Changes in Organisms over Time Using fossil evidence, scientists can learn how organisms have changed over long periods of time. The chart shows information about how traits of ancestors of the modern horse have changed.

Question

Question
Use the graph to answer the question.

Select two statements that would best explain the change in horses’ body mass over millions of years.

(1 point)
Responses

There was decreased food availability.
There was decreased food availability.

Horses with larger body masses were more likely to survive and reproduce.
Horses with larger body masses were more likely to survive and reproduce.

Horses with larger body masses were less likely to survive and reproduce.
Horses with larger body masses were less likely to survive and reproduce.

There was increased food availability.
There was increased food availability.

Large body mass occurred in individuals as they became adults

Answer 1

The two statements that would best explain the change in horses' body mass over millions of years are:

1. Horses with larger body masses were more likely to survive and reproduce.
2. There was increased food availability.

These statements suggest that an increase in body mass may have provided a survival advantage in a changing environment, along with ample food resources supporting larger body sizes.