Dark grey. Dark grey horses will have a light black coat, mane and tail. Brown. Brown is a very common horse colour and sometimes it can be hard to tell if horses are brown or black. There coat, mane and tail will all be brown from a light tan colour to a dark chocolate colour.
Genetic variation is a fact that a biological system â individual and population â is different over space. It is the base of the genetic variability of different biological systems in space.Genetic variation is based on the variation in alleles of genes in a gene pool.It occurs both within and among populations, supported by individual carriers of the variant genes. Genetic variation is brought about by random mutation, which is a permanent change in the chemical structure of a gene.enetic variation is based on the variation in alleles of genes in a gene pool. It occurs both within and among populations, supported by individual carriers of the variant genes. Genetic variation is brought about by random mutation, which is a permanent change in the chemical structure of a gene.
Genetic variation refers to genetic differences both within and among populations. There may be multiple variants of any given gene in the human population (alleles), leading to polymorphism.he main cause is genetic drift, this is the effect of random changes in the gene pool. In humans, founder effect and past small population size (increasing the likelihood of genetic drift) may have had an important influence in neutral differences between populations.