Natural selection could not occur without?

Question

A.) genetic variability in species
B.) interspecific competition
C.) environmental changes
D.) the ozone layer

Answer 1

I will say (a) genetic variability. This means the members of the same species have some differences. Whatever does the selection - environment, competition for food, predators - the differences could determine who more likely succeeds, lives to pass on those differences.

The other answers?
(b) Inter- means between; intra- means among, inside; "interspecific" (interspecies?) means competing with other species. But competition could be more likely within members of the same species, for the same food or females or getting away from the same predators.
(c) Environmental changes could be one of several factors that cause selection; (i.e.,colder, the furry ones survive) but it could be something different that has nothing to do with the weather, like a new predator.
(d) The ozone layer protects against harmful UV which can hurt or kill some species, and perhaps cause mutations in some. I.e. humans with darker skin survive with less skin cancer in high-UV environments. But it is not something which is the essential element to natural selection.

Answer 2

All of the above... Well, A, B & C...

(a) If there were no genetic variability there would be no mutations for nature to select (all species differences are based on mutations that bred true)

(b) If there were no competition (wether preditor/prey or competition for the same food) there would be no reason to diversify. Everything would remain the same since there was no reason to try to be better than anyone else

(c) environmental changes push the mutations and genetic differences to select new mutations as beneficial to the species. Animals who do not mutate (adapt) will no longer survive

Answer 3

C.)
Natural selection acts on the phenotype. The phenotype is determined by an individual's genetic make-up, known as its genotype, as well as the environment in which the organism lives, and the interactions between genes and between genes and the environment. Often, natural selection acts on specific traits of an individual, and the terms phenotype and genotype are sometimes used narrowly to indicate these specific traits. Most traits are influenced by the interactions of many genes, but some traits are governed by only a single gene in patterns known as Mendelian inheritance. Variations in one of many genes contributing to a trait may have only a small effect on the phenotype, producing a continuum of possible phenotypic values; the study of such complex inheritance patterns is called quantitative genetics

Answer 4

The vibrant imaginations of evolution-preaching pseudo-scientists.

Oh... and a lot of NSF grant money spent on "proving" this tautology:

Answer 5

c

Answer 6

B.