Archive for the ‘anthropology’ Category

Homo sapiens is a Meat-Eater

December 9, 2018

An Hindu vegetarian didn’t like my blog post, “Native American Cannibalism and Dog-Eating,” (See: https://markgelbart.wordpress.com/2012/10/24/native-american-cannibalism-and-dog-eating/ ).  In the comments section he went on a long rant, explaining how humans are frugivores (fruit-eaters) and how humans aren’t anatomically built to eat meat.  He also has a pro-vegetarian website, promoting the same pseudo-science and misinterpretations of scientific facts that he wrote about in my comments section.  He claims meat-eating has been rare throughout human history, and our evolutionary ancestors ate a plant-based diet.  While it may be true that our very ancient ancestors lived on a diet of leaves and fruit with the occasional bird’s egg or insect, humans have evolved significant differences in dietary requirements and capabilities since then.  Meat is actually much easier for humans to digest than plant foods.  For example humans digest 97% of beef but just 89% of flour and 65% of most vegetables.

The ability of humans to digest large quantities of meat helped them survive the harsh climatic conditions of the Pleistocene when edible plant foods often became an unreliable or scarce resource.  If it wasn’t for man’s ability to eat meat, Homo sapiens would likely have become extinct. The added protein also contributed to brain development, making humans more intelligent.  The human brain is a large fatty organ that requires lots of protein.  The larger brain gave humans a crucial advantage over competing species.

The vegetarian’s response to my blog article made me curious about man’s diet during the Ice Age, so I searched for scientific studies of stable isotopic analysis of ancient human remains.  Scientists can determine the past diet of organisms by analyzing their bone chemistry.  I found 2 studies and was surprised to learn just how dependent upon meat at least some populations of humans were.

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Neanderthals relied heavily upon rhino and mammoth meat.

One study determined Neanderthals (H. neanderthalis) enjoyed a diet that was 80% animal and 20% plant.  The authors of this study looked at Neanderthal specimens from Troisiemo Cave in Belgium.  Apparently, Neanderthals relied heavily upon mammoth and rhino for their diet.  Other carnivores in the region fed more on horse, bison, and caribou.  Some scientists believed H. sapiens displaced Neanderthals because they had more flexibility in their diet.  But a 2nd study debunks this notion.  Scientists analyzed the bones of 3 anatomically modern human skeletons from Buran-Kay III, a rock shelter located in Crimea.  The specimens dated to between 37,000 years BP-33,000 years BP–shortly after the most recent date of Neanderthals.  They found these early humans also had a meat heavy diet, though they “possibly” ate more plant foods than Neanderthals.  This population of humans ate Saiga antelope, red deer, horse, and hare; but mammoth was their most important source of food. This study suggests H. sapiens competed with H. neanderthalis for the same food resources.

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The vegetarian claimed meat is not appetizing and kept comparing it to “roadkill.”  Meat looks appetizing to me.

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I’ll eat this roadkill every time.

Humans have continued to evolve since the Pleistocene.  The agricultural revolution has made plant foods more available, and the human body has evolved to eat more of them.  So, I don’t agree with the paleo-diet fad either.  I believe in eating a balanced diet that includes all 4 food groups.

References:

Drucker, D; et. al.

“Isotopic Analysis Suggests Mammoth and Plants in the Diet of the Oldest Anatomically Modern Humans from far Southeastern Europe”

Scientific Reports 2017

Wilburg, C.; et. al.

“Isotopic Evidence for Dietary Ecology of Late Neanderthals in Northwestern Europe”

Quaternary International 2015

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Terrifying Trench Warfare Caused the Flu Pandemic of 1918

October 29, 2018

Halloween scares are silly compared to the real world.  The universe is a really scary place, considering the potential for random disasters that could wipe out life on earth or at least a large segment of it.  Supernovas, asteroid impacts, tsunamis, and tornadoes are far scarier than a kid wearing a mask.  The other day I saw my cat terrorizing and killing a baby squirrel, and I thought to myself how harsh the universe can be for living organisms.   That particular animal never had a chance.  One would think humans would always be comforting and helpful to each other because the universe is so unforgiving.  History shows just the opposite is often true.  Humans kill other humans–a behavioral trait inherited from their evolutionary ancestors.  During the 20th century this frightening trait was illustrated in 2 world wars that left 67 million people dead.

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No man’s land on a battlefield in France during WWI.  Imagine being ordered to cross this into an hail of burning steel.

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Before the widespread strategic use of tanks trench warfare resulted in years of bloody stalemate on the Western front during WWI.

World War II caused more deaths than WWI, but battles in the earlier conflict were bloodier.  Men fought in static lines of trenches before the widespread use of tanks.  During WWII mobile tank warfare led to breakthroughs when many army divisions could be surrounded and thousands of troops would be forced to surrender.  Being in a prisoner of war camp sucked, but it was better than death.  But during WWI generals tried to break through enemy trench lines by bum-rushing opposing trenches with a mass of soldiers.  It was like forcing living human flesh through a meat grinder.  At the sound of a whistle 20 year old men were ordered to run across a devastated landscape known as “no man’s land.”  They ran into machine gun fire, artillery barrages, minefields, barbed wire, and poison gas.  Men were slaughtered and these attacks frequently failed.  Death notices were sent to thousands of families, following these futile offensives.  Just think how terrifying it was for these young men to know they were facing near certain death at the sound of a whistle.

The short lifespan of troops participating in trench warfare selected for an unusual strain of virus.  Most influenza viruses are not that deadly because if the host dies rapidly, fewer virus spores will survive to infect other hosts.  But hosts were dying rapidly in WWI trenches, and a virulent strain of virus, known as the Spanish flu, was just as likely to infect other hosts as the less virulent strains.  The virus began to spread in the spring of 1918.  Demobilization during the fall of 1918 when soldiers rejoined the civilian world caused a surge in the pandemic.  The Spanish flu continued to afflict the populations through the winter of 1919.  Scientists estimate this influenza virus killed 50-100 million people–probably more than both world wars combined.  It infected 25% of the world population and had a mortality rate of 5%-10% (most influenza viruses have a mortality rate of .1%).  Healthy people in their  20’s and 30’s suffered an higher mortality rate than the elderly who are usually more vulnerable to flu epidemics.  Scientists think this flu strain was different from the initial flu strain this generation first encountered during the 1890’s, and their imprinted immune systems were maladapted for it.

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Spanish flu virus.

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The Spanish flu virus may have killed up to 100 million people.

I’m not afraid of vampires, werewolves, and witches; but the possibility of global war and disease pandemics are much more frightening to contemplate.

Reference:

unnamed author

“A Deadly Touch of Flu”

The Economist September 29, 2018

Pleistocene Bread

August 9, 2018

It is the 20th anniversary of my sourdough starter.  With my sourdough culture I make great bread, pancakes, and dumplings; and it can also serve as an excellent coating for fried fish and shrimp.  Wild yeast living in the atmosphere of Augusta, Georgia helps my bread rise without the need for store-bought yeast during summer months.  (The wild yeast needs some help when the house is cold.)  The discovery of bread must have been an happy and tasty accident.  Hunter-gatherers collected the seeds of wheat and other grains, but to make them more palatable, they removed the chaff, pounded the grains with rocks, and cooked them in water.  Crushed grains left over night or for a few days fermented.  This gruel could be consumed as a primitive beer or baked into bread.  Archaeologists debate over whether beer was a byproduct of bread-making or vice-versa.  Most think the effort to gather individual grass seeds was so tedious when many other plant and animal foods were available that only the desire for alcohol would’ve inspired primitive people to labor so intensely.  It should be noted this primitive beer did not taste like modern beer.  It was sour.  Bitter hops weren’t added to beer until the year 736 AD in Germany.

I started my sour dough culture in 1998 by exposing flour and water to air.

My sourdough bread fresh from the oven.

Archaeologists believe humans didn’t deliberately plant wheat until 10,000 years ago.  Yet, burnt bread crumbs, resembling toaster detritus, were recently discovered at a site dated to 14,400 years ago in Jordan.  The Natufians, hunter-gatherers roaming through the Middle East then, lived in sunken houses with stone floors and fireplaces, and apparently, they made bread.  Today, this region is a desert, but during the late Pleistocene it was an open woodland with many species of edible grasses growing between widely spaced trees.  The people often feasted on gazelle, wild sheep, and hare; and they ate bread too.  The bread was made with a mixture of primitive wheat, rye, millet, barley, possibly oat, and papyrus root.  The latter ingredient likely added necessary sugar to help fuel the yeast.  Modern bakers always add a little sugar or honey to their bread dough.  Archaeologists sifting though the site found 65,000 plant specimens including 95 species, but papyrus was by far the most common making up 50,000 of the specimens.  They also found mustard seed, peas, and of course the wheat, barley, rye, millet, and oats.  Mustard greens are edible, and the seeds were probably used as a condiment.  So some people were already eating bread during the Pleistocene.

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Artist’s representation of Natufian houses in Jordan 14,000 years ago.  The foundations are still visible.  They made bread in these houses.  The landscape was not as barren then as depicted in the illustration.

Reference:

Otaegui, P.; et. al.

“Archaeobotanical Evidence Reveals the Origin of Bread 14,400 Years Ago in North-Eastern Jordan”

PNAS July 2018

See also: https://markgelbart.wordpress.com/2012/08/05/humans-cultivated-figs-during-the-pleistocene/

A Relic Population of Pleistocene Man (Homo sapiens) on North Sentinel Island

March 22, 2018

Homo sapiens first left Africa about 60,000 years ago.  Most of the original tribes that left Africa either perished in the harsh environments of Asia or were replaced by later arriving tribes that had developed superior technology or subsistence strategies.  The people who eventually conquered Asia look and behave quite differently from the initial African colonizers.  However, there is a relic population of early Homo sapiens on the Andaman Islands located in the Bay of Bengal near Malaysia.  Scientists believe a land bridge connected the Andaman Islands with Malaysia during Ice Ages and early Homo sapiens walked there.  Rising sea levels isolated the Andamanese and protected them from being killed or assimilated by groups that later conquered Asia.  Genetic evidence suggests the Andaman Islanders diverged from the rest of humanity 60,000 years ago.

Andaman Islands.PNG

Location of the Andaman Islands.  They were connected to Malaysia during Ice Ages due to lower sea levels.

The Andaman Islanders are related to African pygmies but are considered negrittos–people smaller than average in size but larger than pygmies.  This smaller stature probably helps them survive on islands where they have less food.  It’s an evolutionary advantage to have lower caloric intake needs on islands, and dwarfism is common among large species of mammals that became trapped on islands.  People on 1 particular Andaman Island known as North Sentinel have been isolated longer than any other Andaman Islanders.  Their language is far different from the 2 languages spoken on the other Andaman Islands, and they have incredibly primitive technology.  All attempts to communicate with them have failed because no one in the outside world understands their language. The North Sentinelese kill outsiders on sight, explaining why they have been isolated for so long.  They have no agriculture, and some believe they depend on lightning strikes for fire, though I doubt this.  I think our evolutionary ancestors (H. heidelbergensis and H. erectus) had fire, but who knows–maybe the North Sentinelese forgot fire-making knowledge.

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The unfriendly North Sentinelese attack outsiders on sight.  Here, they are about to shoot arrows at a passing helicopter. Note the red-ochre painted faces.

There are only 40-400 North Sentinelese living on the 24 square mile island.  The island vegetation prevents an aerial survey of the population.  They eat wild pigs, fish and shellfish, and wild plant foods.  The Indian government (owners of the Andaman Islands) abandoned attempts to contact the tribe and outlawed other outsiders from visiting the island.  It’s unsafe for outsiders because they will be attacked, and introduction of infectious diseases would probably wipe out North Sentinelese because their immune systems have been isolated from other humans for so long.  The North Sentinelese recently murdered 2 drunken fishermen who drifted too close to shore.  Also not long ago, a typhoon wrecked an oil tanker on a coral reef off the island, and the crew had to fight for their lives before being rescued.  The North Sentinelese stripped the ship bare.  They shoot arrows at all passing helicopters.

The North Sentinelese represent what Pleistocene man was like 60,000 years ago.  Pleistocene people were small of stature and dark-skinned.  Genetic evidence of a 10,000 year old skeleton in Britain suggests even some Europeans were dark-skinned during the Pleistocene.  They had primitive technology and were hostile to strangers.  The descendants of these small violent humans conquered the world.

Reference:

Endicott, P. et. al.

“The Genetic Origins of the Andaman Islanders”

American Journal of Human Genetics  72 (1) 2003

U.S. Government Will Allow Religious Nuts to Bury a 1 of a Kind Scientific Specimen

February 13, 2017

Democrats like to paint Republicans as being anti-science and of course this is true.  Republicans dispute scientific facts about everything from the harmful effects of pollution to the fundamental basis of biological science.  But when it is politically expedient, democrats can be just as anti-science.  On September 28, 2016 democrats caved-in to religious nuts who want to bury an extremely rare specimen where it will be lost forever to science.  The specimen is known as Kennewick man, first discovered 20 years ago.  It’s a nearly complete skeleton of a man who lived 9,000 years BP.  Skeletal remains of humans from this age in North America are so rare that only a few have ever been discovered.  The Army Corps of Engineers was going to let Native American tribes bury this precious specimen shortly after its discovery, but some scientists banded together and sued for the right to study it.  They won in court and luckily we now have increased our knowledge about the life of early archaic man in the Pacific northwest.  In 2015 a genetic study of this specimen determined Kennewick man shared a common ancestry with modern Native-Americans.  Unfortunately, this gave new legal momentum to the religious nuts who want to perform a ceremonial burial with the specimen, even though the study did not show any direct relationship with the tribes that inhabit the region today.  An amendment introduced by a democratic congresswoman was attached to a bill signed by then President Obama that will let these idiotic Indians throw away any more potential scientific knowledge we can learn about Kennewick man.  Future advancements in science could give us the opportunity to glean further knowledge from the specimen, but alas, unless there is another successful lawsuit, this rare specimen will be lost.  And it’s all because of the unnecessary deference given to stupid superstitions.

This clay facial reconstruction of Kennewick Man or "the Ancient One" was carefully sculpted around the morphological features of his skull, and lends a deeper understanding of what he may have looked like nearly 9,000 years ago. The remains will be repatriated to Columbia Basin tribes for traditional burial under legislation passed by Congress. Photo: Brittney Tatchell, Smithsonian Institution

The government is going to let ignorant Native-Americans bury this 9000 year old skull. A nearly 1 of a kind scientific specimen will be lost to science forever.

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I didn’t realize that Obama and the democrats were just as anti-science as the republicans.

In my opinion all religion is brainwashing for simple-minded people, and scientists know this, though they are often reluctant to say so.  If this dispute involved Christian fundamentalists, many scientists would be loudly protesting this amendment.  I’m sure they would call them “bible thumpers.”  But they seem unusually quiet about this because they are afraid of being called racist or politically incorrect for getting in a conflict with an indigenous belief system.  Well, I won’t be silenced.  I have no tolerance for ignorant beliefs no matter what group spouts them.  These Native-Americans are pushing their religion on us, and I think it is an outrage.  This specimen doesn’t belong to them.  They did not personally know Kennewick man.  None of their great-great-great-great-great grandparents knew Kennewick man.  In fact the ancestors of some of these tribes may have even fed upon Kennewick man’s kin.  (See: https://markgelbart.wordpress.com/2012/10/24/native-american-cannibalism-and-dog-eating/ ) Their claim on this specimen is based on phony political correctness. They can’t demonstrate to which tribe Kennewick man belonged, probably because none of the tribes existed yet when he lived.  So all the 5 tribes of the Pacific northwest (Umatilla, Nez Pierce, Colville, Yakama, and Wanapum) are going to share the burial ceremony, and the specimen is going to be buried in a secret location to prevent disinterment. How ridiculous.  What politically correct bullshit.  When Europeans discover thousand year old human specimens in Europe, no group ever comes forward to claim they have the right to the remains because they are relatives.  Human remains are not sacred…they are just bones.

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Native Americans on their way to bury scientific knowledge.

After I die I do not want to be cremated.  I want to be buried, so there is a chance my remains could be discovered by scientists 30,000 years in the future.  They can study or do whatever they want with my skeleton, and I’m pretty sure I won’t care.

Heinrich Events Caused Annual Mass Whale Strandings during the Pleistocene and early Holocene

October 10, 2016

Despite the universal chorus of politicized alarmists, earth is currently experiencing a period of relative climatic stability compared to the dramatic climatic fluctuations that occurred during the Pleistocene.  The presence of vast ice sheets in the northern hemisphere contributed to this ancient climatic instability.  Glaciers blocked rivers, creating huge glacial lakes.  Warm spikes in average annual temperatures weakened the ice dams and caused breaches.  Massive outflows of frigid fresh water and icebergs periodically flooded into the North Atlantic, shutting down thermohaline circulation.  The gulf stream normally carries tropically heated water into the North Atlantic, and this keeps overall climate temperate, but after torrents of cold fresh water stopped this process, average annual temperatures dropped as much as 15 degrees F in less than a decade, precipitating severe stadial conditions that lasted for hundreds or even thousands of years. These meltwater pulses are known as Heinrich events, named after the scientist who first recognized this cycle.

During Ice Ages warm stages of climate cyclically caused glacier dams to burst, releasing massive amounts of cold fresh water plus icebergs.  This shut down the North Atlantic Gulf Stream which brings tropically heated water north, resulting in a sudden decline in average annual temperatures.

A graph showing average annual temperature fluctuations over the last 100,000 years from data gleaned inside Greenland ice cores.  Cyclical Heinrich Events caused the sudden declines in temperatures.

I assumed Heinrich Events severely disrupted marine ecosystems, causing decisive population declines in most fish and other ocean fauna, though a few species may have benefitted from reduced competition or other factors.  But I thought there would be no paleontological evidence because preservation and detection of animal remains during brief time intervals in marine environments seemed unlikely.  However, a recent paper highlights evidence that Heinrich Events were detrimental to marine life.  Scientists found this evidence in a seaside Sicilian cave named la Grotta Dell’Uzzo.  This cave had previously revealed the Pleistocene remains of mammoth, rhino, lion, red deer, and wild boar.  Humans have also periodically occupied this cave from the late Pleistocene through the Holocene, and scientists have excavated human skeletons, artifacts, and food remains.  Chemical analysis of human bones found in the cave helped scientists determine the diet of the hunter-gatherers who occupied the cave during the early Holocene.  They ate red deer, wild boar, shellfish, fish caught near shore (such as grouper), acorns, grapes, and wild beans and peas.  However, 1 human specimen and 1 red fox bone, dating to 8200 BP, revealed an interesting difference. Both the human and the fox ate unusual quantities of whale meat during their lifetimes.  Red foxes don’t normally include whale meat in their diet, and humans from other generations of cave dwellers here hardly ever exploited this resource. Moreover, whale bones with butcher marks on them were found associated with the human and fox specimens in the same strata.  The scientists who examined this evidence determined humans exploited climate-driven whale strandings at this locality.

Mass stranding of pilot whales in Australia.  Heinrich Events disrupted marine ecology and caused high annual mortality among many species of whales.

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Evidence of early Holocene mass whale strandings was discovered in this seaside cave in Sicily, known as la grotto dell’Uzzo.

The last major Heinrich Event occurred 8200 years ago, following the final dissolution of glacial Lake Agassiz in Canada.  This massive meltwater pulse disrupted fish migrations and reduced fish populations, making it harder for many species of whales to find prey.  Stressed and malnourished whales are more likely to strand on beaches.  The Gulf of Castallammare, adjacent to la Grotto Dell’Uzzo, is an acoustic dead zone difficult for whales to navigate.  This is where frequent, probably annual, whale strandings occurred for centuries, and the evidence suggests humans and foxes exploited this resource.  Based on the zooarchaeological record, the most common species of whales stranded here were pilot whales (Globicephala melus), Risso’s dolphin ( Grampus griseus ), and short-beaked common dolphin ( Delphinus dolphio ). Frequent whale strandings likely occurred worldwide following Heinrich Events.  Off the coast of North America dire wolves, bears, and other large carnivores scavenged this wealth of protein during the Pleistocene.  There were certain spots, such as the 1 in Sicily, where carnivores learned to regularly search for this bounty.  Carnivore populations may have been higher near the coast due to this additional resource.  Unfortunately, evidence of these sites were long ago inundated by rising sea level.

Reference:

http://www.nature.com/articles/srep16288

Marcello, Mannino; at. al.

“Climate-driven Environmental Changes around 8200 Years Ago Favored Incidences of Cetacean Strandings and Mediterranean Hunter-Gatherers Exploited Them” 

Scientific Reports 2015

 

A Viable Scientific Explanation for why Africans Dominate Sports

September 10, 2015

Thomas Jefferson declared that “…all men were created equal…” Everybody knows this statement isn’t literally true.  When I was a little guy in grade school I wanted to become an NFL star.  Then I ran track in the 7th grade and much to my disappointment discovered there were many faster runners than me.  I knew I was too small and slow to ever make it as a professional football player.  Later in life, I wished I was 3 inches taller because I learned the chicks dig taller men.  Alas, I realized in some respects I was even less than average.

Thomas Jefferson didn’t actually mean all men were created equal, but he did believe all men should be treated equally under the law.  The subject of this blog entry is a touchy topic, so I want to make it clear that I agree with  the true meaning of Jefferson’s declaration, and I don’t believe in discriminating against people of varying races or religions.  I do not believe any race is superior to any other, though there are clear physical differences between races.  My essay is based on scientific facts published in peer-reviewed literature.  A scientific fact can not be considered racist or bigoted.

Athletes of African descent dominate running and jumping events in track, basketball, and certain positions in football such as running back, wide receiver, and defensive back.  There is not a single white cornerback in the NFL and only a handful of white running backs. This disparity can’t be explained by socio-economic factors alone.  While it is true that the average African-American family is economically poorer than the average white family, the total population of poor white people in America far outnumbers the total population of poor black people.  The pool of potential white participants who would like to escape poverty by playing basketball in the NBA or cornerback in the NFL is large but there are very few able to compete at that level due to a lack of natural ability.  There is an interesting and viable scientific explanation for this disparity.

Africa is the original birthplace of the human race.  Genetic studies show the original home of all species includes a more genetically diverse population.  After a new species evolves, they colonize new regions.  The populations that colonize new regions descend from the smaller gene pool that invaded the new territory. The history of Homo sapiens is an especially excellent illustration of this concept.  The ancestors of all Homo sapiens currently living on earth originally evolved in south Africa about 200,000 years ago.  About 60,000 years ago, a small population of humans left Africa and eventually the ancestors of this group spread throughout the world.  The entire population of Europeans, Asians, and Australian aborigines descend from just 1 or a few tribes that left Africa long ago.  This means Africans are more genetically diverse than the people who colonized the rest of world.  There is more genetic diversity in an African village of 70 people than there is in all of China.

The Khomani bush people of south Africa are the oldest race known.  Scientific studies show they are genetically the most diverse people in the world.  All of humanity descends from their ancestors.  Photos of Khomanis are remarkable.  Of course, they all have dark skin, but their facial features show a wide variation.  Some look Caucasian, some look Asian, and some have Negro features.

Khomani African Bushmen are genetically the oldest human race.  Their ancestors are the ancestors of tribes that gave birth to other Africans, Caucasians, and Asians.  Facial features within this tribe vary–some look Asian, others Negroid, and some resemble Caucasian.  Note the woman on the left.  She looks Asian, while the baby has Negroid features.

These Khomani children could almost pass for white.

As the descendants of the Khomani colonized the rest of Africa, the various tribes became geographically isolated.  Humans evolved in Africa for 140,000 years before any left the continent, so the overall population on this continent remained genetically more diverse than the human populations in the rest of the world.  This genetic diversity meant extremes in various body types were more pronounced in Africa than in Europe and Asia.  For example 7 foot tall Watusi tribesmen lived within miles of 4 foot tall pygmies.  Studies show that people who lived in west Africa evolved (on average) an higher ratio of fast twitch muscle fibers than any other population of people.  This made them extraordinary sprinters and jumpers.  This explains why all cornerbacks in the NFL  and most Olympic sprinters are of west African descent.   Studies show that people living in east Africa evolved the ability to produce more energy producing enzymes.  This helps with long distance running and explains why Kenyans are dominating marathon running.

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Pygmy tribes live just a few miles from the very tall Watusis, demonstrating the amount of genetic diversity in Africa.  You won’t find any pygmies in the NFL or NBA.  Almost all African-Americans in those sports leagues are of west African descent located to the northwest of pygmy tribal areas.

finish line in men's 100 meters at olympics

The average human of West African descent has an higher ratio of fast twitch muscle fibers than other humans.  This explains why people of West African descent dominate sprinting, basketball, and certain positions in football such as running back, receiver, and defensive back.

Studies have also found that the average African has a greater bone density than the average white person.  This durability aids in contact sports.  Africans have a much lower rate of developing osteoporosis and hip fractures.  African women are less than half as likely to suffer hip fractures when they get older than white women.  They are even less likely to get hip fractures than white men.  However, this greater bone density is a disadvantage in competitive swimming.

Note: None of these minor physiological differences are related to intelligence in anyway.

References:

Entine, Jon

Taboo: Why Black Athletes Dominate Sports and why We’re Afraid to Talk About it

Public Affairs 2000

Henn, Brenna; et. al.

“Hunter-gatherer Genome Diversity Suggests a Southern African Origin for Modern Man”

PNAS 2011

Hockberry, Marc

“Racial Differences in Bone Structure”

Transactions of American Clinical Climatological Annual 2007

Survival of the Fittest and Dwarfism–A Paradox

September 4, 2015

The concept of natural selection forms the basis for the Theory of Evolution.  Environmental forces select the fittest members of each population to pass on their genes.  Most people think survival of the fittest means selecting the biggest, fastest, and strongest; and that is often true.  However, insular evolution (the evolution of species on islands) shows that survival of the fittest can mean the opposite as well.  During the Pleistocene many species of megafauna became stranded on islands.  Islands are often devoid of large predators.  Megafauna evolved to a greater size in response to predation, so without the presence of predators, there was no longer selective pressure toward a larger size.  Smaller individuals were just as likely to survive.  Moreover, these smaller individuals had an advantage on islands where less food was available.  On continents megafauna could migrate to different regions when forage became scarce, but they didn’t have this luxury on islands.  Smaller individuals were more likely to survive during times of scarcity because they required less food.  This explains the tendency toward dwarfism among Pleistocene megafauna that lived on islands.

During the Pleistocene there were 8 species of dwarf ground sloths living on Cuba, 7 on the island of Hispaniola, and 1 on Puerto Rico.  Megaloncus rodens was 1 of the species that lived on Cuba, and it grew to 200 pounds.  By contrast the smallest species of continental ground sloth grew to 500 pounds.  Dwarf ground sloths survived in the Caribbean until as recently as 4700 BP, about 1200 years after humans colonized the region.  Humans must be responsible for their extinction because there was no major climatic change during this time period.

Skeletal mount of Caribbean dwarf ground sloth (Megalocnus rodens) next to a paleontologist in 1920.  All continental species of ground sloths were larger than men.

Full-sized Columbian mammoths (Mammuthus colombi) swam to the Channel Islands off the coast of California and eventually evolved into a dwarf species known as Mammuthus exilis.  Evidence suggests they arrived as early as 250,000 years BP and survived 2 complete glacial/interglacial cycles but became extinct when men found the island.  The late surviving population of mammoths living on Wrangel Island off the Alaskan coast were not a dwarf species, but those living on St. Paul’s Island off Alaska were.

Each island in the Mediterranean Sea had its own species of dwarf elephant or mammoth.  Dwarf elephants lived on Cyprus, Malta, Sicily, Sardinia, and Stylus (now underwater).  Dwarf mammoths lived on Crete.  Every time sea level fell in response to glacial expansion, new waves of elephants colonized these islands, and all evolved into dwarf species.  Distances were shorter between the mainland and the islands during glacial expansions, and it was easier for these large animals to swim there.  Some of these dwarf species were still large animals, weighing as much as 500 pounds, but others reached heights of just 3 feet tall.

Size comparison between human, full sized elephant, and 2 different species of dwarf elephants.

Some Mediterranean islands also hosted populations of dwarf hippos.  Sicily, Malta, Crete, and Cyprus were home to 4 different species of dwarf hippos respectively.  There were 3 different species of dwarf hippo living on Madagascar until 1000 years ago when humans wiped them out.

Hippo in Middle~Late Pleistocene Mammalian by sinammonite

Artist’s depiction of extinct Mediterranean dwarf hippos.  P. minor lived on Cyprus, H. melitensis lived on Malta, H. creutzburgi lived on Crete, and H. pentlandi lived on Sicily.

Stegodon floresiensis insularis was a dwarf species of elephant that lived on the Indonesian island of Flores.  It shared the island with a dwarf hominid, Homo floresiensis, known famously as the hobbit.  This hominid likely evolved from Homo erectus, but in isolation from the parent population became a dwarf species.  The hobbit grew to 3.5 feet tall and had the brain capacity of a chimpanzee.  Nevertheless, the area of their brain associated with language was well developed, and they may have been as intelligent as modern humans because their ratio of brain capacity to body size was similar.  They hunted dwarf stegodons.  Komodo dragons and even marabou storks were a threat, especially to juvenile hobbits.  Homo floresiensis lived as recently as 14,000 BP.

Artist’s depiction of real life hobbits (Homo floresiensis) battling marabou storks on the Indonesian island of Flores.

Ground sloths, elephants, and hippos were/are excellent long distance swimmers.  That explains how they colonized islands.  The ancestors of the hobbit either built rafts or accidentally rafted to the island on flood debris.  If they built rafts, they may have forgotten the technology after several generations.

There are over 200 medical causes of dwarfism, and some traits that cause it can be inherited.  A human dwarf is defined as an adult less than 4’10” in height.  Some kinds of dwarfism in children can be treated with growth hormones and drugs that stimulate appetite.  Parents fear their children will face societal prejudice, if they don’t reach a “normal” height.  Few realize the trait for dwarfism could potentially be favorable for natural selection, if environmental conditions on earth deteriorate.  The traits that favor future survival of the fittest on this island earth can’t be predicted.

What happened when James Lusted, who stands just 3ft 7in tall, took his fiancee for a romantic meal at a Harvester in Cardiff?

If the world suffered a severe shortage of food for millennia, human evolution would tend toward dwarfism.  Humans with smaller body size have an  advantage in environments with less food.

References:

Muhs, Daniel; et. al.

“Late Quaternary Sea-Level History and the Antiquity of Mammoths (M. exilis and M. colombi) on the Channel Islands National Park, California, USA”

Quaternary Science Review May 2015

Poulakatis, Nikos; et. al.

“Ancient DNA Forces Reconsideration of Evolutionary History of Mediterranean Pygmy Elephants”

Biology Letters 2006

The Shrinking Brain

July 5, 2015

Humans (Homo sapiens), like all other organisms, are continuously evolving, and the forces that shape human evolution have also changed.  Before the development of agriculture, ecological pressures were the primary influence on human evolution.  Human populations were scattered and low.  Each individual had to work and think harder then because survival in primitive environments required greater endurance and intelligence.  Pleistocene Homo sapiens had to do it all.  On average Cro-magnon man, also known as European early modern humans, had larger jaws and teeth, a bigger lung capacity, and a larger cranial capacity than present day man.  The average cranial capacity of a human being living 20,000 years ago was 1500 cubic centimeters compared to 1350 cubic centimeters for an average human today.  This larger brain capacity does mean they were more intelligent, but of course lacked our present day knowledge.  During the agricultural revolution social competition replaced ecological processes as the primary influence on human evolution.  This led to a division of labor, reducing the need for such a large cranial capacity.  Human intelligence has declined all over the world since.

Shrinking Brain in Humans

Modern humans have a smaller brain capacity than their recent ancestors.  Incidentally, this illustration is misleading.  Homo sapiens did not evolve from Neanderthals.  Instead, Homo sapiens and Homo neandethalis shared a common ancestor–Homo heidelbergensis. Homo Neanderthals were also a distinct species, not a subspecies.

Domesticated cattle, sheep, goats, and dogs also have smaller cranial capacities than their wild ancestors.  Humans culled the larger, wilder individuals; creating tamer breeds.  Humans culled people who didn’t conform to society’s rules as well.  In this way humans may have eliminated many people with larger brains that just couldn’t fit in.  One study of a primitive society in New Guinea showed that as much as 10% of the males were executed because they couldn’t follow society’s rules.  The death penalty selects for tamer humans by eliminating aggressive individuals from the gene pool.  The death penalty was also common in western societies until the 20th century.

Aggressive intelligent humans had a big advantage over tame humans when the world was a wild place.  But some of the characteristics that favored survival in a wilderness are counterproductive in a civilization  dependent upon the rule of law to prevent chaos.

Human cranial capacity is on the increase again.  Over the past 200 years there has been a major improvement in the average human’s diet.  Better nutrition is leading to larger cranial capacities.  The brain is a large fatty organ that requires a great deal of energy.  With a better food supply humans with large brains are more likely to survive.  However, I believe this recent trend is temporary.  I predict future generations will suffer from greater incidences of malnutrition as the world population outstrips the ability of farmers to produce enough food for everybody.

References:

Bailey, Drew; and David Geary

“Hominid Brain Evolution: Testing Climatic, Ecological, and Social Competition Models”

Human Nature 2009

McAuliffe, Kathleen

“If Modern Humans are so Smart, why are our Brains Shrinking?”

Discover Magazine 2010

How to sell Books with a Misleading Premise

June 30, 2015

I finished reading The Invaders: How Humans and their Dogs Drove Neanderthals to Extinction by Pat Shipman, and it left me shaking my head in confusion.  The author debunked the title of her book on page 213 when she wrote “…there are no well-dated Neanderthal sites younger than about 40,000 years ago; all are older.  Unless future finds show wolf-dogs in even earlier sites, Neanderthals were extinct by the time wolf-dogs appeared.”  If Neanderthals were extinct by the time humans supposedly began working with “wolf-dogs,” the human-dog connection can’t possibly be the reason Neanderthals became extinct.  I think the author invented a sensationalist title to sell copies of a book that is based on a completely unfounded premise.  Perhaps it was the publisher’s idea.  The last chapter of this book seems to be an incoherent add-on.

The Invaders: How Humans and Their Dogs Drove Neanderthals to Extinction

The author of this book convincingly refutes her own premise.

The premise of her book depends upon 1 highly controversial study.  This study used a complex statistical analysis of dog and wolf skull measurements to differentiate between the 2.  These scientists measured a skull from Goyet Cave, Belgium; dating to 36,000 calendar years BP, and determined it had a 99% chance of being from a dog.  Prior to this find, it was thought humans didn’t domesticate dogs until about 14,000 BP.  Some other canid skulls measured in this study, dating to older than 14,000 BP, were also determined to be dog rather than wolf.  However, another study (referenced below) completely contradicts this conclusion.  These scientists used a 3-D morphometric analysis of the same ancient canid skulls and determined the Goyet Cave specimen and others of similar age were wolf, not dog.  A DNA study of these specimens determined these particular canids were not ancestral to modern dogs or extant wolves.  They were probably just an extinct ecomorph of wolf.  Alas for Pat Shipman, her hypothesis is a poorly reasoned fantasy.

Humans didn’t need dogs to rub out Neanderthals.  Humans likely had far superior organizational skills as well as advanced technology such as projectile weapons and knitting needles.  Humans could survive in a colder climate with better clothing and could successfully hunt animals on open plains.  I’m certain humans beat Neanderthals in battle by using strategy and tactics.  I do think humans were the sole factor in the extinction of Neanderthals.  If Homo sapiens never colonized Europe, Neanderthals would still be there today.  Climate change can’t be the reason for their extinction because Neanderthals survived dozens of dramatic shifts in climate phases during their >250,000 year occupation of Europe.

I found a couple of other minor mistakes in The Invaders worth noting.  This isn’t a big deal–I know there are mistakes on my blog, but I’m too lazy to go back and edit corrections.  The late surviving population of mammoths on Wrangel Island lasted until 4000 BP, not 3000 BP, and they were not a dwarf population as Pat Shipman mistakenly claimed.  They were fully-sized woolly mammoths (Mammuthus primigenius).  She also reproduced a graph in her book from a study that mistakenly classifies the aurochs (Bos taurus), the ancestor of modern cattle, as a steppe environment inhabitant.  The aurochs favored habitat was riparian woodland.  Cattle need frequent access to water and are not well adapted to arid grassland habitat.

Reference:

Drake, Abby; et. al.

“3D Morphometric Analysis of Fossil Canid Skulls Contradicts Domestication of Dogs during the Late Paleolithic”

Scientific Reports 2015