Word Origin and History for mesopotamian. ancient name for the land that lies between the Tigris and Euphrates rivers (in modern Iraq), from Greek mesopotamia (khora), literally a country between two rivers, from fem. of mesopotamos, from mesos middle (see medial (adj.)) + potamos river (see potamo-).
Monogenic forms, caused by a single mutation in a dominantly or recessively inherited gene, are well-established, albeit relatively rare types of PD. They collectively account for about 30% of the familial and 3%â5% of the sporadic cases.
Coat color and pattern is a polygenic trait, meaning it is controlled by more than one gene or gene complex.A dog with the gene for black color expression may also have the gene for suppression of black and so have a red or yellow coat. Polygenic traits are [characteristics of organisms that are] â¦  influenced by several genes.    So multiple alleles are more than two alleles for one trait, and  polygenic traits are one trait that is influenced by mulitple  genes.