Dear PF Forum, Lately I've been watching this channel https://www.youtube.com/user/cassiopeiaproject It's a very good science channel And I've been wondering about this one thing. The origin of animal At first, "life" couldn't do photosynthesys (what ever that we call "life") And at 3.4 billions years later, there life could do photosynthesys. 1. Did animals evolve from these cells? And after that there were two distinct groups. Bacteria and Archaea. 2. Did bacteria can do photosynthesys? Some of them can do I think. And from archaea there are two distcint groups. Animal and Fungi Plants. So, at first there were some cells that can do photosynthesys on earth about three and a half billions years ago. And later, from these cells, some of them lose the ability to do photosynthesys, such as animal and fungi? Were plants the ancestor of animal (and fungi) ancestor's? Thanks for the enlightment.