Sorry for the delay this time, but I'll compensate with new insights into where we came from...
Not everyone agrees how to interpret the “Big Bang” of human culture that seems to have happened around 40,000 years ago (that I describe and discuss in Existence), a relatively rapid period when we got prolific cave art, ritual burials, sewn clothing and a vastly expanded tool kit… and lost our Neanderthal cousins for debatable reasons. Some call the appearance of a 'rapid shift' an artifact of sparse paleo sampling. V. S. Ramachandran agrees with me that some small inner (perhaps genetic) change had non-linear effects by allowing our ancestors to correlate and combine many things they were already doing separately, with brains that had enlarged to do all those separate things by brute force. Ramachandran suspects it involved “mirror neurons” that allow some primates to envision internally the actions of others.
My own variant is “reprogrammability…” a leap to a profoundly expanded facility to program our thought processes anew in software (culture) rather than firmware or even hardware. Supporting this notion is how rapidly there followed a series of later “bangs” that led to staged advances in agriculture (with the harsh pressures that came with the arrival of new diets, beer and kings)… then literacy, empires, and (shades of Julian Jaynes!) new kinds of conscious awareness… all the way up to the modern era’s harshly decisive conflict between enlightenment science and nostalgic romanticism.
I doubt it is as simple as "Mirror Neurons." But they might indeed have played a role. The original point that I offered, even back in the nineties, was that we appear to have developed a huge brain more than 200,000 years ago because only thus could we become sufficiently top-predator to barely survive. If we had had reprogrammability and resulting efficiencies earlier, ironically, we could have achieved that stopping place more easily, with a less costly brain... and thus halted the rapid advance.
There’s much ballyhoo that researchers found that just 1.5% to 7% of the human genome is unique to , free from signs of interbreeding or ancestral variants. Only when you stop and think about it, this is an immense yawn. So Neanderthals and Denisovans were close cousins. Fine. Actually, 1.5% to 7% is a lot! More than I expected, in fact.
Much is made of the human relationship with dogs… how that advantage may have helped relatively weak and gracile humans re-emerge from Africa 60,000 years ago or so… about 50,000 years after sturdy-strong Neanderthals kicked us out of Eurasia on our first attempt. But wolves might have already been ‘trained’ to cooperate with those outside their species and pack… and trained by… ravens! At minimum it’s verified the birds will cry and call a pack to a recent carcass so the ‘tooled’ wolves can open it for sharking. What is also suspected is that ravens will summon a pack to potential prey animals who are isolated or disabled, doing for the wolves what dogs later did for human hunting bands.
== Other biological news! ==
A new carnivorous plant - which traps insects using sticky hairs -has been recently identified in bogs of the U.S. Pacific Northwest.
Important news in computational biology. Deep learning systems can now solve the protein folding problem. "Proteins start out as a simple ribbon of amino acids, translated from DNA, and subsequently folded into intricate three-dimensional architectures. Many protein units then further assemble into massive, moving complexes that change their structure depending on their functional needs at a given time. And mis-folded proteins can be devastating—causing health problems from sickle cell anemia and cancer, to Alzheimer’s disease."
"Development of Covid-19 vaccines relied on scientists parsing multiple protein targets on the virus, including the spike proteins that vaccines target. Many proteins that lead to cancer have so far been out of the reach of drugs because their structure is hard to pin down."
The microbial diversity in the guts of today’s remaining hunter-gatherers far exceeds that of people in industrial societies, and researchers have linked low diversity to higher rates of “diseases of civilization,” including diabetes, obesity, and allergies. But it wasn't clear how much today's nonindustrial people have in common with ancient humans. Until bio archaeologists started mining 1000 year old poop - ancient coprolites preserved by dryness and stable temperatures in three rock shelters in Mexico and the southwestern United States.
“The coprolites yielded 181 genomes that were both ancient and likely came from a human gut. Many resembled those found in nonindustrial gut samples today, including species associated with high-fiber diets. Bits of food in the samples confirmed that the ancient people's diet included maize and beans, typical of early North American farmers. Samples from a site in Utah suggested a more eclectic, fiber-rich “famine diet” including prickly pear, ricegrass, and grasshoppers.” Notably lacking -- markers for antibiotic resistance. And they were notably more diverse, including dozens of unknown species. “In just these eight samples from a relatively confined geography and time period, we found 38% novel species.”