Both Charles Darwin and Alfred Russel Wallace acknowledged the influence of the economist Thomas Malthus in the development of their ideas about natural selection. Specifically, Malthus's ideas about geometric population growth implied that:

Explanation:

Malthus's ideas about geometric population growth implied that: resources in every generation would be limited, therefore individuals in every generation would have to compete for those resources

resources in every generation would be limited, therefore individuals in every generation would   have to compete for those resources.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg