Modern humans were in Southeast Asia 20,000 years earlier than thought, ancient teeth reveal

When Dutch archaeologist D. A. Hooijer first saw a pair of weathered teeth recovered from a remote cave on the Indonesian island of Sumatra, he noted that they were about the right size and shape to belong to modern humans. But in 1948, he couldn’t be sure of their identity or their age. Now, harnessing cutting-edge science, a group of researchers has confirmed what Hooijer had suspected: Modern humans lived in Southeast Asia as far back as 73,000 years ago—about 20,000 years earlier than previously thought. The earlier timeline helps fill in the blanks on the migration routes of our early ancestors and bolsters an emerging theory that humans may have dwelled in rainforests much sooner than researchers had assumed.

Previous studies suggested that after evolving in Africa, modern humans eventually made their way to Southeast Asia, but researchers have argued whether they arrived about 50,000 years ago or earlier. Recent studies put modern humans in Australia by about 65,000 years ago, but there has been little direct evidence of an early presence in Southeast Asia.

To unravel the mystery, researchers led by geochronologist Kira Westaway of Macquarie University in Sydney, Australia, decided in 2008 to give the Sumatran teeth another look. She and her team used new techniques, including micro–computed tomography scanning to precisely measure the thickness of the enamel, and luminescence dating to determine when minerals in the rock surrounding the teeth were last exposed to sunlight. They found thick enamel, confirming that the teeth are from modern humans, and pegged the date to between 63,000 and 73,000 years ago, they report today in Nature.

The findings offer new hints about how our early ancestors spread across the world, paleoanthropologist Russell Ciochon of the University of Iowa in Iowa City wrote in an email. “[The teeth] show greater affinity to east Asian humans than later southeast Asian specimens, which may give us some clues about the early dispersal routes of modern humans.” he wrote. The researchers, he says, “have definitively and superbly demonstrated the presence of modern humans in Southeast Asia 20,000 years earlier than previous estimates.”

Though just a pair of teeth may seem like insubstantial evidence, the new analysis is convincing, says paleontologist Patrick Roberts of the Max Planck Institute for the Science of Human History in Jena, Germany. “If they show they are clearly human, which I think they do, then it is enough to document humans in this part of the world.”

And the earlier timestamp also means early modern humans may have overlapped with the hobbit (Homo Floresiensis), a tiny early human species that lived more than 60,000 years ago on another Indonesian island called Flores. Yet it’s unlikely the two crossed paths, Westaway says, because strong currents would have made travel to Flores difficult.

The new findings also suggest that these early colonizers may have been the first to live in a rainforest setting. That’s significant, because researchers have long thought that early humans would have found rainforests unappealing: Why hunt clever monkeys in the treetops when easy-to-catch shellfish and other resources await on the coast?

But Roberts of isn’t fully convinced that these early human colonists did live in rainforests. Fossils from rainforest animals were found at the site but don’t bear the marks of a human kill and may not have coexisted with modern humans.

Still, the study shows that “tropical terrestrial habitats were crucial resources for humans expanding beyond Africa, and our species was flexible enough to adapt to them,” Roberts wrote in an email. “Perhaps it is this environmental plasticity that characterizes our species and has left it the last remaining hominin in the world.”

[Source”timesofindia”]

Upgrade your large kitchen appliances for less than $2,500

Take a look at your kitchen appliances. Maybe you inherited them from the last person who lived in your house or apartment. Maybe they’re mismatched or decades old, or not even working. It’s time to treat yourself to some upgrades.

Even if you’re on a tight budget, you can find a suite of large appliances for less than $2,500 that will keep your kitchen running without emptying your savings account. Be prepared to sacrifice, though — certain features are unavailable on appliances in this price range. For example, French doors and bottom-freezer fridges, slide-in stoves and induction cooktops, and dishwashers with adjustable racks are all products that could set you back $1,000 each.

Here are refrigerators, ovens and dishwashers that work well and will keep your upgrade total less than $2,500.

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Refrigerators

You’ll save some money if you opt for a fridge that has the freezer on top rather than a side-by-side or French-door model.

The GE GTE18GMHES comes in a fingerprint-resistant slate finish.

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GE GTE18GMHES, $585

This is a basic fridge that looks good, thanks to a fingerprint-resistant slate finish. It’s also reliable when it comes to keeping your food cold. And you can find this refrigerator for as low as $585, which makes it even more appealing for your kitchen upgrade.

The LG LTCS24223S has a lot of storage space for a budget-friendly price.

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LG LTCS24223S, $895

This refrigerator has plenty of room for your favorite foods: With 24 cubic feet of total storage space, the LG LTCS24223S is as big as top freezers get, with even more room for groceries than some French-door models.

Stoves

Freestanding stoves with the control panel on the back of the unit are the best value. You can put these models anywhere in your kitchen, which is great if you’re not planning a big renovation soon.

The Samsung NE59J630SB electric range includes a healthy selection of useful cooking modes.

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Samsung NE59J630SB, $700

This electric range with a smooth cooktop has plenty of useful cooking modes and fast performance times, which makes this appliance a good value.

The GE JGB700SEJSS gas range does a fine job of cooking food and it does it consistently.

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GE JGB700SEJSS, $700

This gas range is consistent when it comes to cooking food well, whether you’re baking or broiling, or just boiling water. It’s also easy to use

 

[Source”GSmerena”]