increased visibility and lack of suitable habitats for camouflage would make them more vulnerable to predation, resulting in a decline in their population.
Why did the color of the peppered moth change?
The moths’ life cycle changed.
The environment changed.
The amount of variation in the moth population changed.
The number of individual moths in the population changed.
The color of the peppered moth changed primarily because of the environment change. During the Industrial Revolution in England, the environment became heavily polluted due to the burning of coal, resulting in dark soot and pollution covering most surfaces, including trees. The original light-colored peppered moth individuals that were well camouflaged against the light-colored lichen-covered tree trunks became increasingly visible to predators. However, a small percentage of the moth population had a genetic variation that gave them a darker coloration, allowing them to blend in better with the darkened environment. As a result, these darker-colored moths had greater survival rates as they were less likely to be preyed upon, leading to an increase in the frequency of the dark coloration in future generations. This change in the moth population's coloration was driven primarily by the impact of the environmental pollution.
A coastal forest was home to a type of burrowing rodent that was not found anywhere else in the world. A year ago, a species of large predator moved to the forest, but the rodents were able to escape by hiding in narrow underground tunnels. Recently, a hurricane flooded most of the forest. A few days later, scientists studying the area found that no members of this species remained.
Which best describes why the species became extinct?
A natural disaster killed off the population by flooding their habitat.
Large predators moved to the area where the rodents lived.
They had no genetic variation so they could not adapt to changes in the habitat.
They were not big enough to compete with the new, larger species for food.
The most accurate description of why the species became extinct in this scenario is "A natural disaster killed off the population by flooding their habitat." The hurricane flooding the forest likely caused significant destruction to the rodents' habitat, leading to their inability to survive and resulting in their extinction.
Explain the relationship between mutations, adaptations, natural selection, and extinction.
Mutations, adaptations, natural selection, and extinction are interconnected concepts that play a role in the evolution and survival of species.
Mutations are random changes in an organism's DNA sequence that can arise spontaneously or due to external factors like radiation or chemicals. Mutations are essential as they introduce genetic variation into a population, which is the raw material for evolution.
Adaptations are traits or characteristics that allow an organism to better survive and reproduce in its environment. These adaptations can be behavioral, physiological, or anatomical. Adaptations can arise through mutations, but they can also be acquired through other mechanisms like genetic recombination or gene flow.
Natural selection is the process by which certain traits or adaptations become more or less common in a population over time. It occurs because individuals with traits that are beneficial for their specific environment are more likely to survive, reproduce, and pass on their advantageous traits to the next generation. On the other hand, individuals with less favorable traits are less likely to survive and reproduce. This leads to the accumulation of beneficial traits and the gradual adaptation of a population to its specific environment.
Extinction occurs when an entire species ceases to exist. It can happen due to various factors, such as changes in the environment, competition with other species, predation, or inadequate adaptations to new conditions. Extinction can be a natural process, but human activities such as habitat destruction, pollution, and overhunting have dramatically accelerated the rate of extinction in recent times.
In summary, mutations introduce genetic variation, which can result in adaptations. Natural selection acts on these adaptations, favoring traits that increase an organism's survival and reproductive success. Over time, this process can lead to the adaptation of a population to its environment. However, if a species fails to adapt sufficiently to changes or faces severe environmental challenges, it can result in extinction.