More about how evolution works: multicellularity (Evolution)

by dhw, Tuesday, October 25, 2016, 12:27 (2738 days ago) @ David Turell

DAVID: Multicellularity is very complex and not an improvement on the easy livability present in bacteria. Again, why bother?

dhw: Endosymbiosis is a process that is beneficial to both organisms. Benefit = improvement in my book. As environments changed, new challenges and opportunities arose. The challenges required adaptation, but the opportunities enabled improvement. I’m surprised that you think “livability” is the only criterion for improvement.

DAVID: 'Opportunities enabled improvement' is a strange phrase.

It would not have been possible for innovations to take place if the environment had been unfavourable for them. An increase in oxygen may have created the opportunity for new organisms to come into being to exploit the environment in new ways. That is why I link innovation and improvement to opportunities offered by the environment.

DAVID: 'Challanges required adaptation' is correct. It demands improvement or extinction. Bacteria weren't challenged. They solve all problems and survive, need no improvement. Why multicellularity? Can't get to us any other way. Today's bush of life is exceedingly complex. Advancing evolution requires complexity beyond bacteria.

I can only comment disjointedly on this disjointed paragraph. What demands improvement or extinction? Is this a misprint? Why do you say bacteria weren’t challenged? They have met every challenge by adapting, but yes indeed they are still bacteria. Why multicellularity? You can’t get to the duckbilled platypus and thousands of other species extant and extinct any other way. So why just “us”? Multicellularity by definition is more complex than unicellularity, and of course evolution would not have advanced without it.