Question

which change in the evolutionary history of horses is documented by the fossil record? a direct evolutionary path to modern - day horses a gradual decrease in the number of toes transition from an aquatic habitat to land a gradual decrease in body size a gradual increase in the number of toes

Explanation:

The fossil record shows that early horse ancestors had multiple toes. Over time, through evolution, there was a gradual reduction in the number of toes. For example, the earliest horse - like animals (e.g., Hyracotherium) had four toes on the front feet and three toes on the hind feet. As evolution progressed, the side toes became smaller and less functional, and modern - day horses have only one toe (the hoof, which is a highly modified single toe).

Option 1: Evolution is not a simple direct path. There are many branches and extinctions in the evolutionary tree, so a direct evolutionary path to modern - day horses is incorrect.

Option 3: Horses have always been land - dwelling animals. Their ancestors were also land - dwelling, so a transition from an aquatic habitat to land is wrong.

Option 4: The fossil record shows that horse body size generally increased over time (e.g., Hyracotherium was small, about the size of a dog, and modern horses are much larger), so a gradual decrease in body size is incorrect.

Option 5: As explained above, the number of toes decreased, not increased.

Answer:

a gradual decrease in the number of toes