Evolution and humans: Earth's environmental role (Evolution)

by David Turell @, Wednesday, May 31, 2017, 01:03 (1951 days ago) @ dhw

dhw: I always respond the way I do because you always make the same comment: any confirmation of evolutionary processes confirms your view that God uses evolutionary processes! If you stop making that comment, I will stop responding to it.

Since you know my view, I will stop, but I really make those statements for the lurkers who may be following us.

DAVID: As for energy, I find your view of the balance of nature supplying energy entirely backward as I think the author demonstrates.

dhw: That is YOUR view. You wrote that the balance of nature was the source of energy! The source means that the “balance” is the supplier! No, I suggest that energy supply is what determines the balance of nature, as I think the author demonstrates.

You are correct. It works in both directions. More energy means more diversity can be supported, but I view it as still bound up in a working balance of nature which must remain balanced:


"First, increasing the types of energy sources available to life has led to a far more complex biosphere. Although only geochemical energy and sunlight can power the de novo transformation of inorganic carbon into living tissue, the complexity of the current biosphere rests on multiple levels of energy use.


"The step-wise diversification of the biosphere has, in turn, led to an expansion of possible niches, from more complex microbial mats to old shells and abandoned burrows. At the same time, the capacity of life to impact the planetary environment—and thereby the environment in which future life will evolve—has expanded dramatically with each epoch.


"Because the construction of the biosphere has depended on these energy expansions, the vanishing of an energy source, even temporarily, could cause a corresponding contraction in the biosphere....one factor in the mass extinction at the end of the Cretaceous may have been dust ejected by the Chicxulub asteroid impact, which may have blocked out the sun long enough to cause a global collapse in photosynthesis.


"—the Great Oxidation Event and the emergence of mobile animals—also coincide with expansions in the kinds of energy sources available to, and consumed by, living beings. The Great Oxidation shifted the prevailing chemistry of the atmosphere and upper ocean and made oxygen gas abundant. The emergence of life forms that eat one another transformed the nature of ecosystems, and introduced a powerful new set of evolutionary interactions, thus accelerating the pace of macroevolutionary change."

Comment: I would say the balance of nature making so much food available allowed the acceleration of evolution, but did not require it. Same refrain.


DAVID: And I do not find improvement drive as equivalent to a complexity drive. Do not conflate them.

dhw: No, they are not the same, but each of them explains why speciation took place although it was not required, and so I put them together as alternatives. Perhaps I should use “or”.


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