Neanderthals walked upright just like the humans of today

Neanderthals are often depicted as having straight spines and poor posture. However, these prehistoric humans were more similar to us than many assume. University of Zurich researchers have shown that Neanderthals walked upright just like modern humans — thanks to a virtual reconstruction of the pelvis and spine of a very well-preserved Neanderthal skeleton found in France.

Neanderthals walked upright just like the humans of today
Virtual reconstruction of the skeleton found in La Chapelle-aux-Saints, based on high-resolution
3D surface scans of the spine and pelvis [Credit: Martin Häusler, UZH]

An upright, well-balanced posture is one of the defining features of Homo sapiens. In contrast, the first reconstructions of Neanderthals made in the early 20th century depicted them as only walking partially upright. These reconstructions were based on the largely preserved skeleton of an elderly male Neanderthal unearthed in La Chapelle-aux-Saints, France.

Changing perspectives

Since the 1950s, scientists have known that the image of the Neanderthal as a hunched over caveman is not an accurate one. Their similarities to ourselves — both in evolutionary and behavioral terms — have also long been known, but in recent years the pendulum has swung in the opposite direction. «Focusing on the differences is back in fashion,» says Martin Haeusler, UZH specialist in evolutionary medicine. For instance, recent studies have used a few isolated vertebrae to conclude that Neanderthals did not yet possess a well-developed double S-shaped spine.

However, a virtual reconstruction of the skeleton from La Chapelle-aux-Saints has now delivered evidence to the contrary. This computer-generated anatomical model was created by the research group led by Martin Haeusler from the University of Zurich and included Erik Trinkaus from Washington University in St. Louis. The researchers were able to show that both the individual in question as well as Neanderthals in general had a curved lumbar region and neck — just like the humans of today.

Sacrum, vertebrae and signs of wear as evidence

When reconstructing the pelvis, the researchers discovered that the sacrum was positioned in the same way as in modern humans. This led them to conclude that Neanderthals possessed a lumbar region with a well-developed curvature. By putting together the individual lumbar and cervical vertebrae, they were able to discern that the spinal curvature was even more pronounced. The very close contact between the spinous processes — the bony projections off the back of each vertebra — became clear, as did the prominent wear marks that were in part caused by the curvature of the spine.

Recognizing similarities

Wear marks in the hip joint of the La Chapelle-aux-Saints skeleton also pointed to the Neanderthals having an upright posture similar to that of modern humans. «The stress on the hip joint and the position of the pelvis is no different than ours,» says Haeusler. This finding is also supported by analyses of other Neanderthal skeletons with sufficient remnants of vertebrae and pelvic bones. «On the whole, there is hardly any evidence that would point to Neanderthals having a fundamentally different anatomy,» explains Haeusler. «Now is the time to recognize the basic similarities between Neanderthals and modern humans and to switch the focus to the subtle biological and behavioral changes that occurred in humans in the late Pleistocene.»

The study is published in the Proceedings of the National Academy of Sciences.

Source: University of Zurich [February 25, 2019]

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2019 February 25 Red Sprite Lightning over Kununurra Image…

See Explanation.  Clicking on the picture will download
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2019 February 25

Red Sprite Lightning over Kununurra
Image Credit & Copyright: Ben Broady

Explanation: What are those red filaments in the sky? It is a rarely seen form of lightning confirmed only about 30 years ago: red sprites. Recent research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light and are quickly followed by a group of upward streaking ionized balls. The featured image, taken just over a week ago in Kununurra, Western Australia, captured some red sprites while shooting a time-lapse sequence of a distant lightning storm. Pictured, green trees cover the foreground, dark mountains are seen on the horizon, ominous storm clouds hover over the distant land, while red sprites appear in front of stars far in the distance. Red sprites take only a fraction of a second to occur and are best seen when powerful thunderstorms are visible from the side.

∞ Source: apod.nasa.gov/apod/ap190225.html

This footage from the ISS shows a red sprite over East Asia at around 0:06.

A sprite over Laos, as seen from the International Space Station
A sprite over Laos, as seen from the International Space Station

 

Ancient poop helps show climate change contributed to fall of Cahokia

A new study shows climate change may have contributed to the decline of Cahokia, a famed prehistoric city near present-day St. Louis. And it involves ancient human poop.

Ancient poop helps show climate change contributed to fall of Cahokia
A painting of Cahokia Mounds State Historic site by William R. Iseminger. Horseshoe Lake, where core sediments
 give a timeline of flooding from the Mississippi River, can be seen in the upper left
[Credit: William R. Iseminger]

Published in the Proceedings of the National Academy of Sciences, the study provides a direct link between changes in Cahokia’s population size as measured through a unique fecal record and environmental data showing evidence of drought and flood.

«The way of building population reconstructions usually involves archaeological data, which is separate from the data studied by climate scientists,» explains lead author AJ White, who completed the work as a graduate student at California State University, Long Beach. «One involves excavation and survey of archaeological remains and the other involves lake cores. We unite these two by looking at both kinds of data from the same lake cores.»

Last year, White and a team of collaborators — including his former advisor Lora Stevens, professor of paleoclimatology and paleolimnology at California State University, Long Beach, and University of Wisconsin-Madison Professor of Anthropology Sissel Schroeder — showed they could detect signatures of human poop in lake core sediments collected from Horseshoe Lake, not far from Cahokia’s famous mounds.

These signatures, called fecal stanols, are molecules produced in the human gut during digestion and eliminated in feces. As the people of Cahokia pooped on land, some of it would have run off into the lake. The more people who lived and defecated there, the more stanols evident in lake sediments.

Because the sediments of a lake accumulate in layers, they allow scientists to capture snapshots of time throughout the history of a region through sediment cores. Deeper layers form earlier than layers found higher up, and all of the material within a layer is roughly the same age.

White found that fecal stanol concentrations at Horseshoe Lake rise and fall similarly to estimates of Cahokia’s population from better-established archaeological methods.

Ancient poop helps show climate change contributed to fall of Cahokia
A modelled map of Cahokia and present-day St. Louis after the historic 1844 flood of the Mississippi River
[Credit: Samuel Munoz]

Schroeder, a scholar of the Cahokia area, says that excavations of the houses in and near Cahokia show human occupation of the site intensified around A.D. 600, and by 1100, the six-square-mile city reached its peak population. At the time, tens of thousands of people called it home.

Archaeological evidence also shows that by 1200, Cahokia’s population was on the decline and the site was abandoned by its mound-building Mississippian inhabitants by 1400.

Scientists have uncovered a number of explanations for its eventual abandonment, including social and political unrest and environmental changes.

For instance, in 2015, co-author Samuel Munoz, a former UW-Madison graduate student and now a professor at Northeastern University, was actually the first to collect one of the Horseshoe Lake sediment cores White used in his study and he found evidence that the nearby Mississippi River flooded significantly around 1150.

White’s latest study ties the archaeological and environmental evidence together.

«When we use this fecal stanol method, we can make these comparisons to environmental conditions that hither to now we haven’t really been able to do,» says White, now a PhD student at UC Berkeley.

Using Munoz’s core and another White collected on Horseshoe Lake, the research team measured the relative amount of fecal stanols from humans present in sediment layers. They compared these to stanol levels known to come from bacteria in the soil in order to establish a baseline concentration for each layer.

Ancient poop helps show climate change contributed to fall of Cahokia
Cahokia region and Horseshoe Lake watershed, shown as the black dashed line. Dark brown colors indicate higher
topography, principally the river bluffs, and the yellow indicates the Mississippi River floodplain. Coring sites
are indicated by red stars. The Cahokia complex is approximated by the large circle around black rectangles
showing the position of some of the mounds at the site. Black dots show the locations of other sites with mounds
within the Horseshoe Lake watershed that were occupied contemporaneously with Cahokia [∼1000–1400 CE].
Base map elevation data are derived from the National Elevation Dataset
[Credit: A.J. White el al. 2019]

They examined the lake cores for evidence of flooding and also looked for climate indicators that would inform them whether climate conditions were relatively wet or dry. These indicators, the ratio of a heavy form of oxygen to a light one, can show changes in evaporation and precipitation. Stevens explains that as water evaporates, the light form of oxygen goes with it, concentrating the heavy form.

The lake core showed that summer precipitation likely decreased around the onset of Cahokia’s decline. This could have affected the ability of people to grow their staple crop maize.

A number of different changes begin to happen in the archaeological record around 1150, Schroeder explains, including the number and density of houses and the nature of craft production.

These are all indicators of «some kind of socio-political or economic stressors that stimulated a reorganization of some sort,» she says. «When we see correlations with climate, some archaeologists don’t think climate has anything to do with it, but it’s difficult to sustain that argument when the evidence of significant changes in the climate shows people are facing new challenges.»

This has resonance today, she adds.

«Cultures can be very resilient in face of climate change but resilience doesn’t necessarily mean there is no change. There can be cultural reorganization or decisions to relocate or migrate,» Schroeder says. «We may see similar pressures today but fewer options to move.»

For White, the study highlights the nuances and complications common to so many cultures and shows how environmental change can contribute to social changes already at play.

Author: Kelly April Tyrrell | Source: University of Wisconsin-Madison [February 25, 2019]

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