Brachyury and ParaHox genes also shed light on animal physiology . They also indicate why some animals only have a ' transient ' anus . Study also shows how some animals have very similar digestive abilities to humans , even though they are very different species .
Brachyury and ParaHox genes could shed light on anus evolution . They may indicate why some creatures only have a 'transient ' anus . Study also reveals how some creatures have very similar digestive systems to humans , even though they are very different species .