Although we may not yet have definitive answers as to how cats became domesticated (and there are cat lovers who will argue that they never have), we do know a great deal about their genetics.

With little in the way of noteworthy evolution, genetically we know that today's cat and its close cousins have 38 chromosomes. Like most mammals, cats are diploid, meaning cells of that name have two copies of each chromosome, one from each parent. Diploid cells in people have 46 chromosomes (our egg and sperm cells {haploid gametes} have half that amount - 23 chromosomes). Cats have approximately 20,000 genes. In comparison, in May of 2009, scientists announced a possible 40,590 genes in human genome.

We humans share many of the 250 genetic disorders identified in cats; other mutations are unique to our feline pets. All cats, big and small, wild and tame, from the African lion to the kitten in your lap, share a specific mutant chemosensor in their taste buds. This mutation prevents them from tasting sweetness. It is not disdain when your cat refuses your offer of a sweet tidbit — it just may not be very appealing when the sweet taste is absent.

As in human beings, cats may have congenital deafness, (a heritable condition present at birth). Such deafness is common in blue-eyed white cats of most breeds. Scientists hope that by studying the defect in cats, they made learn which genes are responsible for the same condition in people.

The similarities in our genetics led scientists to create The Cat Genome Project. This is being conducted by the Laboratory of Genomic Diversity at the U.S. National Cancer Institute's Frederick Cancer Research and Development Center in Frederick, Maryland. This work will establish the animal model for many human heritable conditions and infectious diseases and will aid our understanding how mammals evolved. Project members published an initial draft of the genome of Cinnamon, an Abyssinian, in 2007. Their work has already led to the identification of numerous cat disease genes and led to successful ‘genetic fingerprinting’ of cats, valuable in forensics.

Coat genetics cause the extensive variety of coat patterns in cats. Hair color and pattern are created by the interaction of several genes. In different combinations, this interaction causes different color, pattern and growth traits (genetically caused traits are called phenotypes).

As genome research continues, we learn some amazing things about specific genes. An inactive copy of the gene for fibroblast growth factor 5 causes long hair; an active copy creates short hair. Some mutations are temperature sensitive: In Burmese cats, the mutant form of melanin (dark pigment) is only active at low temperatures, so the cat has dark color only on the cooler body parts — ears, tail and paws. The enzyme tyrosinase produces this mutation; an inactive version of the same gene creates albino cats (albinos of any species lack all pigmentation).