Genome Sizes

The genome of an organism is the complete set of genes specifying how its phenotype will develop (under a certain set of environmental conditions). In this sense, then, diploid organisms (like ourselves) contain two genomes, one inherited from our mother, the other from our father.

The table below presents a selection of representative genome sizes from the rapidly-growing list of organisms whose genomes have been sequenced.

Table of Genome Sizes

The Human and Chimpanzee Genomes

Now that the genomes of both the human [Link] and the chimpanzee have been determined, it is possible to make more direct comparisons between the two species.

The results:

  • Their genomes are 98.8% identical (between any two humans — picked at random — the figure is closer to 99.5%).
  • Comparing over 7,000 genes that occur in both species (as well as in the mouse), it turns out that slightly over 1,500 of these have evolved quite differently in the