Card 0 of 6
A bat's wing and a bird's wing are considered __________.
A bat's wing and a bird's wing are analogous structures, as the development of these structures does not share an evolutionary history. The common ancestor of bats and birds did not have wings, therefore these traits arose independently. Therefore, they are not homologous, but represent convergent evolution, as similar traits arose from different lineages due to environmental pressures.
Compare your answer with the correct one above
Which of the following does not contribute to evolution?
Mutation, migration, natural selection, and genetic drift all change the presence and proportion of alleles in a given population, contributing to evolution. An unchanging environment would not contribute to changes in alleles and, therefore, does not contribute to evolution.
Compare your answer with the correct one above
Which of the following is an example of founder effect?
The founder effect is when genetic variability is lost due to a small number of individuals from a larger population forming a new population. The smaller population only breeds with each other and is not genetically representative of the larger group from which it was founded. Thus, the humans on a deserted island are an example of this. The hurricane might be an example of a population bottle neck and the breeder might be causing a population bottleneck by only breeding certain dogs, but the humans are a better example of the deliberate formation of a new breeding population.
Compare your answer with the correct one above
A farmer has 1000 chickens. A disease is introduced into the population that infects almost all of the chickens. The farmer loses 500 chickens to this disease. The chickens that were infected but didn't die produce fewer eggs than the chickens that were never sick, so generations later, there are more chickens that are immune to the disease than chickens who can be infected with the disease. A few generations of chickens later, the genetic diversity of the chickens is drastically reduced. What evolutionary processes are at play?
We see natural selection because those chickens that are entirely immune to the disease produce more offspring than those chickens who were infected but survive. The gene(s) that offers protection against contracting the disease is retained at a greater rate than the gene(s) that protects the chicken from dying of the disease. If the genetic diversity of the population is reduced generations later, this suggests that the chickens experienced a population bottleneck when the population number dropped to half of its original number.
Compare your answer with the correct one above
A new animal has been discovered in the rainforest. It is very similar in appearance to a known species, and has similar anatomy and dietary patterns; however, it cannot mate with the known species to produce viable offspring.
Given only the above information, which of the following statements is correct?
In order for animals to belong to the same species, they must, by definition, be able to mate with one another to produce viable offspring. The question stem says that these two animals cannot mate to produce viable offspring; therefore, they cannot belong to the same species. Since they cannot belong to the same species, they cannot "represent closely related variants of the same species," either. Although they are not the same species, the information about their similar anatomy and diet suggests that they likely evolved from a common ancestor, making the answer choice "The two animals are adapted to live in completely different environments" also incorrect.
Compare your answer with the correct one above
Which of the following changes is most likely to increase the evolutionary fitness of an organism?
An organism's evolutionary fitness is defined by the number of offspring that it produces. Mutations that increase the number of offspring that an organism can have will, by definition, increase its evolutionary fitness. Evolutionary fitness is not defined by strength, size, or habitat. While it is theoretically possible that each of the wrong answers might increase the fitness of an organism in the right circumstances, none of the wrong answers are guaranteed to increase the number of offspring produced by the organism.
Compare your answer with the correct one above