CHOOSE THE BEST ANSWERS Over the last 500 years, 34 amphibia…

CHOOSE THE BEST ANSWERS Over the last 500 years, 34 amphibian species have gone extinct out of 6,400 known amphibian species. The background extinction rate is the rate at which species go extinct during the interludes between mass extinction events. On average, the background extinction rate for amphibians is 2 extinctions per 10,000 species per 100 years. Based on the background extinction rate, how many amphibians would be expected to have gone extinct over the last 500 years? How does the observed number of extinctions compare to the expected number of extinctions?

CHOOSE THE BEST ANSWER In a population of frogs, an allele t…

CHOOSE THE BEST ANSWER In a population of frogs, an allele that increases mating success also causes an increased likelihood of developing a fatal skin infection later in life. Given this information, why doesn’t natural selection eliminate this harmful infection from the population?