Answer:
The answer is:
D. the radiation of herbivores such as grazing animals
Explanation:
Oligocene and Miocene Epochs:
- The Oligocene epoch is characterized by temperate and subtropical climatic conditions which favored the expansion of grasses and reduced forest cover.
- The Miocene epoch, which succeeded the Oligocene era, is attributed to changes in global circulation due to global warming of the climate followed by global cooling towards the end.
The Oligocence and Miocene epoch are both attributed to the expansion of grasslands and savannah. Both eras marked rapid and drastic evolutionary changes in grazing mammals and herbivores. Diverse groups of grazing mammals lived throughout these eras. For example, the largest herbivore and land mammal of all time, <em>Indricotherium</em> (a sort of giant hornless rhinoceros), was present in the Oligocene era.
Similarly, the Oligocene era in North America favored the rapid radiation of primitive horses.
The genes in a population give forth the genetic variability across a population (genotypes). In addition, occasional mutations of these genes in a population increase this genetic variability. Hovever, natural selection only favours reproduction of individuals with genes that are favourable in the environment/habitat. Therefore, natural selection has no foresight but is rather pegged on being an ‘opportunistic’ process.
Answer:
A
Explanation:
The correct answer would be that <u>the availability of food resources for black mice and brown mice will decrease.</u>
<em>Since the food requirements of the black mice are the same as that of the invasive brown mice, the available food supply that used to be only for the black mice would now be shared by the two strains of mice. Hence, the available food for the two groups of mice will naturally decrease.</em>
There is no sufficient information to conclude that the population of tan mice will decrease, hence, option B is incorrect.
The black mice and tan mice have different food requirements going by the information available in the illustration, hence, both cannot compete for food resources. Option C is, therefore, incorrect. In the same vein, option D is incorrect because the tan mice have different food requirements from the brown mice.
<u>The only correct option is A.</u>
D-As stress levels increase, job efficiency increases is the correct answer.
