"When Alligators Roamed the Arctic" --Big Global Change 34-Million Years Ago Shows Shift from Greenhouse Age to Ice Age

The image above shows how North America appeared in the Eocene Epoch,33.9 - 55.8 million years ago. Earth's climate was warm relative to today. Polar ice sheets were smaller and sea level was higher. The climate in Nebraska was warm and humid, but began to cool and become more arid toward the end of the epoch Eocene. To the west, the Rocky Mountains continued to form. Sediment shed from the uplifting mountains was carried eastward by river systems and deposited in Nebraska.

The dominant factors in the rise and fall of the diversity of life on Earth has been a point of debate for scientists nearly as long as they have studied the processes of evolution. In the 1970s, evolutionary biologist Leigh Van Valen began calling the case for biological factors (such as competition with other organisms for food, space and mates) the "Red Queen" hypothesis, after Lewis Carroll's "Through the Looking-Glass" character who tells Alice she must run hard in Wonderland just to stay in the same place. The alternative argument, backing the nonbiological forces of the environment (physical characteristics like chemistry and temperature or relative catastrophes like asteroid impacts), came to be known as the "Court Jester" hypothesis.

"This question—which one is pulling the strings?—is a big one for people who study the history of life on Earth," says Shanan Peters, a University of Wisconsin–Madison geoscience professor. "And what we've found is that it's actually both. They just play very different roles."
Peters and Clay Kelly, a fellow UW–Madison geoscience professor, chose to pit the Red Queen and Court Jester against each other on the high seas, over planktonic foraminifera: tiny, shelled, ocean-dwelling creatures with an outsized impact on the planet and science. Read More

Researchers conclude that climate change led to collapse of ancient Indus civilization

"A new study combining the latest archaeological evidence with state-of-the-art geoscience technologies provides evidence that climate change was a key ingredient in the collapse of the great Indus or Harappan Civilization almost 4000 years ago. The study also resolves a long-standing debate over the source and fate of the Sarasvati, the sacred river of Hindu mythology."

Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest—but least known—of the first great urban cultures that also included Egypt and Mesopotamia. Like their contemporaries, the Harappans, named for one of their largest cities, lived next to rivers owing their livelihoods to the fertility of annually watered lands.
"We reconstructed the dynamic landscape of the plain where the Indus civilization developed 5200 years ago, built its cities, and slowly disintegrated between 3900 and 3000 years ago," said Liviu Giosan, a geologist with Woods Hole Oceanographic Institution (WHOI) and lead author of the study published the week of May 28 in the Proceedings of the National Academy of Sciences. "Until now, speculations abounded about the links between this mysterious ancient culture and its life-giving mighty rivers."
Today, numerous remains of the Harappan settlements are located in a vast desert region far from any flowing river. In contrast to Egypt and Mesopotamia, which have long been part of the Western classical canon, this amazingly complex culture in South Asia with a population that at its peak may have reached 10 percent of the world's inhabitants, was completely forgotten until 1920's. Since then, a flurry of archaeological research in Pakistan and India has uncovered a sophisticated urban culture with myriad internal trade routes and well-established sea links with Mesopotamia, standards for building construction, sanitation systems, arts and crafts, and a yet-to-be deciphered writing system. Read More

Penn Anthropologists Clarify Link Between Asians and Early Native Americans

[This fascinating article correlates information in the upcoming third book in the Golden City Series, Divine Destiny. Look for this new release in the next month.--Lori]

A tiny mountainous region in southern Siberia may have been the genetic source of the earliest Native Americans, according to new research by a University of Pennsylvania-led team of anthropologists.
Lying at the intersection of what is today Russia, Mongolia, China and Kazakhstan, the region known as the Altai “is a key area because it’s a place that people have been coming and going for thousands and thousands of years,” said Theodore Schurr, an associate professor in Penn’s Department of Anthropology. Schurr, together with doctoral student Matthew Dulik and a team of graduate students and postdoctoral researchers, collaborated on the work with Ludmila Osipova of the Institute of Cytology and Genetics in Novosibirsk, Russia.
Among the people who may have emerged from the Altai region are the predecessors of the first Native Americans. Roughly 20-25,000 years ago, these prehistoric humans carried their Asian genetic lineages up into the far reaches of Siberia and eventually across the then-exposed Bering land mass into the Americas.
“Our goal in working in this area was to better define what those founding lineages or sister lineages are to Native American populations,” Schurr said.
The team’s study, published in the American Journal of Human Genetics, analyzed the genetics of individuals living in Russia’s Altai Republic to identify markers that might link them to Native Americans. Read More

Neanderthals' demise caused by modern human invasion

[This article parallels research featured in our upcoming book from I AM America Publishing Divine Destiny, the second volume from the Golden City Series. Look for Divine Destiny this fall!]

by Ian Sample
Neanderthals died out in Western Europe after a surge of modern humans arrived from Africa and made them a minority in their own land, researchers claim.

The swarm of Homo sapiens onto the continent more than 40,000 years ago left the Neanderthals, who had thrived in the frigid conditions for 300 millennia, outnumbered by a massive 10 to one. The invasion of so many modern humans overturned the Neanderthals' domination of the land and forced them into fierce competition for food, fuel and other crucial resources. The scenario, described by Paul Mellars, emeritus professor of prehistory and human evolution at Cambridge University, and his colleague, Jennifer French, is the latest attempt by scientists to explain the mystery of the Neanderthals' demise. Read More