The range of cattle egrets has expanded between 1937 and today. how would an ecologist likely explain the expansion of the cattle egret?
a) the first egrets to colonize south america evolved into a new species capable of competing with the native species of herons and egrets
b) a habitat left unoccupied by native herons and egrets met the biotic and abiotic requirements of the cattle egret transplants and their descendants
c) there are no predators for cattle egrets in the new world, so they continue to expand their range

Which element provides strength to the exoskeleton of clams and oysters

Read the following scenario to answer the following question. over the past 60 years, many amphibian species have experienced significant population declines, and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. when most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that a. the founder effect becomes increasingly important b. microevolution no longer occurs c. gene flow between populations is reduced d. artificial selection becomes a greater factor in microevolution

What is the difference between how ionic and covalent bonds form