2007-02-21 23:27:02 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The correct answer is selection. Doesn't matter what kind, artificial, natural or sexual, selection drives evolution.
Technically stochastic factors (factors that are purely based on random chance) such as adaptability and genetic drift don't drive evolution. They may contribute to evolution, but there is no direction, nothing is being driven.
2007-02-22 04:02:32 · answer #1 · answered by floundering penguins 5 · 0⤊ 0⤋
Mutations and sexual reproduction increase diversity by providing a richer more diverse gene pool in populations
Natural Selection increases the adaptability or inevitably causes the extinction of species by decreasing the diversity of life
"Survival of the fittest"
The answer is Diversity and Natural selection are inter-related processes or forces that drive evolution
2007-02-22 08:43:21 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Darwin suggested it was "natural selection"; that is, that nature constantly throws up new traits and characteristics and that the pressure to survive weeded out the "unfit" and passed on those traits which were favorable to survival to the offspring.
As many have noted, this means, in fact a rather circular proposition, "survivors survive", and doesn't seem to explain much.
Another possible engine is "sexual selection"; that is that mates choose such characteristics as they feel shows the "fitness" of a prospective mate, and that those characteristics are then inherited by the offspring. Whether a species survives and adapts or becomes extinct depends on the characteristics that were sexually selected.
Sexual selection explains why some species do exceedingly well, but following some environmental changes are unable to cope with new pressures and become extinct quite well.
2007-02-22 07:39:24 · answer #3 · answered by P. M 5 · 0⤊ 1⤋
Change and random chance.
The change can be geologic (climate change, movement to a new area with a different geology, isolation [cross a landbridge or ice floe that goes away]) it can be population based (that of your population, as in Darwin Finches needing to have different beaks for different foods, or change in the population of predators.) It can be internal (females start to prefer red bellies, red bellies get more common) or external (winters get longer and coniferous trees, which photosynthesize all year, survive.) It's still a matter of random change in the environment and changes in the population of critters that starts as random chance.
The driving force of evolution is that things and their environments change over time.
2007-02-22 09:39:40 · answer #4 · answered by LabGrrl 7 · 0⤊ 0⤋
Natural selection, artificial selection, gene drift [when a part of a population migrated to another location] and gene flow [when a population meets with another population of the SAME species but originates from different ecological background]. Of course, there are mutations but according to evidence, mutation contribute less to evolution as it is rather a random occurrence and the survival rate is precarious.
2007-02-22 08:40:18 · answer #5 · answered by Anonymous · 0⤊ 1⤋
Genetic mutation creates change. Environmental pressures select traits caused by mutation that improve survivability.
2007-02-22 07:30:12 · answer #6 · answered by poorcocoboiboi 6 · 0⤊ 1⤋
yes,natural selection is a good answer,but also adaptability
2007-02-22 07:30:31 · answer #7 · answered by razza 3 · 0⤊ 1⤋
"Natural selection" is surely the answer desired.
2007-02-22 07:29:22 · answer #8 · answered by Curt Monash 7 · 0⤊ 0⤋
i'd say adaptability... organisms have to evolve in order to survive
2007-02-22 07:47:57 · answer #9 · answered by dr 2 · 0⤊ 1⤋
mutation and death.
2007-02-22 10:15:58 · answer #10 · answered by Leviathan 6 · 0⤊ 0⤋