On Higher Ground and the Clines of Humankind

On Higher Ground and the Clines of Humankind

“Every man has forgotten who he is. One may understand the cosmos, but never the ego; the self is more distant than any star. Thou shalt love the Lord thy God; but thou shalt not know thyself. We are all under the same mental calamity; we have all forgotten our names. We have all forgotten what we really are. All that we call common sense and rationality and practicality and positivism only means that, for certain dead levels of our life, we forget that we have forgotten. All that we call spirit and art and ecstasy only means that for one awful moment we remember that we forget.”
 _G.K. Chesterton

cla·dis·tics

kləˈdistiks/

noun

BIOLOGY

1. a method of classification of animals and plants according to the proportion of measurable characteristics that they have in common. It is assumed that the higher the proportion of characteristics that two organisms share, the more recently they diverged from a common ancestor.

re·fu·gi·um

riˈfyo͞ojēəm/

noun

BIOLOGY

plural noun: refugia

1. an area in which a population of organisms can survive through a period of unfavorable conditions, esp. glaciation.

Peering deeper into human evolution by pouring over scientific papers and publications of the most recent findings and interpretations - you'll find a lack of consensus, varying schools of thought, and flat out arguments on shared subjects. Each scientist has their background and, thus, bias. Still, each perspective is valuable to the whole, and just as light through a prism has its rainbow of constituents that together make light itself - so do these varying points of view make a unity of our past.

Attempting to pinpoint the first learned use of fire by our genus Homo gives us a wide range of dates from 200kya to 1.7mya. The most recent evidence presented by scientific papers trends toward pushing the dates of fire use back into the age of the Oldowan tool-making industry >1.6mya. The earliest sites indicating habitual fire use are Wonderwerk Cave in South Africa at 1.7mya, then Koobi Fora in Kenya at 1.5mya, and Chesowanja in Kenya at 1.4mya. We will continue to see, especially with the emergence of modern human behavior, how this corridor from South Africa to East Africa to the Levant and into Eurasia was a repeating conduit for the spread of behavioral and technological developments. 

Just as in politics and from any age, you have conservative and liberal viewpoints among scientists. And the middle ground or general consensus being that fire use became widespread somewhere between Neanderthals and Homo Sapiens, no greater than 400kya. Yet, here, let me differentiate for proper understanding on how technologies may live or die. Understand, genetic and behavioral changes within a small population may spread rapidly. It's simply a smaller gene pool and thus genetically vulnerable to disturbance. But technological dissemination must roll out on the back of varying populations, each susceptible and under the guise of heritable culture. So, now Science is beginning to distinguish: Early Fire - specific and isolated paleolithic sites, from Late Fire - wide ranged habitual use <400kya. This is not hard to understand as today some have access to the Internet and some do not. Or better yet, some have access to capital and can understand it's best application, and some lack both access and understanding. But all innately understand the transference of information, in terms of the internet; virtually all understand using some valued or shared belief in an object as money for a medium of exchange. But what is missing as a fundamental element of understanding within the consensus on the use of fire is how it is ever so natural to develop. 

I came across a study by Lillian M. Spencer from the University of Colorado, on the savanna adapted antelope living at the time when Homo erectus first evolved, and a species of antelope which it ate. Based on the soil samples at sites where these fossils were found, these antelope were adapted to grasslands called secondary grasslands. Secondary grasslands are naturally, and most importantly, humanly, maintained. Not just these antelope, but grazing species of large herbivores in general became adapted to secondary grasslands just as Homo erectus evolved from Homo habilis, 2 million years ago. Now, secondary grasslands are maintained by fire that is caused by the increasing aridity of the climate. And if a species is forced by climate to evolve from a scavenger into a hunter, as stated in a previous post, it's not a wide gap between conceptualizing how a scavenger would naturally turn into a hunter in hard times. A scavenger observes first; they have to for their own safety. That observation is knowledge of where and when prey animals move and the predators that track them. It must be repeated that this is knowledge. Nothing random about it.

Professor John Gowlett of the University of Liverpool, "Bush fires in Africa, and probably elsewhere, are used by intelligent predators as a means of trapping prey. Animals such as cheetahs will position themselves so as to pounce on animals fleeing from the flames, and hawks will do the same." It's not a stretch for Homo habilis, as a scavenger, to have watched the movements of cheetahs, or even to watch the sky for buzzards and recognizing and following raptors as possible. Birds are commonly observed flying over wildfires capturing escaping insects. This is a natural behavior among many predators.

If non-human animals are intelligent enough to use fire in this manner, it is more than likely our early ancestors did also. But, one of these intelligent ancestors got closer, and picked up a burning stick. Whether it was used in a dominance display over a food or status conflict, or to further prod a dangerous and dying animal escaping from the flames and soon to be its prey, is unclear and will never be known. But what is known is that someone was watching, and someone mimicked, and then someone else until this particular group became dominant and successful. And if they could preserve and maintain this fire (transferring it to camp sites and lighting different consumables for later use), then they could set one - not create fire itself (I believe that would come later), but control it when found and maintained for hunting and cooking purposes. This could be the original purpose of hearth-building. 

It is my conclusion that this development, along with climactic changes pushing the Sahara Pump, along with early proto-language, and along with changing gender dynamics, aided the spread of the genus Homo out of Africa. And knowing that phantom evidence of a camp fire almost 2 million years old is nearly impossible with rapid erosion of ashes and cooked remains outside of bones, the archaeological record would, at first, be scant. But we see this as changing with evolving soil sampling techniques. And yet, the morphological record backs up this theory, as the genus Homo became more gracile (thinner torsos, longer limbs), the dentition became less occlusive (less crowded, smaller canines), and as a result, the brain case was less constrained by robust jaw muscles required to chew tough uncooked food items.

And that fire would have altered gender dynamics. As hunting became more wide-spread, and fire use became the norm - there is a delayed gratification and accumulation associated with cooking. You don't eat on sight of the kill. You butcher, you haul, and you wait. And the gatherers would be expert in advising on delayed gratification. So, if fire use and cooking were becoming more prevalent, we would begin to see it in the dimorphism (the difference in size between genders) in between Homo habilis and Homo erectus. And that we do - we see not only a decreased dimorphism, but an increased socialization. "Language, similar to what Homo sapiens employ, has it origins somewhere between 1.8mya and Homo heidelbergensis (~900kya) - due to new paleoanthropological, archaeological, and genetic reassessment of older data in lieu of and availability of ancient DNA." (Frontier in Language, Science 2013). Males would have to be more resourceful, than dominant; further sparking human intelligence - due, again, to female selection. 

This would not be the case for an entire species until "Late Fire," just as we have virtual hunter-gatherer populations today, in the midst of wide-spread technological dissemination. And it would not be the case for other sister-species in the genus Homo, as some would dimorphically "revert" (Neanderthal, perhaps Denisovan), and some would "advance" (Heidelbergensis, Sapiens). 

So we should view behavioral and technological adoption across a spectrum of species, time and place, instead of grouping it with widespread, automatic selection.

Within Africa, high-quality raw materials were available that "allowed for the full expression of technological skills," according to Yonatan Sahle of University of Capetown and University of California at Berkeley. These material sites were not far from mega-lake sites that "supported a bigger population. These mega-lakes might have attracted stable occupation, further fueling technological advances." 

But this is a regional bias. Because within a million years of wide-spread stone tool industry - peoples, and their technology with them, had traversed the Old World. So, Africa is the beginning, and will also be the beginnings of Homo heidelbergensis, archaic and modern Homo sapiens. Yet, not so for Homo antecessor, Homo neanderthalensis, Homo denisovan, or Homo floresiensis. Within and within these distant populations - we would recognize race, ethnicity and culture as we see it today.

With that recognition comes the understanding of self-identification and in-group and out-group categorization. Just as chimpanzee troops fight and maintain their territories against the out-group, early humans, the world over did the same. Violently.

First, with Homo erectus, as populations spread across Eurasia, there would be founding populations in domains and other populations spreading out nomadically, continuing to follow migrating prey animals. In particular, elephants (a literally vital relationship). They were gradually becoming the apex predator in new territorial enclaves of what is today Great Britain, Germany, France, Georgia, the Balkans, Turkey, Greese, Israel, Siberia, China, India, from tropical to temperate zones, until they would reach Indonesia. But no more of a population size of 2 million erectus - globally. Within this population, we could consider it wide and dispersed, with little or no contact between territories. And these regional enclaves would be at the mercy of climactic events over geological time, refugia - over a million years. These climactic and ecological effects would have distinctively shaped these isolated populations, into races. "The tinyness of the number of our human ancestors allowed a rather rapid evolution away from other groups who were also evolving in other small groups," says Robert Wyman, Professor of Microbiology, at Yale University. We would see an Asian Homo erectus, a European one, an Australasian race, and the founders, with some still migrating Africans (dubbed Homo ergaster within Africa).

For us Homo sapiens, it would only take 40k-70k years for our races to develop into what we are today. And only ~10K years for skin color to be reflected genetically. Less than .002% of our DNA reflects these superficial changes, according to the Human Genome Project. But, as blood types, cultures and language groups ignore borders - we are all morphologically and genetically the same species. For Homo erectus, we're talking about a period of 700k years (1.9mya - 1.2mya) until these populations in refugia develop from races into morphologically different species of Homo. 

Homo erectus - Levantine

Homo erectus - Ergaster - Africa

Homo heidelbergensis - Founder of Homo sapiens, Neanderthal and Denisovans, Africa and Eurasia until 200kya

Homo floresiensis, "The Hobbit" - Indonesia until 18kya (dwarf erectus)

Without art, without tribal jewelry, without body paint, without ocher or symbolic representation of some sort - despite their intelligences, it would have been hard to identify a stranger as friend or foe. They may simply not have cared to, due to experience and memorable history. More than likely, as competing groups of hunters - indeed they were foes. And with nomadic, dark-

skinned Homo erectus continuing to spread out of Africa, the difference in skin tone of a lighter complexion Eurasian erectus stranger would complicate interpersonal communication (possibly no shared language) - thus feeding into the idea of identifying the out-group as a foe. Just as today, protection of resources against the unidentifiable intentions of a strange out-group is what informs racism. Though it is actually an extension of this in-group/out-group dynamic.

The question arises, with widely dispersed groups, how these populations maintained themselves genetically? As usually, in male-bonded and dominated groups - the females seek (at their peril) mating bonds with males of a neighboring out-group. It decreases the prospect of harmful in-breeding, weakening the integrity of the genome, much less, the immune systems of its phenotype. So, the impetus is not conscious, but still natural. And that natural impetus feeds into the socio-sexual dynamics of the group. Chimpanzees kills females with children from an out-group, and will likely welcome a young, fertile, childless one into their own. So, as more fossils become available within these regions, alluding to what social dynamics can be gleamed - this would be a necessary topic to explore. But in what bones we have, we have an indication of some proximity of communities and the social exchanges within these archaic hominids.

As a reference (though not as a solid indication), for pre-civilization humans (courtesy of Professor Robert Wyman, Yale University):

• 56% of infants (0-3) died violent deaths
• 74% of ages 4-14 from violent deaths
• 46% of adult age died from violent deaths

In each of these age ranges, violence is the dominant form of death. More individuals die in the first three years of infancy - 15% more likely. This is not including death from accidents on the hunt or attacks by animals. Nor does it include communicable disease.

Instead, like chimpanzees, this is evidence of guerrilla warfare. Primitive warfare is not large groups of warriors going head to head, but instead, hit and run, raids, ambushes. Even against children, as indicated above, and has been observed by modern tribal groups in New Guinea. There can be derived from the data a clear line indicating how these earlier groups of humans would have interacted from their fossils:

• 40% of Neanderthal skeletons have head injuries
• 40% of Homo sapiens burials had spear or arrow points embedded in them.
• 90%+ of known modern human societies have been in involved in war. Those that did not are often driven into isolated refuges by war
• 86% of Native American tribes went raiding or had to resist raids at least once a year.

According to Wyman, there's one set of morals for an in-group (rarely resulting in death - even in male/male dominance conflicts), but out-group conflict almost always results in death. Think, "Thou shalt not kill" vs. the subsequent conquering of Canaan by the Hebrews in biblical terms. 

Vestiges of behaviors developmentally associated with this period of violence is the need to establish higher ground - for the simple purpose of surveying the landscape to guard against raids. We can see how caves could develop for this purpose. If not living quarters, then certainly well-maintained multi-purpose camps.

What exacerbates this problem is, of course, climate change. With lesser food density, the population has to spread out. Thus, females would be less interested in males flat-out competing, but in the most resourceful. As a result, male/male competition was reduced. Females reduced and eventually ceased their display of estrus (heat). Estrus attracts the most dominant, but the lack of it attracts the most intelligent:

"If he knows when she is in estrus, he also knows when she is not in estrus - and when she's not in estrus, he may have no evolutionary push to stay there, but to go out and try to find some other female. The purpose of not showing your estrus may be to keep the male uncertain of when you are fertile, and therefore, he has to attend to the female all the time... She's no longer interested so much in male competition, but in whatever resources the male can bring to her by having a male around continually. ....an increase in the male contribution to child rearing is one of the major reasons for the increased fertility of humans"

_Robert Wyman, Yale

Human females can reproduce four-five times faster than chimpanzees. It would appear, this is a result of environmental pressure and threat of real extinction of our genus - a bottleneck. For, in these refugia, it's very easy for a small population to go extinct. Our genome, even stretching back to Homo heidelbergensis as we can detect, indicates repeated occurrences of bottlenecks. The most recent being experienced by Homo sapiens at 74kya, due to a volcanic eruption of Mt. Toba  in Sumatra, with global consequences. Through various Milankovitch cycles, extinction of our genus Homo was always a very real possibility. And juxtaposed to these events, within the human genome, is evidence of a rapid evolution - adapt or die - just as in Australopithecus garhi adapted into Homo habilis, and habilis evolved into Homo erectus due to climactic pressures. And evolving rapidly denotes a struggle with the environment. When the relationship with the environment is optimized, evolution slows down. So, "mutations that occur in population bottlenecks spread rapidly within the decreased population," says Wyman.

Thus, some regions or refugia would be ahead of others in the process of evolving into our species. The record of bones indicates East Africa and Southern Europe, certain apomorphies (traits which characterize and ancestral species and its descendants) began to make their appearance in the descendants of Homo erectus ~800kya. While, these same recognizable changes would not occur elsewhere in the world until around ~400kya. As these changes are taking place rapidly in some populations and gradually in others, between 1.2mya - 800kya it becomes difficult to classify different species of our genus. We find traces of erectus in what we would morphologically perceive to be Homo heidelbergensis. 

This map also indicates countries in some ways intolerant to archaeology. There's a wide gap spanning from W. Africa to the Far East. In modern times, these countries are either more conservative, in political strife, or religious states (India is the exception and Pakistan does contain significant sites not listed here). A wide chasm thus remains in the understanding of our species history as a result.

Then again, during and after a period of rapid and diverse morphological changes, some 400ky later, we find traces of heidelbergensis in the birth of Homo neanderthalensis - as evidenced in the fossils of Atapuerca, Spain, in a site named Sima de los Huesos, or "The Pit of Bones."

"The Pit of Bones," is the first known burial site for any of our hominid ancestors. This place was repeatedly occupied between ~850kya - 400kya. It is a cave shaft of 43 ft in depth, at the bottom of which lies the remains of 28 Heidelbergensis. The morphological remains span from skeletal types of Homo erectus morphing into Homo heidelbergensis in the more ancient specimens, and Heidelbergensis being shaped into Neanderthals in the more recent layers. It is also the first evidence of a "symbolic burial" - a decorative handaxe was found next to one of the remains. These people must have had some sense of deep care and memoriam of their loved ones, and perhaps even an afterlife. 

The "cladistic-refugium" effect can account for any speculation on the admixture of these remains. For comparison, the earliest fossil of Heidelbergensis is Mauer mandible (jaw bone) found in Germany in 1907. The majority of the community agree on classifying this ~600kya fossil as a distinct species. Most importantly, we can bridge toward understanding them as morphologically distinguished out of an erectus lineage, ~621kya - 500kya during a "prolonged warm and humid"(Chen and Yu, National Taiwan Ocean University) period of Middle Pleistocene interglacial. As a reference, we're living in a warm interglacial now. Collective data such as this, along with genetics suggest a bifurcation into Homo sapiens and Neanderthal >530kya. But examined separately ("The Status of Homo heidelbergensis," Chris Stringer, Professor at London's Natural History Museum):

• The draft of the neanderthal genomes puts divergence between 440kya - 270kya.
• Complete mtDNA (matrilineal genes) sequences suggest 538kya - 315kya.
• Morphologic (fossils) specimens range from  592kya - 182kya.

Include these data with the range of occupation at the Pit of Bones and we could at least detect a solid range of Homo heidelbergensis morphology. We can even logically consider that more than one species may have co-existed or overlapped in time. Chris Stringer reports that this range, "can be viewed as an early date for Neanderthal characteristics... instead coexistence on the basis of late Heidelbergensis age estimates. Sima de los Huesos displays a mosaic of heidelbergensis and neanderthal features." The mandibles (jaws) resemble Neanderthals, but the craniums don't match in morphology.

The beginning evolution into Heidelbergensis out of Erectus is placed near ~1.2mya. The global climate of this time was shocked by a rapid glacial onset. Onto 400ky later we see another warm interglacial - and the distinction into Heidelbergensis start to realize. If we include them within the periods between 1.2mya - 500kya, then we should logically view them within what is called Middle-Pleistocene Revolution (Head & Gibbard, University of Cambridge). At 940kya, a significant Ice Age, and within 90ky afterward we see the first Heidelbergensis site, or settlement as we currently know. "These climate

transformations, particularly the increasing severity and duration of cold stages, have had a profound effect on the biota and the physical landscape, especially in the northern hemisphere." (Head & Gibbard 2005) With interglacials on a virtual +/-100ky cycle,this is the span of time when these refugia would have progressively aided regional speciation in refugia. 

Around this time frame, we also find the emergence of the newly discovered Australasian Denisovans. Due to introgression, 17% of its genome is a product of inter-breeding with Neanderthal. We tend to associate this group with Neanderthals as their tool-making industries overlap in western asia. From W. Siberia, SE Asia, Melanesia, as far east as the Philippines, and as far south as Australia 4% of the human genome of today is Denisovan. This species, based on genomic research, was entirely distinct from any other form of human. We share 33% less genetic similarity with them than with Neanderthals; that it had more diversity in its time and more longevity within Eurasia than Neanderthals.

From fossils found, we can deduce that it shared no other morphological traits with coexisting or extant humans. 

What we do know is that we can't identify the genetic origin of ~2% our DNA, though we know it is an extinct member of the genus Homo. That it introgressed into our genome ~35kya, that also split from its ancestors around ~700kya (Hammer, et al. Institute of Human Genetics and the Univ, of Arizona 2011). 

So, the Pleistocene Epoch spans from 2.5mya, and the emergence of Homo habilis. Within the the first stage, named the Gelasian, marks another strong and severe ice age, followed by interglacials and an evolving species. Next, from 1.8mya sees the emergence of Erectus, and its global migration. Why I personally believe Homo erectus was so successful in its development is the time periods of these interglacials. Glaciation obviously forced a contraction. The contractions not only affected these humans, but all flora and fauna thus environed. The onset of the aforementioned Mid-Pleistocene Revolution (1.2mya -500kya) expanded these interglacials. Before 1.2mya interglacials had a cycle of 41kya, and since 1.2mya the cycle has been glaciation every 100kya. The climate became more chaotic and unstable hereafter. An example of our current interglacial:

Through sharp, abrupt and periodic ice ages, followed by long and unstable interglacials, then in 100ky cycles interrupted by even more severe ice ages, these humans were driven into refugia that could buffer them against climactic instability and did serve as evolutionary incubators in developing adaptive mechanisms. Brain size increased to, and in some cases overlapped, the volume of modern humans. Thus, these smaller populations would mutate faster. And during interglacials would, at least a measurable percentage of the time, interact and introgress with other hominid species - hybridization events:

"When a lineage adapts a new (or changes its) refugial area, and it survivs for a number of Milankovitch cycles, expanding from and contracting into the new refugium instead of its original one, it is destined to evolve into a distinct population. Given enough time in isolation, it will be come a new species....a new refugia is unlikely to have the same flora, fauna, or ecology compared to the lineages original refugium, which contributes selective pressure to adapt and diverge." _Steward and Stringer 2012

This explains the wide range of morphological characters and clades at shared and spanning regional sites.

Milankovitch - Glacial  - Speciation Dynamics (Quaternary Glacial, Wikipedia)

At 780ky is the abrupt shock into the Calabrian Stage of the Pleistocene.

Sometime around 781kya, the magnetic poles reversed and caused an ice age that introduced a cold and dry climate globally. Thereafter of 781kya - 126kya, we have the definitive emergence of Heidelbergensis, the progenitors of Denisovan, Neanderthal, and Homo Sapiens. 

Euro Heidelbergensis

Between 500kya and 300kya, Heidelbergensis experiences a period of gigantism. Some South African fossils are from individuals that were routinely over 7 ft. As did other secondary grassland-dependent animals grow in size.

The Elephant with Homo erectus is similar to that of cows for Americans. But, less of a dietary preference, and instead, a dietary dependence. At it's birth, there were 12 species of pachyderms roaming Africa and the Old World. Most of them were giants. Now, there are only two species - African and Asian - which remarkably migrated and diverged just at the time of the early migrations of Erectus. With this relationship we will begin to deconstruct the behavioral, subsistence, and environmental models associated with the rise, existence and disappearance of Heidelbergensis. 

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