Question

The first organisms on Earth were very small, but now when you look around you see many large organisms. Which of the following is the best explanation for this observation?

A. Organisms got larger because they needed to be larger in order to use resources more efficiently.
B. Evolution tends toward larger and larger organisms.
C. There were many steps necessary to go from small cells to large organisms.
D. The goal of evolution is to produce the largest organisms possible.

Answer 1

The correct answer is option a. Organisms got larger because they needed to be larger in order to use resources more efficiently.

Step-by-step explanation:

The best explanation for the observation that larger organisms exist today compared to the first organisms on Earth is option A: Organisms got larger because they needed to be larger in order to use resources more efficiently.

As organisms evolved and became more complex, they needed larger body sizes to support specialized organ systems that are more efficient in utilizing resources. For example, circulatory systems bring nutrients and remove waste, while respiratory systems provide oxygen for the cells and remove carbon dioxide from them. The development of larger organisms allowed for further specialization and efficient control of body functions.

This process involved many steps, and it was not the goal of evolution to produce the largest organisms possible. Instead, evolution favored adaptations that promoted survival and reproductive success in changing environments.