Oh, I do love this! When you do careful examination of DNA you find out where animals – and all living things – fit in the Tree of Life. You’ll also find the old tree we learnt with ‘humans’ proudly at the top as the crowning glory, was done before we knew much about DNA.
And it is sometimes very surprising. For example, when Charles Sibley and Jon Ahlquist started classifying birds according to their genetic code, they found this bird on the right:
. . is more closely related to an Australian crow than it is to the bird on the left! They look and behave the same due to convergent evolution. Same with the next two: Look the same; only distantly related in the bird world:
So for decades and centuries ornithologists knew the two birds were related as they had the same beaks and the same habits, so you can imagine some of them were none too pleased to be told in 1988 by relative newbies that what they thought – heck, what they ‘knew’ – was wrong!
Just like zoologists had known for a long time that mammals in Australia had evolved to fit various niches. These two are more closely related to each other than they are to dogs or squirrels:
And so we come to the even more recent discovery: That cockroaches are crustaceans.
Not only should we eat insects as a better way of producing protein, we should charge higher prices for them! The menu at my new restaurant will feature in future – Cockroach Thermidor SQ