Organisms can have positive or negative impacts on the ecosystem they live in. the cane toad, or rhinella marina, was introduced to the hawaiian islands in 1932 by sugar cane farmers. farmers released the toads in their crops to control pests that were damaging the sugar cane. the cane toad has few natural predators, as it secretes a poisonous toxin from its skin that deters larger organisms from eating it. as a result, the cane toad population thrived and grew to number hundreds of thousands by 1935.

Dna is always read in the whereas rna is read in .

In each transformation of energy , some energy what?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.