Natural Selection Study Quiz

Darwin observed that the Galapagos Tortoises had different shaped shells which seemed to be based on the available food found on each island. This suggests that the tortoises' shell morphology was influenced by the specific vegetation and food sources present on each island. This observation provides evidence for the theory of natural selection, as the tortoises with shells that were better suited to their respective environments would have had a higher chance of survival and reproduction.

A Snowshoe Hare changes its fur color from brown to white to blend in with the snow during the winter. This describes camouflage because the hare is able to change its fur color to match its surroundings, making it difficult for predators to spot it in the snow. This adaptation allows the hare to blend in and remain hidden, increasing its chances of survival.

Kettlewell discovered that natural selection was responsible for the change in color of the population of moths. This means that the moths with advantageous traits, such as a color that camouflages them against predators, were more likely to survive and reproduce. Over time, this led to a higher proportion of moths with the advantageous trait in the population. This observation supports the theory of evolution by natural selection, which states that individuals with traits that increase their fitness are more likely to pass on those traits to future generations.

Shivering is a physiological adaptation that helps humans survive in cold temperatures. When the body is exposed to cold, shivering occurs as a rapid, involuntary contraction of muscles. These muscle contractions generate heat, helping to maintain the body's core temperature. This response is part of the body's thermoregulation mechanism, which is crucial for preventing hypothermia in cold environments.

Darwin did not identify replication as a principle that affects natural selection. Replication refers to the process of copying genetic material to produce offspring, which is a fundamental aspect of reproduction. However, it is not considered a principle that directly influences natural selection. Natural selection is driven by factors such as overproduction, adaptation, and variation, which determine the survival and reproductive success of individuals in a population.

In Origin of Species, Darwin proposed that new species arise through natural selection. This process involves the differential survival and reproduction of individuals with favorable traits, leading to the accumulation of advantageous traits in a population over time. Natural selection acts on variations within a population, selecting those traits that increase an organism's fitness and allowing them to pass on their genes to the next generation. This gradual accumulation of small changes over generations eventually results in the formation of new species.

Rabbits and birds having the same bones in the same order in their forelimbs, despite using them for different purposes, is an example of homologous structures. This suggests that these species share a common ancestor and have evolved from it, retaining the same basic bone structure. The similarity in bone structure indicates a common evolutionary origin, even though the functions of the forelimbs have diverged in these two species.

Darwin observed that isolation played a crucial role in the development of new species on the Galapagos Islands. Isolation refers to the separation of populations, either geographically or reproductively, which prevents gene flow between them. This isolation allows for the accumulation of genetic variations over time, leading to the formation of distinct species. Therefore, isolation is the key factor identified by Darwin in the process of speciation.

Darwin was stating that the commonly held belief among naturalists, including himself in the past, that each species was independently created is incorrect. He is implying that this belief has been proven wrong through his research and understanding of the origin of species.