Another clue to American Origins

http://m.bbc.com/news/science-environment-27432234

This theory argues that people from Siberia settled on the land bridge dubbed Beringia that linked Asia and the Americas some 20,000 years ago before sea levels rose.

These people then moved south to populate the American continents.

The genetics of modern Native Americans would certainly appear to link them into this story. But their facial features set them apart from the oldest skeletons now being unearthed.

These ancient people had narrower,longer skulls. The differences have hinted that perhaps there were multiple immigrations from Siberia (or even Europe).

Evolution link

However,the remains of the Yucatan girl,dubbed Naia - which means "water nymph" in Greek - does not follow that line of thinking,because although she had the slender features associated with the earliest Americans,her DNA shares commonalities with modern Native Americans.

Lab analysis of teeth and bone samples link her to a particular genetic lineage known as Haplogroup D1.

This same marker is found in substantial numbers of modern Native Americans.

"This lineage is thought to have developed in Beringia,the land that now lies beneath the Bering Sea after its ice age occupants became genetically isolated from the rest of Asia," explained lead author Dr Jim Chatters.

"Thus,Naia,one of the earliest occupants of the Americas yet found, suggests that Paleoamericans do not represent an early migration from a part of the world different than that of the Native Americans.

"Rather,Paleoamericans and Native Americans descended from the same homeland in Beringia.

"The differences between them likely arose from evolution that occurred after the Beringian gene pool became separated from the rest of the world."

'Died almost instantly'

Scientists can only speculate as to why Naia had been in the cavern. Skeletal remains of many animals also litter the pit's floor.

The suspicion is that they all were looking for water, because the region had a very dry climate 12,000 years ago and the cavern would have been mostly dry but for a few pools.

Perhaps they stumbled and fell to their death in the darkness.

"Her pelvis is broken and it appears to have been broken at or around the time of her death because it's fractured in a way that relatively young bone would break rather than ancient bone," said Dr Chatters.

"So,it appears she fell quite a distance and struck something hard. I think she died almost instantly,if not instantly."

Fascinating!

Beringia is a loosely defined region surrounding the Bering Strait, the Chukchi Sea, and the Bering Sea. It includes parts of Chukotka and Kamchatka in Russia as well as Alaska in the United States. In historical contexts it also includes the Bering land bridge, an ancient land bridge roughly 1,000 miles (1,600 km) wide (north to south) at its greatest extent, which connected Asia with North America at various times during the Pleistocene ice ages.

The term Beringia was first coined by the Swedish botanist Eric Hultén in 1937.[1] During the ice ages, Beringia, like most of Siberia and all of Manchuria, was not glaciated because snowfall was very light.[2] It was a grassland steppe, including the land bridge, that stretched for several hundred miles into the continents on either side. It is believed that a small human population of at most a few thousand survived the Last Glacial Maximum in Beringia, isolated from its ancestor populations in Asia for at least 5,000 years, before expanding to populate the Americas sometime after 16,500 years ago, during the Late Glacial Maximum as the American glaciers blocking the way southward melted.[3][4][5][6]

Prior to European colonization Beringia was inhabited by the Yupik peoples on both sides of the straits. This culture remains in the region today along with others.

During the last glacial period, enough of the earth's water became frozen in the great ice sheets covering North America and Europe that the corresponding drop in sea levels exposed the sea floors of many interglacial shallow seas for thousands of years, including those of the Bering Strait, the Chukchi Sea to the north, and the Bering Sea to the south. Other land bridges around the world have emerged and disappeared in the same way; approximately 14,000 years ago, mainland Australia was linked to both New Guinea and Tasmania, the British Isles formed an extension of continental Europe via the dry beds of the English Channel and North Sea, and the dry basin of the South China Sea linked Sumatra, Java and Borneo to the Asian mainland.

http://en.wikipedia.org/wiki/Beringia

Just fascinating that happened so long ago, well really its not that long ago in the scheme of things.

Professor Lennart Bengtsson - the scientist at the heart of the "Climate McCarthyism" row - has hit back at his critics by accusing them of suppressing one of his studies for political reasons.
http://www.breitbart.com/Breitbart-London/2014/05/16/Climate-McCarthyism-the-scandal-grows

A leading climate scientist has resigned from the advisory board of a think-tank after being subjected to what he described as “McCarthy”-style pressure from fellow academics
http://www.thetimes.co.uk/tto/environment/article4090137.ece

The Bengtsson scandal comes at the end of an exceedingly bad week for the cause of climate alarmism. In other news, still further scorn has been poured on the methodology of the Cook et al paper on the "97 per cent consensus."http://wattsupwiththat.com/2014/05/15/university-of-queensland-threatens-lawsuit-over-use-of-cooks-97-consensus-data-for-a-scientific-rebuttal/

The 97% claim is out the door, done, finished. They wont even publish it anymore because they are afraid of the scrutiny. And note it came from the university of Queensland to begin with.   

I felt this thread was appropriate to post this information on. People need to understand the truth. Climate change is NOT MAN MADE.

Chrissy wrote:

The 97% claim is out the door, done, finished.

Climate change is NOT MAN MADE.

I wish I wasn't so dumb. If I had even average intelligence I would be either completely convinced that manmade climate change is real or completely convinced that it's a total fraud.
But without that kind of intelligence it's just too hard to know which side is fulla shit.

This is a simple read. And there are two simple facts to remember that blow agw out of the water. One... petroleum is a finite resource and we are already making progress towards alternatives. Two... there will be another ice age. It's that simple.

http://news.bbc.co.uk/2/hi/science/nature/4081541.stm

How far off is the next ice age?

By Carolyn Fry

With global warming taking centre stage in the climate change debate, the idea that Earth might be heading towards an ice age seems outdated.

Yet scientists studying microfossils from deep-sea cores have discovered that we may still have much to learn about the cycles of ice advance and retreat that have affected Earth for a million years.

Periods of ice advance are known as glacials, while the warm periods are known as interglacials.

In the past, it was thought all interglacial periods lasted for around 11,000 years, in line with Earth's natural orbital cycle around the Sun, but new findings show events on the planet's surface may also influence the timing of ice advances and retreats.

It is important that we understand these natural climatic rhythms as our current interglacial has lasted 11,500 years and could potentially end at any time.

Although the current human-induced high levels of carbon dioxide (CO2) in our atmosphere are thought to be unprecedented in the recent geological record, some scientists argue that it's possible the changes we are making by pumping CO2 into the atmosphere could ultimately help usher in the next ice age.

"There are operations within the climate system that we still don't fully understand," explains Professor Chronis Tzedakis, from Leeds University, UK.

"It's possible that our pumping greenhouse gases into the atmosphere could somehow lubricate the flipping from one state to another."

Core value

Professor Tzedakis and colleagues studied tree pollen and tiny fossilised marine creatures called foraminifera from a sediment core taken close to the Tagus river estuary off the coast of Portugal.

Sea water contains two major isotopes, or types, of oxygen, O16 and O18. The O16 isotope is lighter and evaporates more readily than the heavier type.

When this happens during an ice age, O16 ends up being locked away in ice on land and the remaining seawater becomes enriched with the heavier O18 isotope.

Fluctuations show up in the chemical composition of foraminifera, which means they can be used to deduce the amount of ice volume that was around at the time they were alive.

Meanwhile, preserved pollen discharged into the sea by rivers reflects the extent of forest cover, which is known to increase and decrease with warming and cooling.

Extracting both sets of data from a single core provides scientists with a picture of changes occurring both on land and the sea.

Advance and retreat

In the 1990s, researchers had investigated the interglacial prior to the one we are in now, which began 132,000 years ago. So Professor Tzedakis' team opted to look farther back in time to the interglacials that started 240,000 and 340,000 years ago respectively.

They expected to see a similar pattern to the last interglacial findings, which had revealed the warm period lasted 16,000 years and that there was a 5,000-year time lag between the ice retreating and the appearance of forests, and again between the ice advancing and the trees disappearing.

However, the new findings showed up a completely different cycle of events.

"Much to our surprise we found that pattern was not replicated," said Professor Tzedakis.

"We didn't have a big lag between the onset of the interglacial and establishment of trees plus there wasn't the persistence of forests into the period of ice growth."

Of particular interest was the pollen data from the interglacial beginning 240,000 years ago as this showed the opposite sequence of events.

Here, the forests seem to have disappeared after 6,000 years of warmth, despite there being no detectable change in the amount of ice cover.

The decline mirrored reductions in atmospheric methane observed in ice cores from Antarctica, suggesting it was a global rather than local event that prompted their demise. Following the disappearance of the trees, the ice sheets then gradually advanced.

The scientists believe this shows that different mechanisms operating within Earth's climate system can impinge on the underlying orbital controls of glacial-interglacial cycles.

In the case of the trees disappearing from Portugal before the advance in ice they believe an unknown global event, which may have also caused lower atmospheric methane levels, prompted them to die back.

Global impact

If vast areas of heat-absorbing forests in Siberia were also affected and replaced by tundra, this would have increased the solar energy reflected back into the atmosphere, in turn cooling the planet's surface temperature and encouraging ice growth.

It is this unusual turn of events which has got the scientists thinking that our impact on global climate could yet prompt the return of another ice age, despite the fact that global temperatures are currently increasing.

They now plan to extend their research to look back at one more interglacial, which began 400,000 years ago. This has the best potential to shed light on future climate change as the natural geometry of the Earth's orbit was the same at that time as it is today.

"It's a fascinating period," says Professor Tzedakis. "It appears to have been quite warm and wet and to have lasted a long time; possibly 30,000 years. Within the context of our present study it will be important to see how the forest reacted within the ice-free period."

Although today's unnaturally CO2-rich atmosphere is not replicated in climatic records of the recent past, the information gleaned from cores provides a means for scientists to test the accuracy of models designed to predict future climate changes.

At the Met Office's Hadley Centre for Climate Prediction and Research, scientists are finding that land cover has an important role in influencing climate.

"We're increasingly finding that we have to include the effects of changes in land cover in our models," said carbon cycle research scientist Chris Jones.

"Both [man-made] and natural changes in forest cover have a significant effect on climate, so being able to understand how changes in cover worked in ancient climates is extremely useful."