The main selective pressure in this scenario is the fish population. The decline in fish populations affects the long-legged birds that rely on fish as their primary food source. Since the short-legged birds eat insects, which are stable in population, they are not directly impacted by the decline in fish. Therefore, the selective pressure comes from the availability of food resources (fish) for the long-legged birds.
Consider the following scenario:
A significant decline in fish populations occurs in the habitat of a semi-aquatic bird population. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, while short-legged birds eat insects. The insect population remains stable.
What is the main selective pressure in this scenario?
(1 point)
• insect population
• bird population
• leg length
• fish population |
1 answer