0080 Between 1.5Myr and 200kyr (thousands of years ago), the Homo genus adapts to more and more proximate niches.  Imagine the signs offered by both nature and an increasingly wide repertoire of team activities.  Each constellation of signs pulls hominins towards adaptations involving both body and mind.  The body responds to signals.  The mind responds to signs.

Newson and Richerson discuss the Turkana boy, who undoubtedly displays promise before he gets trapped in circumstances that, over the following millennia, would allow his body to decay undisturbed and his bones to turn into stone.  Then, there is the fossilized skull of a male who had lost his teeth, found in the Caucasian Mountains and dating to 1.8Myr.

0081 What do these fossilized bones tell archaeologists?

Hominins are developing larger brains.

The Homo genus has a diet that is not the same as the australopithecines.  Perhaps, the new diet involves novel methods of food preparation, long before the domestication of fire.

Hominins domesticate fire long before the oldest hearths yet found, dating between 400 and 300kyr.  This period corresponds to around the time when the Neanderthal and the Denisovan lineages separates from (what is to become) the Sapiens.

0082 The domestication of fire, what an achievement.

The same style of Acheulean stone tool lasts for over a million years, then starts to change around the time when fire is domesticated.

0083 For thousands of years, fire has been considered elemental.

Mythologically, I could say that the Acheulean stone tools show that the hominins had tamed the element of earth.  The use of gourds to carry water tamed that element.  The use of manual-brachial gesture in hand talk domesticated the air. So, fire is the last element to be domesticated.

Oh! The Chinese civilization has one more element.  Metal!  That element belongs to our current Lebenswelt.   Earth, water, air and fire belong to the Lebenswelt that we evolved in.  Yet, our hand-talking ancestors could not label these elements as explicit abstractions, distinct from one another.  What is there to picture or point to?  Instead, these elements enter into implicit abstractions, as sign-vehicles that come into relation with sign-objects according to sign-interpretants held in body and in mind.

0084 After the domestication of fire, the pace of hominin innovation slowly increases.  The authors do not envision the possibility that the domestication of fire not only allows cooking (which increases the calories available from wild food), but permits talk to become… how to say it?.. a team activity, of sorts.  Yes, our ancestors shoot the breeze with hand talk around the fire after a meal.

Hand talk is no longer confined to task-oriented team activities.  A general vocabulary and grammar starts to evolve.

Our lineage loves to talk.  It is a wonderful as picking bugs off of one another.

0085 Before the first members of Homo sapiens appear, maybe around 200kyr, hominins talk with their hands.  The Neaderthals and the Denisovans probably practice fully linguistic hand talk.

Yes, before the appearance of humans, all hominins talk with their hands.  So, most stories are vaudevillian.  Hominins learn to laugh like never before.  Also, our ancestors begin to use their vocal tracts in precise ways, like a musical accompaniment to linguistic hand talk.  We learn to sing.  In community and mega-band and tribal gatherings, we synchronize ourselves through song.  In doing so, the vocal tract comes under voluntary neural control.  The larynx descends to accommodate a wider range of formant frequencies and then…

… with the evolution of Homo sapiens, speech is added to hand talk.

Hand-speech talks lasts for almost 200,000 years.