Posts Tagged ‘Homo erectus’

Middle Pleistocene Man (Homo heidelbergensis)

January 29, 2021

Many late Pleistocene animals evolved from middle Pleistocene ancestors that were different enough to be considered separate species.  Columbian mammoths (Mammuthus colombi) evolved from the southern mammoth (M. meridionalis), a shorter elephant with straighter tusks. Jefferson’s ground sloth (Megalonyx jeffersoni) evolved from Wheatley’s ground sloth (M. wheatleyi), and Smilodon fatalis evolved from the more lightly built S. gracilis, among many other examples.  The same is true for humans.  Both Homo sapiens and H. neanderthalis evolved from H. heidelbergensis, also known as Heidelberg man after discovery of the first specimen in Heidelberg, Germany during 1907.  Genetic evidence suggests modern humans diverged from Neanderthals between 750,000 years BP-550,000 years BP.  The population of Heidelberg man that lived in Europe evolved into H. neanderthalis, while the population of Heidelberg man that lived in Africa evolved into H. sapiens.  (The poorly known Denisovans diverged from Neanderthals.) Fossil evidence of Heidelberg man dates to between 600,000 years BP-300,000 years BP, though undoubtedly it occurred earlier than the fossil evidence indicates.  The oldest evidence of humans in Europe dates to 800,000 years ago and was found in Spain, but these specimens are considered an extinct sister species of Heidelberg man known as H. ancessor.

Homo Heidelbergensis: Forbears of Homo Sapiens - The Human Journey

Artist’s depiction of Homo heidelbergensis.  They were about the same height as modern men and had the same average brain capacity, but their jaws were distinctly different.

New insights on the wooden weapons from the Paleolithic site of Schöningen - ScienceDirect

The Schoningen spears, 330,000 year old projectile weapons used by Homo heidelbergensis.  They were found in a strip mine in Germany.  Archaeologists found 9 spears, 1 lance, a stick pointed on both ends, and a burned stick along with the remains of butchered horses next to a lakeshore.

Heidelberg man evolved from H. erectus.  Heidelberg man had a more human-like face and a larger brain capacity (averaging 1200 cc compared to 973 cc).  They had the same average brain size as modern day humans, and the main difference between the 2 is the shape of the jaw which was distinct.  Heidelberg man was the first species of human to colonize regions with cold climates.  To survive in harsher climates, they evolved to eat more meat.  In Europe this diet included elephant, rhino, bear, deer, boar, and horse; and in Africa they ate antelope and zebra.  They surely ate many different kinds of plants, but nothing is known of the vegetal part of their diet.  Heidelberg man had control of fire and used tools such as stone hand axes and wooden spears. In 1994 nine spears made of spruce wood were found in a German strip mine, and they dated to 330,000 years BP.  They are known as the Schoningen spears, and they were found associated with butchered horse bones.  Rapid rise of a lake level covered all this evidence in sediment and helped preserve it.

I have no doubt Heidelberg man could speak, though a minority of scientific opinion believes they could not.  The hyoid bone, important for speech, is well developed as are the middle ear bones used for understanding speech.  There is also evidence for right brain/left brain lateralization–one side of the brain is more dominant.  Brain lateralization suggests a brain used to speak and understand speech.  Heidelberg man hunted large mammals, an activity requiring cooperative hunting and therefore speech.

Specimens of Heidelberg man have been found in sites located in Germany, England, France, Greece, India, Zambia, Kenya, Ethiopia, and South Africa.  I tried to find out exactly how many specimens have been discovered worldwide, but as far as I can determine no study has catalogued them all.

Heidelberg man likely occurred in low population numbers, fluctuating with boom and bust climatic conditions, and whole tribes often perished  when important members died.  One site in Germany where Heidelberg remains were found also yielded bones of saber-tooths (Homotherium), lions, leopards, hyenas, bear, elephant, red deer, and horse.  Unlike modern humans, Heidelberg man didn’t always win in competition with the predators they shared the landscape with.

Reference:

Schoch, W.; G. Bigga, W. bohner, P. Richter, and T. Terberger

“New Insights on the Wooden Weapons from the Paleolithic Site of Schoningen”

Journal of Human Evolution 89 December 2015

The Galerian Migration hypothesis

February 25, 2018

During the middle Pleistocene the faunal diversity of Europe increased.  Scientists attribute this to glacial/interglacial transitions that changed the environment, transforming it from forest to grassland and savannah.  Forests were restricted to narrow corridors along rivers and upper elevations.  Cooling temperatures and aridity caused these changes.  Animals from Africa and Asia colonized the open savannahs that became established along the Danube and Po River valleys.  Red deer, atlas deer, wild boar, bison, aurochs, an extinct species of Indian water buffalo (Hemibos galerianus), and horses invaded from Asia.  An extinct species of temperate-adapted elephant (Elephas antiquus), mammoth (Mammuthus trogontherii), rhino, lion,  leopard, spotted hyena, and Homo erectus came from Africa.  The Galerian Migration Hypothesis posits archaic humans first colonized Europe during this time period because they were a part of this savannah ecosystem, and they used the same route as their contemporaries in the animal world.

Image result for map of Danube, River

Map of the Danube River.  The Po River goes through northern Italy.  The Galerian Migration Hypothesis proposes archaic humans first entered Europe through savannahs in these 2 river valleys.

Data from magnetstratigraphy supports the Galerian Migration Hypothesis.  Scientists can date objects based on which direction the magnetic minerals within associated rocks are oriented.  The earth’s polarity has shifted periodically throughout history, causing magnetic minerals in rocks to point in certain directions.  Scientists calibrate changes in polarity with radiometric dating, so magnetstratigraphy provides useful parameters.  Scientists know from magnetstratigraphy that Homo erectus probably first colonized Europe between 780,000 years BP-990,000 years BP. The oldest  Homo erectus fossil known from Europe falls within these dates. These dates correspond well with environmental changes, and changes in faunal composition.  Homo erectus originated in Africa and colonized Asia and the Middle East as early as 1.9 million years ago, but there was a delay before they reached Europe.

The invasion of humans and spotted hyenas likely drove the extinction of hyena species already in Europe–Pachycrocuta breverosti and Pliocrocuta perra.  The newcomers outcompeted the native hyenas for the narrow hunter/scavenger niche.

During full glacial maximums southern Italy and Spain served as refuges for species such as Elephas antiquus and a temperate-adapted species of rhino.  However, during the Last Glacial Maximum, the superior hunting humans (Homo sapiens) probably overhunted these species to extinction in their glacial refugia.

Reference:

Muttoni G.; Giancarlo Scardio, and Dennis Kane

“Early Hominins in Europe: The Galerian Migration Hypothesis”

Quaternary Science Review 180 Jan 2018