DNA, genes, proteins
When comparing species genetically, be clear on what you mean.
There are three ways to compare:
how many genes are shared between two species
how similar are the DNA sequences of those shared genes
or how similar are the total genomes (the least meaningful since only 2 to 3 percent
of the total DNA is devoted to functional genes)
All vertebrates share most of their genes, but there is a wide range of differences in the DNA sequences in those shared genes.
For instance, humans and mice share 95 to 98 percent of their genes, but the similarity of the DNA sequence within those genes is about 80 percent.
The chimp and human share 95 to 98 percent of their genes, but the DNA sequence within shared genes is 95 to 98 percent the same.
Full names of genes are usually lowercased and roman:
the tabby gene in cats
Symbols for genes are italicized:
a gene called CKR5
the symbol for the tabby gene is T
Symbols for proteins are in roman:
the gene for the protein BMP4