Mass extinctions have occurred repeatedly during the course of Earth's history. One of these events occurred at the end of the Cretaceous Period, during which the dinosaurs became extinct. Mammals flourished after the dinosaurs were gone. This led to a variety of genetically diverse species. Why did the mammals suddenly start diverging into different species after the dinosaurs were gone?

Most of the predators were gone and suddenly niches were available so almost all the offspring were likely to survive and reproduce.
Once the dinosaurs were gone, the mammals started having larger numbers of offspring in each litter to fill the empty niches.
The mammals chose to move into the vacant niches the dinosaurs had occupied and change their body shapes to suit these new environments.
Mammals began mutating rapidly once the dinosaurs died out and were able to create new species based on the mutations.

Explanation:

Two of Earth's five mass extinction events -- times when more than half of the world's species died -- resulted in the survival of a low number of so-called 'weedy' species that spread their sameness across the world as the Earth recovered from these dramatic upheavals. The findings could shed light on modern high extinction rates and how biological communities may change in the future.

humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of invasive species (such as new predators and food competitors), overhunting, and other influences. explosive, unsustainable human population growth is an essential cause of the extinction crisis.

explanation:

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the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

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