New Miscellany 2: intelligence, savannah, the Cambrian (General)

by dhw, Tuesday, March 25, 2025, 09:32 (10 days ago) @ David Turell

Intelligence

DAVID: we have a tendency to assume our ancestors were dumb. They may well have invented knapping stone tools after seeing examples in nature or directly invented the process. Now we have both proposals. Animal use of stone tools support the idea that naturaliths were the first step.

dhw: This is a comment which I wholeheartedly endorse. Many humans have a tendency to assume that not just our ancestors but also our fellow organisms are dumb. In the great battle for survival, even the smallest organism must have some sort of intelligence to recognize problems and dangers. Over the course of time, most have eventually become extinct, because their intelligence is not equal to the task, but many have survived for hundreds of thousands of years before that happened. Bacteria have survived from the very beginning. Human scepticism has been beautifully summarized by James A. Shapiro as “large organisms chauvinism”. This article deals simply with sapiens chauvinism in relation to our ancestors.

DAVID: correct.

I’m delighted with yet another agreement, which should cover the entire range of life from bacteria through all species to ourselves.

The savannah theory

DAVID: The savannah theory is now unsupported by the new findings but still a logical theory.

dhw: It is “unsupported” by the new findings because the new findings have nothing to do with the question of sapiens’ origin! You have said yourself that no-one knows the origin, so all we can have is unsupported theories, including your own, which attributes the origin to your God performing operations on individual pelvises, legs and possibly brains, though your post above suggests he left brains to design their own evolution until he decided to pop in and do a sapiens special.

DAVID: Lucy became Erectus and Erectus became sapiens is all we know.

dhw: Even that is a bit controversial, but in the context of our discussion, thank you for now agreeing that none of the articles have in any way demonstrated the fading of the savannah theory.

DAVID: With the new findings the savannah theory has been diluted from primary importance.

How many more times? The new findings tell us nothing about where, when or why our ancestors first descended from the trees. Who decides what is of “primary” or “secondary” importance? Do you think the savannah theory is of secondary importance compared to your belief that one fine day your God popped in to operate on the legs and pelvises of a group or groups of tree-dwellers?

Human origin from different groups

QUOTE: Fossil evidence suggests that species such as Homo erectus and Homo heidelbergensis lived both in Africa and other regions during this period, making them potential candidates for these ancestral populations

DAVID: this extensive study tells us how various hominins may have mixed to make us as the sole surviving form. It does not satisfy dhw's quest for a full theory as to the development of bipedalism.”

We covered this theory last Thursday and Friday. You have stated categorically that we are descended from Erectus, so I’m really not sure where this theory leads us. It certainly doesn’t lead to the start of the process, and our discussion began with your belief that the savannah theory was fading, though you now acknowledge that it is a logical explanation.

Theoretical origin of life: diurnal stress

Oxygen levels rising and plunging:

https://www.sciencealert.com/extreme-feast-and-famine-cycle-sparked-explosion-of-life-o...
QUOTES: "Imagine a world where the oxygen you need changes dramatically between day and night.

"Now, picture early animals trying to survive in such an extreme environment. This was the reality for early animal life in oceans and seas about half a billion years ago. This was also the time when animal diversity boomed, in what is known as the "Cambrian explosion".

"Daily swings in oxygen levels on the shallow seafloor may have stressed early animals (the ancestors of all animal life today), pus hing them to adapt in ways that fuelled diversification."

DAVID: for once, a logical set of reasons for developing early life forms. Today's extremophiles show how they modify to handle stressful environments.

Your headline is way off track. This is an explanation of the Cambrian Explosion! And it’s good to see that you accept not only the ability of extremophiles to modify themselves, but also that of the ancestors of all animal life today, which would include ourselves. The changes enabling these life forms to survive would have had to be very rapid, or they could not have survived. So for once you now you have “a logical set of reasons” for the Cambrian Explosion.