Which of these is an example of gradualism?

Question

Which of these is an example of gradualism?

1 the variation of tortoise shells that evolved as tortoises lived on different islands with different habitats

2 slow evolution of whales from a four legged land mammal over millions of years

3 rapid speciation following a catastrophic event

4 separate evolution of flight in birds and bats

Answer 1

2 slow evolution of whales from a four legged land mammal over millions of years

Answer 2

Option 2, the slow evolution of whales from a four-legged land mammal over millions of years, is an example of gradualism. Gradualism refers to the concept in evolutionary biology where species gradually change over long periods of time, accumulating small variations and adaptations that eventually result in significant changes or the emergence of new species. In the case of whales, their transition from land-dwelling mammals to fully aquatic animals occurred gradually, with numerous intermediary stages and adaptations along the way.