In ostriches, there are 2 types: ones that run fast and those that run slowly. The fast birds can reach up to 40 miles an hour. Jackals love to eat ostrich, and they can reach speeds of up to 35-40 miles per hour. A flock of ostrich will lay ~ 10 eggs (each mother only lays 1), but many rodents break into the eggs and eat the fetus before they hatch.
What ostrich will natural selection select for and against?

Natural selection will select the type of ostriches that can run up to 40 mph.

Explanation:

According to the theory of natural selection, organisms with favorable traits following their environment are more likely to reproduce. In doing so, they pass on the better traits to their next generation for the survival of their species.

This process allows organisms to adapt to their environment. And the survival of species is assured.

Here, the type of ostriches that run slow probably fall prey to the jackals. To maintain survival, the ostriches reproduce and lay eggs. If out of almost a dozen eggs, one or two are left to hatch than the chances of their survival will greatly be affected if the hatching ostriches are of the slow-running type.

Therefore, natural selection may stay in favor of fast-running ostriches to hatch.

For: the fast ostrich

against: the slow ostrich