What might be the effect of a mutation in the promoter sequence of a gene

What happens is it alters the regulation of the expression of the gene. Sometime you will see a loss of function, or reduction of ability to work such as complete loss of a protien code. Or you can gain a function or to much. So it doesn't regulate what it needs well and keeps producing when it shouldn't.

Ifound this on google “aristotle (384–322 bc) in western scientific taxonomy the greek philosopher aristotle was the first to classify all living things, and some of his groups are still used today, like the vertebrates and invertebrates, which he called animals with blood and without blood.” i hope this you for what your looking for.