Evolution: where did cyanobacteria come from? (Introduction)

by David Turell , Tuesday, June 20, 2017, 15:07 (2714 days ago) @ dhw

DAVID: You are correct. I had forgotten that bipedalism skeletal changes appear before Lucy's decedents fully left the trees. But in these examples the changes are in areas of living as environmental change, not Earth's environmental change as in oxygen concentrations. Area change requires pre-planning. As for your word 'trigger' I don't like any more than 'initiate' both of which imply causation, but I now know you have a different view of he meaning of those words. I prefer that changes 'allow'.

dhw: If you believe in common descent, clearly all innovations must occur in individual organisms, and so speciation will take place in individual locations (though there could be several locations at the same time). Are you now saying that, for example, if there was an environmental change that was confined to parts of Africa, God would have anticipated the change and restructured beforehand all the organisms he wanted to speciate? In any case I don’t see why, in your scenario, area change requires pre-planning and global change doesn’t.

You are correct that innovations occur in species individuals but only current humans are all over the Earth. I was noting again whales from land to water (area) and Cambrians (same place, more oxygen) as a different kind of initiating due to change in environment, but in the same area. God speciates either way.