You’d be forgiven for thinking that the banana is about as far away from a human being as you can get. Yet we actually share 60 per cent of the same DNA. In fact, if you could peer through the lens of a microscope at the genes that make up human DNA, you would be astonished to discover how much of it is present in the animal kingdom. For example, we share 18 per cent of our DNA with yeast, 47 per cent with fruit flies, 65 per cent with chickens and 90 per cent with cats.
Scientists believe that all animals, plants and fungi have evolved from a single ancestor that lived around a billion years ago. So why don’t we all multiply in warm, moist environments, lay eggs and purr? Because the genes we share with these species have different functions in the human body.
While our biology may denote which species we belong to, some anthropologists would claim that morality is what sets us apart as humans, while the philosopher Aristotle said that we are separated from animals by our rationality.