The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that
A) a larger volume-to-surface area ratio is beneficial to all mammals.
B) an unseen guiding force is at work.
C) evolution always tends toward increased complexity or increased size.
D) in particular environments, similar adaptations can be beneficial in more than one species.

Question

Quizplus · Accepted Answer

Evolutionary trends like increasing body sizes in horse species indicate that in particular environments, similar adaptations can be beneficial in more than one species. This is supported by the fact that horses evolved in different geographic regions of the world but all increased in body size over time. Therefore, it is not necessary that evolution always tends towards increased complexity or size, or that a larger volume-to-surface area ratio is beneficial to all mammals. Lastly, there is no evidence to support the idea of an unseen guiding force.

The Existence of Evolutionary Trends, Such as Increasing Body Sizes