Questions: Students learn that although mammals have existed for about 200 million years, they have mostly remained a around 65 million years ago, and mammals diversified in less than 20 million years. Based on the information, what conclusion can be made about how asteroids colliding with Earth shape evolution? It created the group of animals called mammals. It helped the dinosaurs to evolve into mammals. It caused the conditions for new species to evolve. It eliminated all the four-legged species from Earth.

The answer is the third one: It caused the conditions for new species to evolve.

Explanation for each option:

• It created the group of animals called mammals.
  This option is incorrect because mammals existed for about 200 million years, which means they were already present before the asteroid impact that occurred around 65 million years ago.

• It helped the dinosaurs to evolve into mammals.
  This option is incorrect because dinosaurs did not evolve into mammals. Mammals and dinosaurs are distinct groups that coexisted for a long time. The extinction event that affected the dinosaurs allowed mammals to diversify, but it did not cause dinosaurs to evolve into mammals.

• It caused the conditions for new species to evolve.
  This option is correct. The asteroid impact around 65 million years ago is believed to have caused a mass extinction event that eliminated many species, including most dinosaurs. This event created ecological niches and conditions that allowed mammals and other groups to diversify and evolve into new species.

• It eliminated all the four-legged species from Earth.
  This option is incorrect because not all four-legged species were eliminated. While many species, including most dinosaurs, went extinct, mammals and other four-legged species survived and diversified after the extinction event.

In summary, the asteroid impact created conditions that allowed for the evolution and diversification of new species, particularly mammals.