
Humans Interbred with Four Extinct Hominin Species, Research Finds - ryan_j_naughton
http://www.sci-news.com/othersciences/anthropology/humans-hominin-introgression-07438.html
======
hashberry
"Homo sapiens" is Latin for "wise man," but there were many Hominin species
who possessed comparative culture, art, and intelligence. Neanderthals
actually had larger brains compared to modern humans[0]. There are many
theories on why Neanderthals became extinct[1]; my favorite is that we simply
outbred them because of our sex appeal. What is Latin for "sexy human?"

[0]
[https://en.wikipedia.org/wiki/Neanderthal#Anatomy](https://en.wikipedia.org/wiki/Neanderthal#Anatomy)

[1]
[https://en.wikipedia.org/wiki/Neanderthal_extinction](https://en.wikipedia.org/wiki/Neanderthal_extinction)

~~~
orange8
They had greater cranial capacity than us, but so do elephants and whales. And
the animal with the greatest brain-to-body-size ratio is tree shrew,
suggesting that size doesn't really matter when it comes to intelligence.

~~~
1000units
Neither of those animals has the appropriate morphology to build tools or use
complex language. How do we know they aren't actually smarter than us?

~~~
Juliate
> or use complex language.

That we know of. They might completely have complex language using different
mediums (infra sounds, vibrations, movements, smells, etc.).

~~~
orange8
I believe all animals definitely have some sort of language, and that the
complexity of a language depends on its utility in facilitating everyday
interactions and activities. What are the most complex activities you've seen
elephants get up to?

~~~
Juliate
I never had the chance to meet elephants.

Now, from what I've learned/read about their behaviours, I have no doubt on
the depth of their lives.
[https://en.wikipedia.org/wiki/Elephant_cognition#Elephant_so...](https://en.wikipedia.org/wiki/Elephant_cognition#Elephant_society)

And I wouldn't call that "some sort of language". That's language. Species-
specific. Not "human" language.

Even language that another species can grasp more or less perfectly. You can
get that with minimal observation of dogs, cats, even birds. And obviously,
animals read us as well.

Now, the complexity of an other species language may be partially out of reach
because we do not have the same senses, abilities, history, memories.

So they might even engage in activities we cannot grasp or identify (and
reciprocally) but for great patience, observation, study, understanding, and
luck.

~~~
renlo
When I see a videos / images of wolves I don’t perceive that “intelligence”
that I perceive from dogs. Not to say wolves are any less intelligent or
cognitive, dogs just have had the constraint that they needed to be able to
communicate with humans well or they could die.

Kind of makes me think if we ever were to encounter extraterrestrial
intelligence we might have trouble identifying them as intelligent, or, have
trouble communicating with them, because we have trouble identifying and
communicating with the terrestrial intelligence that surrounds us and is
abundant.

~~~
simondw
Depends on the situation in which we encounter the aliens. If wolves were
building interplanetary spacecraft, we'd have a hard time saying they weren't
intelligent.

~~~
Juliate
If they were, we probably wouldn't be there to see it. :D

Where No Wolf Has Gone Before.

------
c3534l
If we interbred with them, how are they actually species? It seems more to me
you're talking more about racial or breed differences akin to breeds of dogs
if two species actually successfuly had viable offspring in the wild.

~~~
joe_the_user
Yeah, seems more logical to say ancient human experienced a number genetic
divergences which were then folded into the mainline of the genetic stream.

~~~
0x8BADF00D
Environment plays a huge role. If a nomadic group was in a jungle-like
environment, wouldn’t they more likely develop the traits of the other species
well suited for jungle living? Over a long enough timescale.

~~~
thaumasiotes
> If a nomadic group was in a jungle-like environment, wouldn’t they more
> likely develop the traits of the other species well suited for jungle
> living?

Yes, and this has already happened. The African jungle has its pygmies; the
Southeast Asian peninsula and surrounding islands have their pygmies; and
those two groups are totally unrelated.

------
sadness2
What is the difference between the genes identifies as "extra-species sourced"
and those which are a nominal part of homo sapiens DNA? How do we know they
don't originate from intra-species mutation, for example?

~~~
ajross
Genes tend to to accumulate mutations at a constant rate (lots of caveats
here, but that's the general idea). If you find that a population has a family
of gene variants that are very different from the same ones in another
population, then it's a good bet it arrived from external breeding. And the
relative differences between the modern descendant genes can tell you when it
happened.

Again, I'm sure the real models get really complicated and are no doubt still
a little controversial. But that's the basic idea.

~~~
flukus
How do they differentiate multiple parallel lines lines of mutations coming
back together from a separate subspecies existing for much longer?

~~~
ajross
Genes don't "come back together". If you have a given gene, it's a direct
descendant from exactly one of your ancestors in each generation.

------
snackematician
I would be very cautious interpreting these results. There are no DNA samples
from the putative EH1 and EH2 hominin populations -- these populations are
statistical constructs used to explain the data, but not (yet) directly
observed.

I do think it's likely that H. sapiens intermixed with other hominins besides
Neanderthal and Denisovan, but the models used to infer these results make a
lot of assumptions and are at best a drastic simplification of reality.

~~~
keiru
Goes to show that every field has its own inferred "dark matter" of sorts.

------
oflannabhra
If you are even vaguely interested in ancient human DNA, human migration, or
human evolution I highly recommend Insito.me's[0] podcast, The Insight [1].
Improvements in genomics DNA extraction techniques combined with several key
paleontological finds, have resulted in a revolution in human paleontology and
anthropology.

[0] - [http://insito.me](http://insito.me)

[1] - [https://podcasts.apple.com/us/podcast/the-
insight/id13247444...](https://podcasts.apple.com/us/podcast/the-
insight/id1324744423?mt=2)

------
mirimir
> “For example, all present-day populations show about 2% of Neanderthal
> ancestry which means that Neanderthal mixing with the ancestors of modern
> humans occurred soon after they left Africa, probably around 50,000 to
> 55,000 years ago somewhere in the Middle East.”

I gotta wonder what people are thinking when they write this stuff. I mean,
"Neanderthal mixing with the ancestors of modern humans occurred soon after
they left Africa". Do they imply that those whose ancestors never left Africa
are not "modern humans"? I doubt it. So they're just being sloppy.

------
firecall
I'm curious; can we assume they were similar enough to be attractive or
desirable as mates?

It's obvious different cultural standards may have applied.

Or am I asking a stupid question?

~~~
booleandilemma
Humans nowadays are attracted to everything from anime characters to people
dressed in furry animal costumes. The set of things we’re attracted to knows
no bounds.

~~~
keiru
Perhaps the real evolutionary advantage of Sapiens was abstract thinking put
to use in advanced sexualization of different species.

------
grinsekatze
[https://web.archive.org/web/20190730011623/https://www.sci-n...](https://web.archive.org/web/20190730011623/https://www.sci-
news.com/othersciences/anthropology/humans-hominin-introgression-07438.html)

------
bratbag
Given that we carry the genetic legacy of all these Hominin species, are we
still homo-sapiens?

Should modern humans be classified as something else, distinct from the
original pre-interbreeding homo-sapiens?

If so, given how randy we have been, I propose Homo-Amatorius.

~~~
gervu
The two named species from the research are _Homo_ _sapiens_ _denisova_ and
_Homo_ _sapiens_ _neanderthalensis_. We're _Homo_ _sapiens_ _sapiens_ ,
because we ate the wise-wise fruit.

(The other two are nameless data ghosts at this point, due to lack of
corresponding archeological records, but presumably _Homo_ _sapiens_
_whateveris_ and _Homo_ _sapiens_ _someotheris_.)

It's kind of open to debate whether those should be independent species, or
their own species, but basically we're all _Homo_ _sapiens_ of one sort or
another unless you want to get into a long unresolvable highly technical
argument about it, which revolves around what precise definition of "species"
is useful in some arbitrary context.

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BasDirks
Can these species be said to be extinct when their DNA is very much alive?

~~~
ben-schaaf
Birds evolved from dinosaurs, certainly those are extinct, yet they share a
large portion of DNA.

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40acres
This theory was one of the most interesting ideas in _Sapiens_ , take a look
at a model of what other great apes look like, if so many types of dog can
interbreed why wouldn't these great apes?

~~~
solipsism
This is misleading. Superficial physical appearance isn't always a good
indicator of genetic similarity or sexual compatibility.

~~~
ajross
Who's downvoting this? This is exactly correct. In fact domestic dogs have
IIRC considerably less genetic diversity than their wolf ancestors do.

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WalterSear
Then they aren't extinct.

~~~
BurningFrog
2.3% Neanderthal Pride checking in!

~~~
dang
Please don't post flamebait to HN.

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

------
Jeff_Brown
*homonym

------
anentropic
typical

------
corodra
Hi everyone, just letting you all know, it's no surprise that modern homo
sapiens ancestors bumped uglies with other species in the genus of homo back
in the day. The enlightening part of this article is there are some unknown
species in homo that we have genetic evidence of, but no fossil record. The
thing you should be fascinated by, there were many contemporary relatives to
homo sapiens that could have been as much or somewhat as intelligent. But they
all disappeared and we are all that's left. We either killed them all or snoo-
snooed them out of existence because homo sapiens seemed to have spawned
faster and had more offspring in comparison.

So, please stop relating this to dogs fucking or being surprised that
different species can tango under moonlight. Please stop.

Yes, different species, of different genders, of the same genus can warm up at
night and spawn little hellions 7-9ish months later.

There's plenty of evidence that these other homo species were sophisticated,
like the neanderthal. As much, if not more, that ancient homo sapiens (at the
time).

Does that make a new species? Maybe. Current taxonomy guidelines are not
perfect. There are other taxonomy systems out there that would spell this out,
just not considered the universal standard we all know today. The problem is,
how do you draw sharp lines in a blurry distinction without just creating a
new "species" for every sexual adventurous encounter that results in a
screaming child.

At the end, this article was cool and we should all be excited over this.

~~~
JoeAltmaier
Yes that's the interesting part. But disagree that 'there's plenty of
evidence'. The fact is, there's no evidence whatsoever - that's what 'unknown
species' means.

------
peter_retief
So its possible that modern races of humans are actually our archaic
ancestors?

~~~
runarberg
No, what most people refer to as races of humans are a set of traits that are
surprisingly shared across populations, albeit in different quantities.

The traits that we’ve inherited from our archaic ancestors aren’t really the
types of traits people use a distinguishing features between populations.

~~~
peter_retief
Question is would the Neanderthals have also shared traits with other
hominids? I find that religion and politics kind of muddies the science with
human evolution

~~~
runarberg
I am not an expert. But it seems less likely since the Neanderthals existed
for a shorter timespan over shorter distances then modern humans, so they must
have encountered fewer hominin along their way.

If anything it is more likely that the deninsovans aquired genes from the
decedents of the groups of Homo Erectus that migrated throughout south east
asia and quite probably remained in small quantities in remote areas (like
Homo Floresiensis did) when the denisovans arrived.

\---

Edit: Then it is the question of: Say that the Denisovans acquired genes from
other hominin through interbreeding, would these genes then be passed on to us
when our homo sapien ancestors interbreed with the Denisovans? That is a
question I have no confidence in answering and should probably be deferred to
geneticist or a genetic statistician.

------
tropo
Suppose we found enough DNA to recreate these hominins.

Would they be citizens or zoo animals? Either way, what if they want to
interbreed? Do we determine this based on looks? What if the attraction is
unidirectional?

~~~
inciampati
They would be citizens. They would grow up like normal children. They would
speak any human language. They could achieve anything any other human could in
their lives. The differences would be subtle. They would appear like unusual
humans to us, a racial group that we had never encountered. We would certainly
see more commonalities with other modern humans than differences. All their
traits would be present to some extent among living modern humans, but they
would show us a unique and intense combination of those traits.

~~~
danieltillett
This is a massive assumption that we don't know is true.

------
excalibur
[https://en.wikipedia.org/wiki/Identical_ancestors_point](https://en.wikipedia.org/wiki/Identical_ancestors_point)

> In 2004, Rohde, Olson and Chang showed through simulations that the
> Identical Ancestors Point for all humans is surprisingly recent, on the
> order of 5,000-15,000 years ago.

How can different populations of modern humans have interbred with different
hominin species around 50k years ago when ALL of today's humans had the EXACT
SAME SET OF ANCESTORS as recently as 15k years ago?

~~~
dragonwriter
> How can different populations of modern humans have interbred with different
> hominin species around 50k years ago when ALL of today's humans had the
> EXACT SAME SET OF ANCESTORS as recently as 15k years ago?

Differences in past populations, including the interbreeding at issue, can be
inferred from modern genes for reasons actually laid out in your own link, in
the paragraph after the one you quoted:

 _All living people share exactly the same set of ancestors from this point
back, all the way to the very first single-celled organism. However, people
will vary widely in how much ancestry and genes they inherit from each
ancestor, which will cause them to have very different genotypes and
phenotypes._

~~~
excalibur
This actually makes sense, thank you for actually reading the Wikipedia page
rather than just searching for a quote :)

It doesn't really contradict this article, but there were a number of articles
a couple of years ago about how Europeans had Neanderthal DNA that other
ethnicities didn't share. In reality all modern humans are descended from the
exact same Neanderthals, but Europeans still retain more of their genes.

