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'Ghost' human ancestor discovered in West Africa – BBC News

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A mysterious “ghost population” of now-extinct ancient human-like creatures may have interbred with early humans living in West Africa, scientists say.

Researchers suggest DNA from this group makes up between 2% and 19% of modern West Africans’ genetic ancestry.

They believe the interbreeding occurred about 43,000 years ago.

Scientists found links to the Mende people of Sierra Leone, Yoruba as well as Esan people in Nigeria, plus other groups in western areas of The Gambia.

The new study was published in Science Advances this week.

It suggests that ancestors of modern West Africans interbred with a yet-undiscovered species of archaic human, similar to how ancient Europeans mated with Neanderthals, and Oceanic populations with Denisovans.

The research sheds more light on how archaic hominins added to the genetic variation of present-day Africans, which has been poorly understood even though it is the most genetically diverse continent.

Hundreds of thousands of years ago there were several different groups of humans including modern humans, Neanderthals and Denisovans.

The newly-discovered “ghost population” of ancient human species seems likely to have diverged from these groups.

Sriram Sankararaman – the computational biologist who led the research at the University of California in Los Angeles – told BBC Newsday he believed more such groups would be found in the future.

His team looked at the genetic make-up of West Africans and found that some of their DNA came from an ancient unexplained source.

“As we get more data from diverse populations – and better quality data – our ability to sift through that data and excavate these ghost populations is going to get better,” Mr Sankararaman said.

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Here's NASA's new idea to get its stubborn Martian drill to work – Mashable

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The InSight lander’s robotic arm.
Image: nasa jpl

Well over a year after NASA’s InSight lander parachuted down to the Martian surface, the space agency still hasn’t been able to drill too far into the red soil. 

NASA has tried a few different techniques to get the drill, known as the “mole,” deeper into the ground to measure the desert planet’s inner temperature —  with the greater goal of understanding geologic activity on Mars. 

On Friday, NASA announced a new idea. From tens of millions of miles away, the space agency will direct the InSight lander to take its robotic arm (which has a black shovel on the end), to “push” on top of the drill. 

“The InSight team hopes that pushing on this location will help the mole it bury itself and enable the heat probe to take Mars’ temperature,” NASA said.  

Eventually, NASA hopes the mole will drill down 16 feet. So far, however, the agency hasn’t gone much more than a foot.

The new extraterrestrial operation is expected to take a few weeks, if it works at all. 

“We’re cautiously optimistic that one day we’ll get the mole working again,” Ashitey Trebi-Ollennu, the lead InSight arm engineer at NASA’s Jet Propulsion Laboratory, said five months ago, when attempting another drilling scheme.  

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U of A scientist lands spot on NASA Mars 2020 rover mission

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Local scientist Chris Herd is part of NASA’s Mars 2020 mission, the first attempt to collect samples from the red planet for a possible return to Earth.

He will be lending his expertise in the analysis of rocks and meteorites and select samples that may provide information about the geological history of Mars.

“Mars 2020 will let us choose where to collect samples and will allow us to get context for the rocks that are collected — their location, surrounding features, and more,” said Herd in a news release Thursday.

His role in the mission is making operational and scientific decisions for the mission’s rover to collect and store samples from the surface of Mars.

“Returning samples with that context is the holy grail of Mars exploration. That’s the reason why it’s so important to collect these with an eye to bringing them back,” said Herd.

The objective of the mission is learning about the climate, geology and signs of past microbial life. He was chosen by NASA as one of 10 experts to help to ensure the samples collected will be as useful as possible. He’s also the only Canadian on the team.

“This is a dream come true for me. I will be helping select which rocks might someday be analyzed in labs on Earth,” said Herd.

The launch window for the mission is July 17-Aug. 5, 2020, landing on Mars on Feb. 18, 2021, a mission that will take 687 Earth days.

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U of A scientist lands spot on NASA Mars 2020 rover mission – Calgary Herald

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In this illustration, NASA’s Mars 2020 rover uses its drill to core a rock sample on Mars.


supplied / NASA

Local scientist Chris Herd is part of NASA’s Mars 2020 mission, the first attempt to collect samples from the red planet for a possible return to Earth.

He will be lending his expertise in the analysis of rocks and meteorites and select samples that may provide information about the geological history of Mars.

“Mars 2020 will let us choose where to collect samples and will allow us to get context for the rocks that are collected — their location, surrounding features, and more,” said Herd in a news release Thursday.

His role in the mission is making operational and scientific decisions for the mission’s rover to collect and store samples from the surface of Mars.

“Returning samples with that context is the holy grail of Mars exploration. That’s the reason why it’s so important to collect these with an eye to bringing them back,” said Herd.

The objective of the mission is learning about the climate, geology and signs of past microbial life. He was chosen by NASA as one of 10 experts to help to ensure the samples collected will be as useful as possible. He’s also the only Canadian on the team.

“This is a dream come true for me. I will be helping select which rocks might someday be analyzed in labs on Earth,” said Herd.

The launch window for the mission is July 17-Aug. 5, 2020, landing on Mars on Feb. 18, 2021, a mission that will take 687 Earth days.

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