Question

vanishing insects: why does biodiversity matter? although they must often seem abundant to us, insect populations globally are in trouble. more than 40% of insect species are declining and a third are endangered. just as concerning as this loss of diversity is the loss of insect biomass, which is falling by an estimated 2.5% a year. the cascading effect of insect loss threatens food chains globally. the causes are many and cumulative and include climate change, use of pesticides, and habitat loss. a pair of blue tits may collect 100 insects a day to feed one chick. the winter moth caterpillar is an invasive species in the us but provides abundant food for birds. the larvae of green lacewings feed on aphids and other soft - bodied insect pests. five crucial insect roles insects have a central role in the ecosystem services humans rely on for survival. the decline in the numbers and diversity of insects has serious consequences for a sustainable future. 1: providers insects are part of almost all food chains as prey for a wide range of other animals, including birds, bats, amphibians, and fish. recent declines in many bird populations have been linked to scarcity of insect prey. species at higher trophic levels may decline in numbers and diversity. 2: pest controllers predatory insects play a critical role in controlling the pest insects that threaten crops. they help to reduce pest control costs and increase yields, saving billions of dollars every year. pests may increase, damaging crops, forests, and pesticide use may increase. 3. using 2. (a) describe the primary cause of the current lack of genetic diversity in modern sea otter populations: (b) describe the likely reason for the low genetic diversity in the california population: (c) how might this be related to more recent declines in the california population:

Explanation:

(a) The primary cause of the current lack of genetic diversity in modern sea - otter populations is likely due to a historical bottleneck event. In the past, sea - otters were heavily hunted for their fur, which drastically reduced their population size. When a population experiences a significant reduction in size, the genetic variation also decreases as only a subset of the original genes are present in the remaining individuals.
(b) In the California population, the low genetic diversity is probably a result of the same historical over - hunting. Additionally, the California population may have been more isolated geographically, which further limits gene flow from other sea - otter populations. This isolation can prevent the introduction of new genetic material, maintaining low genetic diversity.
(c) The low genetic diversity in the California population can be related to more recent declines. With low genetic diversity, the population has less genetic variation to adapt to environmental changes such as disease outbreaks, changes in food availability, or pollution. A lack of genetic variation means that there may be fewer individuals with traits that can help them survive these challenges, making the population more vulnerable and more likely to experience declines.

Answer:

(a) Historical bottleneck due to over - hunting for fur.
(b) Historical over - hunting and geographical isolation limiting gene flow.
(c) Low genetic diversity makes the population less adaptable to environmental changes, increasing vulnerability to declines.