Question

adaptive radiation 2
which of the following scenarios is explained by adaptive radiation?
multiple choice
the average running speed of a cheetah increases each generation due to the gazelles getting faster.
the fur of an arctic fox changes from brown to white in the winter when there is snow on the ground.
the color pattern of the moths living in the woods of england become darker as the levels of pollution increase during the industrial revolution
a plant species arrives on an island and gives rise to an extremely diverse clade of trees, shrubs, and other species at a relatively rapid pace.

Explanation:

Adaptive radiation is the rapid diversification of a single ancestral species into many descendant species, each adapted to different ecological niches. Let's analyze each option:

• First option: Cheetah speed increase due to gazelles getting faster is co - evolution (predator - prey), not adaptive radiation.
• Second option: Arctic fox fur color change is seasonal adaptation (phenotypic plasticity or maybe natural selection for camouflage), not radiation (no new species).
• Third option: Moth color change (industrial melanism) is natural selection within a species, not radiation.
• Fourth option: A plant species arrives on an island and gives rise to a diverse clade of trees, shrubs, etc. This is a single species (ancestor) rapidly diversifying into many species (descendants) adapted to different island niches, which fits adaptive radiation.

Answer:

The option: "A plant species arrives on an island and gives rise to an extremely diverse clade of trees, shrubs, and other species at a relatively rapid pace."