a Drought hits the habitat of a semi-aquatic bird population. All ponds dry up, and fish populations decline. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, white short-legged birds eat insects. The drought has little effect on insect populations.
What is the main selective pressure in this scenario?
**leg length
**insect population
**fish population
**drought
In this scenario, the main selective pressure is the drought. A selective pressure refers to an environmental factor, such as a change in habitat or availability of resources, that influences the survival and reproduction of a particular species or population.
During a drought, the ponds dry up, resulting in a decline in the fish population. This reduction in fish availability adversely affects the long-legged birds that primarily eat fish. On the other hand, the drought has little effect on the insect population, which is the main food source for the short-legged birds.
As a result, the main selective pressure in this scenario is the drought, as it significantly impacts the availability of food resources for the bird population.