H. sapiens: The Last 12,000 Years

By Fil Munas

A COSMIC CONUNDRUM—This astonishing book follows our ascendancy from just another hominin on the open African savannah to the alpha hegemon on Earth today endangering its entire future. Along the way, humans methodically outwitted their competition with phenomenal efficiency and indifference, to emerge in the modern 21st century as the linchpin of a major mass extinction of countless other lifeforms cohabiting their planet with them. The shredding of our fragile ecosphere by massive proliferation and monopolistic overconsumption of Earth's precious resources by this single invasive species, along with the inexorable combustion of deadly fossil fuels to acquire the energy needed to sustain their profligate and lavish lifestyle, is threatening to drive H. sapiens itself into extinction within the next 300 years. This is the true story of that improbable adventure!

• Language: English
• Publisher: ANAP Publishers
• Release date: Dec 26, 2022
• ISBN: 9798986028705

Book preview

PREFACE

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This authentic tale recounts the grand adventures of the mammalian species Homo sapiens (H. sapiens) on a small rocky planet of a solitary star system in our galaxy. It traces our journey from speciation 300,000 years ago on Earth, to this critical impasse in the 21st century where we find ourselves plumb in the middle of a massive anthropogenic extinction of lifeforms on this only planet we can call home. How did we get here?

History should be experienced as it would appear to someone living at the time it actually happened, not by a different civilization’s codes and customs. So without judging our past, we will try to evaluate its impact upon our future.

Throughout these pages, this narrative explicitly acknowledges the modern empirical premise that our cosmos and all its constituent parts, including humans, evolved from preexisting archetypes and did not suddenly and inexplicably appear from nothing and out of nowhere.

At this point in our planetary history there still remain many important issues clouded in obscurity, but many others have been well explicated with logic and reason by our ancestors, just as we continue to do that same service for our descendants. We are looking for objective answers in the natural world. Faith does not contribute to this discussion.

Fil Munas

February 14, 2022

Chapter One

IN THE BEGINNING

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HOMO SAPIENS

(Taxonomy)

Domain: Eukarya

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Subfamily: Homininae

Tribe: Hominini

Subtribe: Hominina

Genus: Homo

Species: Sapiens

Planet Earth is about 4.5 billion years old1 and orbits a solitary star inside that star’s habitable zone. Biological life—the property of matter to spontaneously feed and reproduce itself—began on Earth at least 3.7 billion years ago2 because that is the age of some of the oldest rocks which carry fossil evidence for life on Earth.

Our Earth is one of many millions of differently-sized objects ranging from pebbles to planets that orbit a star called the Sun, which orbits a galaxy known as the Milky Way containing many billions of such stars; the Milky Way inhabits a Universe that is perhaps home to many trillions of such galaxies. That is the manifest landscape on which we live our lives and die.

An animal called Homo sapiens [H. sapiens, Latin for Wise Human] evolved as a distinct mammalian species on Earth about 300,000 years ago. The oldest known fossils of anatomically modern H. sapiens found in our world so far3 belong to a pan-African species of bipedal apes. Those fossils were discovered in 2017 at Jebel Irhoud in Morocco and were reliably dated to 315,000 ± 34,000 years in the past.

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Primatologists may employ the descriptor human to any of the many species in the genus Homo that once dwelled on our home planet during the Pleistocene Epoch. Here, for the sake of clarity, we will restrict that term just to Anatomically Modern Humans or AMH, i.e. only to H. sapiens and its descendants, not to other Homo or hominin species that also existed on Earth in the past.

The term "hominin" refers to any member of the hominini tribe of great apes of which there are currently three living species belonging to two separate genera, Homo and Pan. They are namely Homo sapiens (humans) and two other species, Pan troglodytes (chimpanzees) and Pan paniscus (bonobos or pygmy chimpanzees). The term hominin is also adopted by paleontologists to refer to all the now extinct members of the genus Homo and its predecessor genus Australopithecus.

The term "hominid" which we also use is broader and includes all four living great apes (orangutan, gorilla, chimpanzee, and human) as well as their extinct ancestors. The first three hominids listed here have more than one species recognized within their separate genera. Humans, by wide consensus, are all taxonomically a single species in their own distinct genus, Homo. Among the four living hominids only one, the orangutan, lives outside Africa in southeast Asia; the other three all live in Africa—and of those, H. sapiens is also found everywhere else on our planet.

Eyeballing human history from our first appearance in Africa roughly 300,000 years ago until the beginning of the Holocene Epoch 12,000 years back, we notice certain behaviors that could acquaint us to this very unusual great ape that habitually walked on two feet, and segue our way to the incredible last 12,000 years of its history.

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We traditionally separate our planet’s 4.5 billion years of chronological history into four principal divisions called Eons. This separation is done on the basis of major geologic and biologic transitions that characterize each individual eon. These four eons are sequentially named Hadean (hellish), Archean (origins), Proterozoic (earlier life), and Phanerozoic (visible life) Eons respectively.

The first three eons together make up a super-eon called the Precambrian, a lengthy period of almost 4 billion years after the planet formed. Microscopic unicellular life called prokaryotes (Greek for before nucleus) appeared early in the Precambrian, within about a billion years of Earth’s formation, and proceeded to proliferate and colonize the new planet. Prokaryotes were simple free-living cells lacking a discrete nucleus or other intracellular structures—just like modern bacteria are today. Life remained unicellular throughout the long Precambrian, except that these prokaryotes evolved into much larger, more complex, and now fully nucleated single cells called eukaryotes (Greek for good nucleus) about 2.7 billion years ago, perhaps after a billion years of prokaryotic evolution.

The fourth eon, the Phanerozoic, still in place today, began abruptly with the so-called Cambrian Explosion 541 million years ago producing diverse lifeforms. Within a short span of geologic time—less than 25 million years if you are counting—multicellular organisms or metazoans rapidly evolved from the unicellular eukaryotes existing until then, and during this interval virtually all the major phyla found today began appearing in the fossil record of that period. Those organisms representing these phyla, of course, were very tiny at that time, but they clearly incorporated the structural blueprints for all the different creatures that would evolve on this planet in the future.

Eons are divided into Eras, Eras into Periods, Periods into Epochs, and Epochs into Ages. The last four epochs of Earth’s history ending in the present one by ascending order are the Miocene, Pliocene, Pleistocene, and Holocene Epochs. The former two epochs belong to the Neogene Period, and the latter two to the Quaternary Period. These two periods of geologic time make up the Cenozoic Era of the Phanerozoic Eon. The four epochs mentioned here are particularly relevant to H. sapiens because the gathering of evolutionary forces that propelled the appearance of our own species all came together during that fabulous time horizon.

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The Miocene Epoch dawned on Earth 23.0 million years ago and lasted until 5.3 million years back, extending 17.7 million years in all. Early in that epoch, tailless apes first evolved from tailed monkeys in Africa and blazed the path that eventually led to us. The Pliocene Epoch followed the Miocene, from 5.3 million to 2.6 million years ago. During the 2.7 million years of the Pliocene, Earth’s climate became cooler, drier, and more seasonal, reminiscent of climatic conditions we find today.

The first hominins, australopithecines, emerged from ancestral apes in Africa and thrived in the Pliocene. These remarkable creatures were walking upright and using stone tools by the end of that epoch. The Pliocene was followed by the Pleistocene Epoch which lasted another 2.588 million years. The Pleistocene saw the emergence of the genus Homo and was eyewitness to the deadly evolutionary struggle within that genus and the eventual emergence of just one victorious species, H. sapiens, as that epoch ended.

Which brings us to the Holocene Epoch beginning 12,000 years ago and continuing into the present. The Holocene ushered in the overarching technological dominance of H. sapiens on Earth along with the wholesale major mass extinction of other lifeforms across our planet.

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Apes evolved in Africa about 24 million years ago when that continent was an island separated by water from other land-masses on Earth. The best known of these early African apes was Proconsul that lived in East Africa about 23 million years ago at the start of the Miocene. Proconsul was evidently an ape but seems to have retained many monkey-like traits in its spine, pelvis, and forelimbs. That animal was a quadrupedal branch walker moving on top of tree limbs, rather than a brachiator swinging from branch to branch like the fictional Tarzan. The primary feature linking Proconsul to apes is its lack of a tail. This animal, possessing a suite of Old World monkey and ape characteristics, is tentatively placed in the ape superfamily.

Around 17 million years ago, lowered sea-levels because of mounting glaciation provided a suitable land-bridge for these early Miocene apes to leave Africa and enter Eurasia, along with elephants, pigs, and rodents. These apes had by then developed a thick coating of enamel on their teeth, enabling them to masticate harder foods such as nuts and seeds, an option not available to their Proconsul ancestor. This evolutionary adaptation allowed these Eurasian apes to diversify into at least eight different varieties within 1.5 million years of emigration out of Africa to Europe and Asia.

By 13 million years ago apes had spread throughout Eurasia. Among these were Sivapithecus in Asia and Dryopithecus in Europe4. They both possessed a remarkably similar anatomy to modern great apes. These two lineages survived the major climate changes that marked the end of the Miocene.

The rise of the great Himalayas, a huge mountain range along the northern edge of the Indian subcontinent, made Europe much cooler and dryer. Starting around 10 million years ago, deciduous woodlands replaced subtropical forests in Europe and many tropically acclimated animals perished on that continent as a result of this change.

While other Eurasian apes became extinct around this time, the two Miocene apes mentioned here remained alive by moving into southeast Asia (Sivapithecus) and back into Africa (Dryopithecus). All existing great apes seem to have descended from them.

Phyletic analysis of their facial sinuses may suggest that Sivapithecus could be ancestral to orangutans while Dryopithecus to the African great apes, including H. sapiens5. Dryopithecus had prominent frontal sinuses which are bilateral cavities in the forehead or frontal bone. That evolutionary feature links this animal to the African great apes and to humans who all possess frontal sinuses. Sivapithecus on the other hand lacked this frontal sinus like contemporary orangutans do, thus establishing a different evolutionary lineage for that southeast Asian great ape.

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Humankind’s ancestral genus, Australopithecus, became extinct during the early Pleistocene after speciating that amazingly innovative successor genus, Homo6. This particular genus of apes—Homo—is characterized by a relatively large brain, limb structure adapted to a habitually erect posture with bipedal gait, well developed and fully opposable thumbs, hands capable of powerful yet precision grips, and the ability to make and use standardized tools employing one tool to make another.

Many species in the genus Homo emerged during the Pleistocene, some of them living cheek-by-jowl with H. sapiens during this very eventful period of our evolutionary history. Among the many hominins that lived in the Pleistocene and listed here perhaps in order of their appearance are H. habilis, H. floresiensis, H. rudolfensis, H. erectus, H. antecessor, H. heidelbergensis, H. neanderthalensis, H. naledi, and H. sapiens; no species designation has yet been assigned to the Denisovan Homo and perhaps other hominins still to be identified from the fossil record. In the very intense and deadly evolutionary struggle that ensued among these hominins, every one of them became extinct except for us, H. sapiens.

The Pleistocene may quite literally be called The Great Hominin Age. It was during that epoch when some of these extraordinary creatures living in Africa established their masthead on that continent and then proceeded to emigrate to territory outside their continental preserve.

It was a time of unprecedented challenge for these conspicuously competitive and intelligent creatures. The Pleistocene landscape in Africa was rapidly transforming due to the ongoing climate change and climate instability at that time; the savage battle for territory and resources became intense and deadly among these hominins, with no prisoners taken.

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Early human culture as people now living would recognize it arose in H. sapiens late in the Pleistocene7. Art and music entered the human imagination, along with singing, dancing, cave-painting, engraving, etching, and stone carving being among their earliest cultural activities. Highly motivated individuals along with kith and kin emigrated from their point of origin in Africa and eventually trekked to every corner of the world looking for food, adventure, and mating opportunities. They sought a better future for themselves and their precious children, hopefully provisioned with plentiful resources and greater possibilities.

Humans continue emigrating across the world to this very day in ever increasing numbers over time, as they encounter even more peril and privation in their native lands and discover more direct and effective ways of traveling out of them. Compulsive emigration to new locations is a characteristic and perhaps genetically driven behavioral feature of this cosmopolitan mammal, acquired along an evolutionary path from their stay-at-home ancestors. This deeply rooted migratory impulse keeps all humans bonded together as one territorially connected global species and is the major factor for our current planetary dominance.

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Every living human on Earth belongs to a single distinct species known as H. sapiens8.

A biological species is traditionally defined as a population of organisms that can freely reproduce among themselves in nature and create fertile offspring. They are distinguished by reproductive sequestration from other populations, meaning that organisms from one species are usually incapable of reproducing with organisms from another species.

This rule may sometimes be ambiguous. Rarely, among certain very closely allied species, an individual may succeed in fertilizing another individual across an existing species boundary, producing live offspring. These inter-species offspring are called hybrids9, such as crossing a horse with an ass to make a mule, or mating a lion and a tiger to produce a liger. These hybrids are usually sterile and cannot conceive offspring by mating with other hybrids like themselves or one of the parent species; their genetic line ends with the hybridized individual and no new species is created. But in certain special situations, where the genetic congruence between two hybridizing species is extremely close, their offspring may show some degree of fertility though much reduced in these cases.

We had noted among the four extant hominids—orangutans, gorillas, chimpanzees, and humans—that the former three display more than one recognized species within their respective genera, while humans have only a single species in their own designated genus. So why did humans not speciate like those other hominids did?

The answer is pretty evident from biology.

To speciate, a subpopulation of a species requires a prolonged period of genetic isolation or physical quarantine, which is impossible to enforce in the case of H. sapiens because of our compulsive emigratory and sexual nature; merely a couple of individuals from outside the clade can genetically contaminate the entire speciating group and quickly cause reversal to the wildtype or common form. This trickling transfer of genes across our entire global population allows humans to remain integrated as a single interbreeding worldwide species. There is no need for a nonstop torrent of geneflow here; just a drop now and then is enough to keep everyone on the same page. Our compulsive emigration and vigorous sexuality took care of that.

In contrast, take gorillas for example. In their genus Gorilla they have two distinct species, Gorilla gorilla (Western gorilla) and Gorilla beringei (Eastern gorilla). These two gorilla species are separated by more than 1,000 miles of the Congo River basin sprawled across the heart of Africa. It is hard to imagine the Western gorilla sending emissaries across the Congo to the Eastern cohort a thousand miles away to maintain geneflow and avoid speciation. That evidently never happened because there are now two species of gorilla. Likely for similar reasons, there are two species of chimpanzees and three of orangutans. But only one of humans.

During a period of dramatic climate change about 300,000 years ago, humans evolved as a separate species on the African continent. Like other hominins living at that time they gathered produce and hunted animals, competed for territory and mates, and evolved behaviors that helped them respond appropriately to the many challenges and threats they encountered both as individuals and as cooperative groups living in unstable and hostile environments.

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Modern chimpanzees and bonobos are close kin to humans10. Starting out, they are both hominins. More than 96% of their genetic material is the same as we have; in fact, the typical human protein coded by our DNA has accumulated just one unique amino acid change since humans and chimpanzees split from a common simian ancestor around 6 million years ago during the African Miocene. To put this into perspective, the number of genetic differences between a human and a chimpanzee is just 10 times more than between any two humans. Darn, I’ll be a monkey’s uncle!

Following this bifurcation, those animals fated to be ancestors of H. sapiens entered the Pliocene as bipedal (upright, two-footed), sexually dimorphic (males bigger than females), relatively large-brained (at least one-third the size of a modern human brain), and tribally cooperative apes called australopithecines.

This name is derived from the Latin australis for southern and the Greek pithekos for ape, thus Southern Ape. They were so named because their fossils were first discovered in southern Africa. These australopithecines branched into two genera, Australopithecus and Paranthropus. The ancestral Australopithecus which led to the genus Homo was sleeker or more gracile than its cousin, the bulkier Paranthropus, that separated from Australopithecus before the Pleistocene began and was extinct before that epoch ended.

Around the same time that these australopithecines were actively evolving in Africa, their habitat was undergoing rapid transformation. The lush tropical forests that once thrived extensively in their territory began receding rapidly as the climate changed and became drier. Such accelerated climate changes occur from time to time in Earth’s history and often result in major habitat modification for existing lifeforms, or their extinction if they are unable to adapt. The forests were replaced by grasslands and savannah, prompting herbivores to proliferate. These herbivores in turn provided meat for the large carnivores that preyed on them.

The australopithecines or australopiths11 then living in the forest, feeding primarily on fruit, buds, and leaves, were increasingly cramped for living space as their forests shrank and receded due to major climate change. One branch of these australopithecines, represented by Paranthropus, followed an evolutionary path that adapted them to eating more variegated vegetable material such as the grasses and shrubs now replacing their beloved forests.

To chew this new diet they developed huge and broad cheek-teeth coated with thick enamel, powered by large chewing muscles attached to their jaws, endowing them with wide faces. These adaptations gave the robust Paranthropus the ability to grind down tough fibrous foods, the robust here referring to tooth and face size rather than to body size. These robust australopiths became extinct during the Pleistocene, many of them prey to the large carnivores who hunted them down as they were snacking on grasses and eating shrubs.

The second branch of australopithecines, the gracile Australopithecus, became hunters themselves and started adding meat to their diet. That was when these ancestors of humans switched from being primarily vegetarian to eating meat. These meat-eating hominins survived the climate crunch while their robust vegetarian cousins perished. For the gracile Australopithecus, the abundant energy provided by this new protein and lipid rich diet fueled the rapid enlargement and complex development of their brains. Incredibly, in modern H. sapiens, the brain though weighing just about 3 pounds or hardly 2% of total body weight, astonishingly consumes 20% of all the energy a person uses. That is 10 times the rate of energy consumption per gram of tissue that the rest of the body!

The particular species of gracile Australopithecus that would eventually lead to humans was a gregarious, taupe-colored animal with a bluish sheen, still sporting obvious fur on its sleek body. Males were a little under five feet tall and weighed about a hundred pounds. Females stood a foot shorter and tipped the scales at less than seventy pounds.

Being bipedal allowed these creatures to free their hands so they could grasp objects securely and carry food and babies around with them. By standing erect on two feet they could strategically peek over tall grasses to scan for refreshments or scrutinize their surroundings for lurking predators. They hunted only small animals at first—hares, porcupines, turtles—and scavenged for meat from leftover kills of the large carnivores; they loved eggs they poached from birds’ nests. At first they subsisted mostly on fruit, tubers, insects, eggs and such, but began adding flesh to their diet and became avid meat-eaters in time.

This remarkable creature possessed both ape and human characteristics. They had small canine teeth like we do and stood on two legs and regularly walked upright. But they had apelike faces and crania, and long arms with curved fingers adapted to climbing trees. It should be no surprise to us then that the natural aptitude and delight shown by our children to enthusiastically climb trees is reflective of this ancestral heritage.

Australopiths lived in Africa where they originated and seem not to have ventured beyond that continent. These creatures are now extinct. During their heyday in the Pliocene the genus included several related species that ranged over parts of their African homeland. For their time and space they were brilliant animals endowed with great curiosity and an inherently cooperative ethos.

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Australopithecus was the proximate ancestor of Homo habilis12 the first known member of our own genus, Homo. This species lived for about a million years in eastern and southern Africa, perhaps from 2.4 million to 1.4 million years ago.

H. habilis had a slightly larger braincase and smaller face and teeth than Australopithecus but still retained many ape-like features, including long arms and a moderately protruding or prognathic face. Its name which meant Handy Man was given to it in 1964 because this species was thought to represent the first maker of stone tools. Currently though, the oldest stone tools are dated older than the oldest evidence for the genus Homo, indicating they were first employed by our ancestral genus, Australopithecus.

The next notable hominin to follow H. habilis and probably its direct descendant was the world famous H. erectus, often called H. ergaster within Africa. This fabulous creature first appeared on that continent about 1.88 million years ago and perhaps inhabited our planet until as recently as 110,000 years back, when they made their last heroic stand on the island of Java in Indonesia. They had been our contemporaries for more than half of human history.

H. erectus was an intrepid globe-trotter, eventually dispersing its kind throughout the Old World.

After first spreading locally within Africa itself and populating that continent from their likely origin in the East African Rift Valley, this audacious hominin emigrated out of Africa in the Early Pleistocene to as far away as Georgia in the Caucasus (Dmanisi Man), India in south Asia (Narmada Man), China in northeast Asia (Peking Man), and Indonesia in the Far East (Java Man). Some have suggested that these exceptional animals built rafts to cross large bodies of water, though there is no hard evidence to support that view.

Just a million years ago these stalwarts of our genus Homo were an immensely successful species on their home planet, the dominant one around, the Big Kahuna. Unhappily for them, their dominance and expansion did not last forever. Unfavorable climate change and battles with those other vicious hominins crowding their space ensured their eventual downfall and extinction. H. erectus went on to decline after peaking globally about a million years ago. The bulk of them were gone by 143,000 years back. A few hid out on the island of Java in Indonesia until they too died out about 110,000 years ago.

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With the sole exception of H. sapiens, the extinction of all known Homo species that ever inhabited Earth, including at least eight identified ones, is indeed a striking historical anomaly. As we noted earlier in this narrative, many individual species of Homo once walked on

Reviews for H. sapiens

[American Muse · Rating: 5 out of 5 stars]

AN EXTRAORDINARY TALE!
A gripping and richly documented narrative of our human story spanning all the way from speciation in Africa to the present moment in the 21st century. This book faithfully follows the apocalyptic trajectory of our species H. sapiens, leading to insatiable fossil fuel combustion, environmental toxification, catastrophic climate change, and the current anthropogenic mass extinction of lifeforms on our planet. A compelling and challenging read!