D4.1 天擇（生態系）：练习题

A population of rabbits lives in an environment with both very dark volcanic rocks and very light sandy patches. Rabbits with medium brown fur are easily spotted by predators in both habitats, while very dark or very light rabbits are camouflaged. This scenario is most likely to lead to what type of natural selection?

The human eye is often cited as an example of a complex, highly evolved organ. However, it exhibits a 'blind spot' due to the optic nerve passing through the retina, creating an area insensitive to light. From an evolutionary perspective, this imperfection is best understood as:

Which statement accurately describes a key principle of natural selection?

A small population of a specific plant species is established on a newly formed volcanic island by a few seeds carried by wind. This initial population exhibits a much lower genetic diversity than the mainland source population. Over generations, despite significant environmental pressure, some alleles that were rare in the mainland population become common on the island, while some common mainland alleles are absent. This phenomenon is best explained by:

Explain how convergent evolution can lead to similar phenotypic traits in distantly related species inhabiting similar ecological niches, providing a specific example to illustrate this concept.

A population of the grass species Agrostis tenuis is found growing in an area adjacent to an old copper mine. While most of the field has normal soil, the area closest to the mine is heavily contaminated with copper ions. It is observed that only the grass growing on the contaminated soil exhibits copper tolerance.

(a) Using the principles of natural selection, describe how the population of copper-tolerant grass developed on the contaminated soil. (3 points)
(b) Explain why the copper-tolerant plants, despite being able to survive on normal soil, are rarely found in the uncontaminated parts of the field. (2 points)