The tree of life
Charles Darwin famously delineated a branching ‘tree of life’, and in this spirit we present the diagrams below to give you an overview of relationships between all the forms of life mentioned on the website. There is also a ‘Tree of life’ link in the footer of every page on the site, so you can easily return to check how the organisms you are reading about are related. It should be remembered that research on the tree of life is ongoing and that the final verdict on the placement of several groups is still under intense discussion. We have provided a simple consensus of present knowledge, with awareness that the positions of some groups are not fully resolved.
Not surprisingly even professional biologists are unlikely to be familiar with every group mentioned here, but in all cases they reveal important examples of convergence. Finally, whilst the groups depicted are agreed to be genuinely ‘monophyletic’ (that is they share a single common ancestor), it should be noted that lateral transfer of genetic material between branches of the metaphorical ‘tree’ frequently occurs at some levels.