Heart-shaped ivies, sometimes called sweethearts, have a leathery look and are rarely lobed. Miniatures are slow growers and the smallest ivies. Their largest leaves are no bigger than 3/4 inches long and 1/2 inch wide; they make good terrarium subjects. An ivy plant can fall into more than one of these categories.
The second main cause of genetic variation is due to the high degree of neutrality of most mutations. Most mutations do not appear to have any selective effect one way or the other on the organism. The 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.
1. Variations of genomes between members of species, or between groups of species thriving in different parts of the world as a result of genetic mutation. 2. Genetic diversity in a population or species as a result of new gene combinations (e.g. crossing over of chromosomes), genetic mutations, genetic drift, etc. 3. Important in maintaining biodiversity among species. User Contributions / Comments: 1  Genetic variation is important in that it may provide alternative phenotypes which may respond to the environment in different ways.