Mutation and the genetic recombination in sexually reproducing organisms.
Natural and Artificial Selection
Meiosis is the process of dividing a diploid cell into haploid cells. The main results of meiosis are four haploid cells. Genetically, these cells differ from the diploid cell and from each other.
Sexual reproduction
The main function of nucleic acids is to store and transmit genetic information and use that information to direct the synthesis of new protein.
The main function of nucleic acids is to store and transmit genetic information and use that information to direct the synthesis of new protein.
The main source of genetic variation is a large population with a large gene pool.
Natural and Artificial Selection
The two main sources of genetic variation are sexual reproduction, and mutation. Sexual reproduction is more common.
The two main sources of genetic variation are gene shuffling and mutations. A mutation is a process wherein the structure of a gene is altered.
mutations, recombination, random pairing of gametes
Mutation and sexual recombination.
Without variation natural selection would have nothing to select from that would confer survivability and reproductive success. on the organisms being selected against the organisms conspecifics and the immediate environment. Mutation and sexual recombination provide the main sources of this variation that is needed to make selection work. Mutation is the variation presented that causes the real adaptive change that can lead to speciation.
In humans? Independent assortment and sexual reproduction
Genetic variation, variation in alleles of genes, occurs both within and among populations. Genetic variation is important because it provides the "raw material" for natural selection.
inherited - from you parents or grandparents and so on. enviromental - from your environment
Crossing over of choromosomes and Mutation in cells. The law of independent assortment help as well.
Genetic mutation and variation are the main drivers of phenotype characteristic differences among species. The organisms in a population that are better suited to survive and reproduce, survive and reproduce (propagate) more than the organisms that are less suited. Add to that sexual selection and you get a wide variety of species that seem to have been designed but were sculpted by blind processes. The process of genetic mutation and variation is not a hypothesis but a scientific theory that is based on observable facts and evidence.