With the ability to sequence ancient DNA, we now know that some modern humans got busy
with each other, Neanderthals, and at least two other ancient human groups.
Which begs the question: who wouldn’t our ancestors get freaky with?
Hey guys!
Anatomically Modern Human Natalia here for DNews!
When our ancestors left Africa and trekked into Europe, the Middle East, and Asia, they
crossed paths with other ancient human groups like Neanderthals, Denisovans and at least
one other group.
Apparently, humans weren’t so picky about their sexual partners, so they admixed - “science”
for got down with - these other archaic humans.
How do we know?
It’s all in the genes!
Scientists have been able to find the DNA of these other archaic humans in living populations
today.
This love story has four characters.
First -- Neandertals.
These hearty hominins lived in Europe, the Middle East and Western Asia roughly 400,000
to 40,000 years ago.
Because they had lived in the harsh cold of Eurasia far before modern humans left Africa
their biology was adapted to that climate.
They had thicker and lighter skin, which helped with vitamin D absorption, a bigger nose designed
to warm cold air, and a stockier build to retain heat.
Tres sexy, no?
Second character in this love story?
-- well in 2008, a new archaic human lineage was discovered in the Denisova Cave in Siberia.
Scientists found a finger bone with viable DNA and were able sequence the genome.
It turns out it belonged to a young adult female who lived roughly 40,000 years ago
and these new archaic humans were dubbed the Denisovans!
Researchers have been able to find traces of Denisovan DNA in populations as far as
Southeast Asia stretching to Australia.
This indicates that Denisovans and their descendents may have had a greater geographic area than
previously thought.
Now, I know there's a third "mystery" guest, but we'll come back to them.
So, in 2003 we sequenced the human genome, in 2010 we sequenced the Neanderthal and the
Denisovan genome about the same time.
Now that we've done all that, we can compare all this DNA.
And the results were shockingly sexy.
Scientists found Neanderthal DNA, Denisovan DNA, and that mystery group’s DNA in current
living populations!
This is how we know that many people of Eurasian descent have a small percentage of Neanderthal
DNA in their genome like our very own Trace.
Natalia, do these “genes” make me look Neanderthal?
Hm, give or take Trace percent.
Alriiiight
But what were the potential benefits of admixing with Neanderthals and Denisovans -- besides
producing Trace, of course?
When humans mated with these other ancient groups scientists argue that they picked up
genes that improved their immune system and helped them adapt to a new environment.
Researchers found that those of European and Asian ancestry had a higher abundance of human
leukocyte antigen genes, or HLAs.
HLA is a protein that helps regulate our immune system.
This is an example of hybrid vigor, or the tendency of a crossbred individual to show
qualities superior to those of both parents.
And remember that fourth mystery group we've danced around?
Well, scientists have found a 3rd population of archaic humans that we got *ahem* friendly
with as we migrated into Asia and down into Australasia.
This 'Unknown DNA' has been found in populations of South Asians, Southeast Asians, and Australasians
- including the population of the Andaman Islands.
Roughly 2-3% of of this unknown DNA has been found in individuals in the region.
Researchers think that this new possible ancestor could help explain the shorter stature of
people in those areas!
These new data also support that there was only one main wave of migration out of Africa
into Asia rather than two waves as is also hypothesized!
DNA is truly fascinating-- not only is it the building blocks of an organism, it can
tell the story of a species’ journey through time and space.
And who they boned.
Admixing with Neanderthals may have been good for our health, but research shows they were
far smarter and artistic than previously given credit for.
Check it out!
What about you?
Would you get down with a Neanderthal?
A Denisovan?
An unknown human ancestor?
C’mon...be honest.
Let us know in the comments below and don’t forget to like and subscribe for more DNews
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