he processby which those previously independent organisms came together to form neworganisms is called endosymbiosis. The process of endosymbiosis was first pos-tulated in the early 20 th century but verified later by Lynn Margulis, who wasalso instrumental in developing the Gaia theory with chemist James Lovelock.
for - definition - endosymbiosis - to - explainer video on Major Evolutionary Transitions - https://hyp.is/zXozbCT8EfCSIF_rc_6riQ/www.youtube.com/watch?v=VUfNEHl44hc - adjacency - major evolutionary transition - endosymbiosis