Want this question answered?
sexual reproduction and mutations provide variation among species
Charles Darwin wrote a book called On the Origin of Species, in which he explained his conclusions that 1) modern species derived from ancestors they share with other species, and 2) that the driving mechanisms behind this development is reproductive variation and natural selection.
There is no separate theory of evolution for humans. Human evolution is the theory of evolution applied to humans. Evolutionary theory states that modern lifeforms, including humans, derive from common ancestors through a process of reproductive variation and natural selection.
This question can not be answered without more information.
Evolution is a slow, slow process which enacts itself over many generations. Species evolve to adapt to environments and to survive, which makes evolution the mechanism through which "survival of the fittest" succeeds as a natural order.
sexual reproduction and mutations provide variation among species
Charles Darwin wrote a book called On the Origin of Species, in which he explained his conclusions that 1) modern species derived from ancestors they share with other species, and 2) that the driving mechanisms behind this development is reproductive variation and natural selection.
The finches of the Galapagos Islands provided Charles Darwin with the inspiration for his Theory of Evolution. They provided the basis of modern biology. The differences found between species in such a small place are important for the study of Bioogy.
how variations occur within a species
There is no separate theory of evolution for humans. Human evolution is the theory of evolution applied to humans. Evolutionary theory states that modern lifeforms, including humans, derive from common ancestors through a process of reproductive variation and natural selection.
That no species is stable, and that all species become extinct in time. That includes us.
This question can not be answered without more information.
Evolution is a slow, slow process which enacts itself over many generations. Species evolve to adapt to environments and to survive, which makes evolution the mechanism through which "survival of the fittest" succeeds as a natural order.
Creationism says that God or gods created the Earth and all life upon it. Prior to modern science, most religions taught some variation of this idea. The Theory of Evolution argues that the "design" of life developed gradually over time, as a result of environmental pressure and competition between species. Currently, all known scientific evidence supports the Theory of Evolution, and no evidence for Creationism has ever been found. Many religious people accept the Theory of Evolution, but believe that God foresaw the appearance of modern humans.
It explains that modern humans are the result of a long-going and ongoing process of reproductive variation and differential reproductive success, punctuated by divergence between subpopulations and subsequent speciation events.
Without beneficial mutations leading to beneficial variation there would be no natural selection on the individual organism, outside of sexual recombination, which would mean no change in allele frequency over time leading to no evolution. Fortunately, that is never the case in nature and mutations lead to variation and adaptive change in the organisms under selection pressure.
It explains that modern humans are the result of a long-going and ongoing process of reproductive variation and differential reproductive success, punctuated by divergence between subpopulations and subsequent speciation events.