Thanks very much chaps, I'm glad you all enjoyed it. It was cobbled together from numerous internet sites and research papers freely available online, most of which I quoted in the references. The Tree of Life pages were particularly valuable
I'd also like to thank Steve for taking the time for checking the article through and correcting me where I was going wrong. Cheers Steve!
I'm not too sure about your query there Monty, that sentence was one of Steves corrections. I'll try and find out for you.