Last Ape Standing

Chip Walter, “Last Ape Standing: The Seven-million-year Story of How and Why We survived”, Walker & Co.,  (2013) 181 pgs. 

Now and then, I come across a book I judge as extremely important to my understanding of just who we are and how we got here—this is such a book.  Author Chip Walter explains why Homo sapiens survived in their seven-million-year journey while twenty-six other hominids did not, drawing on scientific discoveries as recent as weeks before publication.  He examines the survival value of such factors as premature births, long childhoods, and an extremely social nature of developing hominds all beginning with a modification in our big toe, from curled to straight, (which made upright walking easier, our straight big toe supports about 30% of our weight) and ended with self-awareness.

The arc of human evolution bears an uncanny resemblance to the children’s game Fortunately/Unfortunately. Fortunately, our ancestors evolved in the African rain forests. Unfortunately, the rain forests began to disappear. Fortunately, we could survive on the savanna. Unfortunately, the savanna had little food and many predators. Fortunately, at least 27 species of protohumans developed different traits to solve such problems. Unfortunately, only one protohuman survived. Fortunately, it was us.

My Notes:

Pg. xi:  Current scientific consensus agrees that twenty-seven separate human species have evolved on planet Earth, many of them lived side by side, some with us.  Twenty-six of them are no longer with us, done in by their environments, predators, disease, or the unfortunate shortcomings of their DNA.  We, the Homo sapiens, are the remaining survivor.  The story begins between four and seven million years ago when the first humans came into existence when fossil evidence points to a primate splitting from the last common ancestor humans shared with today’s chimpanzees. (Pg. 5).

Pg. 26:  Mostly we think of Darwin’s “descent by natural selection” as a chance transformation of newly arrived mutations—usually physical—into an asset rather than a liability, which is then passed along to the next generation.  So paws become fins in mammals that have taken to the sea.  The spindly arms of certain dinosaurs evolve into the wings of today’s birds.  The ballasting bladders of ancient fish become the predecessors of land animals’ lungs.  Evolution also can shift the times when genes are expressed and hormones flow, which not only alters looks but behavior.  Put another way, after birth, processes that were once prenatal in our ancestors become postnatal in us.  By being born “early,” our youth is amplified and elongated, and it continues to stretch out across our lives into the extended childhood that makes us so different from the other primates that preceded us. 

Pg. 75:  Between 160,000 and 200,000 years ago the first anatomically modern humans emerged, probably near Ethiopia.  Among them was a woman to whom every living human today is related, at least when looking at mitochondrial DNA as a marker.

Pg. 78:  About seventy thousand years ago a severe wintry climate set in.  This frigid swing began to systematically rub out life everywhere on the planet.  (We are living right now in what scientists call a slim “interglacial” period of this ice epoch.)  Only about ten thousand total adult homo-sapiens in a troop here or there, were scraping out a living before the glaciers receded. 

Pg. 80:  Seventy millennia in the past the most powerful volcanic explosion to rock the planet in a million years shattered the island of Sumatra, Indonesia and nearly wiped out Homo sapiens on Earth.  It was twice as powerful as the largest eruption in recorded human history, which took place in 1815 at Mount Tambora in Indonesia.  This 1815 eruption resulted in the year without a summer because the globe-circling debris from the eruption so severely cooled the planet.  So, the much earlier Toba explosion may have driven global temperatures down as much as 27 degrees F.  Studies show that an ash layer a half foot thick draped all of south Asia, and quickly blanketed the Indian Ocean and the Arabian and South China seas as well.  Neanderthals in Europe and west Asia were apparently spared the direct effects of the volcanic fallout.  Homo erectus living at the time in east Asia and Homo floresiensis, the “hobbits” who lived close by seemed to have escaped because they were upwind of the debris.  The humans, our ancestor Homo sapiens scattered throughout Africa, seem to have been hit the hardest and were nearly wiped out. 

Pg. 86:  Around seven hundred thousand years ago, an altogether new, and crucially important, creature called Homo heidelbergensis evolved (name derived from Heidelberg, Germany where the first specimen was found).  It is the species that both we and Neanderthals descended from.  (Neanderthals passed into extinction some twenty-five thousand years ago.)  Neanderthals had large brains—1100 to 1400cc, as large as ours. 

Pg. 89:  By the time we and Neanderthals had emerged, at least four (and probably more) intelligent, self-aware human species were still living on planet Earth.  (Evidence for this is very recent, it came out as the author was writing this book).

Pg. 104:  Insights into Neanderthals and their world have altered considerably within the past decade as new fossils have been discovered, and scientists have applied genetic technology in creative ways to plumb exactly who these people were.  It’s now clear that though they lived under brutal and stupefying circumstances during their nearly two hundred thousand years in Europe and Asia, they were themselves neither brutal nor stupid.  In fact, their brains were slightly larger than ours are today.  Although their worldwide population never reached into six figures, they still managed to range thousands of miles in all directions, as far west as the Iberian Peninsula and as far east as Siberia.  Their physical adaptation to the cold is among the reasons we think of them as brutish. 

Pg. 113:  For twenty-five thousand years, nearly three times longer than we have been recording our own history, Homo sapiens and Neanderthals shared the same parts of the world.  Over time, and as the Cro-Magnon people wandered deeper into Europe, the species must have met again and again.  We do not yet know if they cooperated or waged war.  In any event, Neanderthals became extinct some twenty-five thousand years ago after sharing the planet with us for twenty-five thousand years.

Pg. 114:  The Cro-Magnons were the earliest Homo sapiens to reach Western Europe, and the people who first encountered and then coexisted with Neanderthals in places we now know as France and Spain, beginning some forty thousand years ago.  Their genes are today evident in nearly all of us.  In 1940 their creative talents were discovered on the wall paintings in the Lascaux caves in France. 

Pg. 143:  Most paleoanthropologists agree, for the time being at least, that Homo sapiens emerged 195,000 years ago.  By this they mean creatures that were anatomically modern—they looked like us but evidence indicates that for a hundred thousand years they didn’t begin to think like us until forty thousand years ago.  And the evidence by this time is both stunning and global.  So, forty thousand years ago Homo sapiens had made their way out of Africa for good and were busily populating Europe, east and south Asia, and making their way through Indonesia clear to northern Australia. 

Pg. 147:  The importance of dance and music in the human psychic is probably best illustrated by a single startling fact.  We are the only primates that can tap our foot or move our body in time with a specific rhythm.  It’s wired into us, but not into our chimp or gorilla cousins, which tells us that it is a trait that like language, big toes, and tool making evolved sometime over the past seven million years.

Pg. 152:  It is clear that between seventy-five thousand and forty-five thousand hears ago, some cerebral critical mass was occurring in Homo sapiens.  Neoteny (the retention of juvenile characteristics in the adults of a species, as among certain amphibians) had created a nimble, pliant brain that remained flexible throughout life and generated both unique people and unique ideas.  We had evolved into born learners, genetically encouraged to seek out and, by some strange neuronal alchemy, devour surprise and transform it into knowledge.

Link to  book summary