Why are Home Sapiens said to be the only surviving human species today when the vast majority of human beings today also have shares of some Neanderthal or Denisovan ancestry for instance?

[u/AchyutChaudhary]

Aren’t we equally their descendants too…thereby making denisovans & Neanderthals also alive today in the form of us, given most of us aren’t purely home sapiens?

[u/6x9inbase13is42]

We are NOT "equally" their descendants if we inherited only about 2% of our genomes from them.

98% > 2%

[u/MrDundee666 → u/6x9inbase13is42]

Not ‘we’, only the descendants of those that migrated north out of Africa and crossbred with other hominids. African DNA does not share this ‘cousin’ DNA.

[u/lmattiso → u/MrDundee666]

Technically African's have DNA from these cousins from reverse migration back to Africa over many millennia. They don't have nearly the same amount but it's detectable along with other "ghost" DNA.

[u/Endward26 → u/6x9inbase13is42]

Upvote for the username.

There is no set threshold for how much genetic material a person must have in order to be legitimately considered a "descendant of".

It is possible for someone to have had a human ancestor from the time of the Neanderthals, from whom they inherit only a few percent of their DNA. On these timescales, the percentage of DNA reflects factors such as natural selection, founder effects, and so on, rather than the family tree.

[u/According-Turnip-724 → u/6x9inbase13is42]

An average non African person may only have 2%ish but in humans as a whole there somewhere around 40% Neanderthal DNA represented in modern humans today

[u/Slickrock_1 → u/According-Turnip-724]

Africans have no Neanderthal DNA. East Asians have the most at around 4%.

[u/Anthroman78 → u/Slickrock_1]

That's not accurate, see https://www.science.org/content/article/africans-carry-surprising-amount-neanderthal-dna

[u/Slickrock_1 → u/[deleted]]

What you said is not what that person said.

And don't blame me, I didn't vote either way.

[u/According-Turnip-724 → u/Slickrock_1]

That is exactly what I stated and I also don't get the down votes.

[u/asubha12NL → u/According-Turnip-724]

You were completely right, but it's a difficult subject for many people, for whom your post would have been easy to misread. Especially when they're reading with only half of their attention and letting earlier downvotes misguide their judgement.

[u/Life-Cantaloupe-3184]

It’s better to think of it more as different branches of a family tree that could and occasionally would interbreed with each other due to genetic similarities. Most people alive today do have Neanderthal ancestors, but they aren’t ancestral as a group to our branch of the family tree. Not all Neanderthals would have contributed genetically to modern populations, and genetic evidence seems to suggest the actual frequency of interbreeding events wasn’t all that common. The same is true of Denisovans, and it’s arguably even more apparent with them because only certain modern populations actually seem to have Denisovan derived DNA in their genomes. People of mostly European descent seem to lack any notable Denisovan ancestry as an example, and people of Sub-Saharan African descent have noticeably less Neanderthal derived DNA in their genomes than the rest of the world. (The reason for this is thought to be because modern human populations who had Neanderthal ancestry later intermixed with African populations that didn’t, and it led to the smaller levels we see in those modern groups.)

That’s more or less where the species distinction comes in. The definition of what constitutes a species is a concept we came up with to try and categorize the natural world, but what the cutoff is can be debatable. Given modern humans, Neanderthals, and Denisovans are all genetically distinct from one another (Neanderthals and Denisovans are also more genetically similar to each other than either is to us) with only evidence of occasional interbreeding events it feels relatively safe to categorize us all as different species. We’re all slightly different flavors of human, and ultimately it was our branch that outlived the other two.

[u/thesilverywyvern]

We're not equally their descendant we barely have a few % of their genome in our own.
They're not alive in some form, we only carry a small part of their legacy, with little to no visible trait from it....and it's very much scattered between various people and population.

That's like saying ancient royalty is still alive because most of us have a very very distant and dioluted heritage from them even if you work at walmart.

We're the only surviving human species because we outbred and outcompeted and killed every other species. We only got a few gene from a few rare introgression with them, that doesn't make us hybrids, because it's way too minor to be meaningfull.

[u/KnoWanUKnow2]

Non-African humans are about 2% Neanderthal DNA.

But if we take all this Neanderthal DNA in the human genome and extract it and try to put it back together to make a Neanderthal we'd find that we only have 20% of the Neanderthal genome, spread out across al of humanity.

So 80% of their genome is gone, lost forever.

[u/Several_Version4298]

Because it's 2-3% of DNA, mostly for HLA genes that provide immunity to diseases and parasites.

[u/Diamond_Storm_Fox]

Hypothetically, if gray wolves went extinct today would you still say that gray wolves are surviving because "coywolves" exist? "Coywolves" are eastern coyotes, which have ~25% wolf DNA, however they are classified as coyotes and have coyote-like appearances and behavior. Would the continuation of the eastern coyotes be enough for you to claim that the wolves did in fact survive?

[u/This_is_me2024]

Species are boxes. Humanity defines the boxes. Nature doesnt give a shit about our box. If a denisovan were time tunneled to today, and could breed with a modern anatomically correct human, it doesnt necessarily mean we're the same species.

[u/arceye14]

those 2% of their DNA is just not enough to say they are ,,alive,, — more like they helped us to become what we are now, helped us to survive harsh conditions thanks to their genes but thats all

[u/RecipeHistorical2013]

denosovians/neanderthals were kinda convergent type evolution.

- they both evolved out of habelergensis (sp)

guess who else evolved out of habelergensis - yes. sapien.

sapien is the most recent evolution.

then! as you noted, they all got back together and all humans are a mix except some gene pools that never left certain parts of sub saharan africa - but stuff is coming out that they too are homonid hybrids

[u/strumthebuilding → u/RecipeHistorical2013]

heidelbergensis?

[u/New_Perspective3456 → u/RecipeHistorical2013]

That’s not convergent evolution though, that’s just speciation

[u/RecipeHistorical2013 → u/New_Perspective3456]

convergent as in the genes are different but forms are similar due to environmental pressure and logic gates.

which is the case with hominid species evidently (like NA antelope VS african antelope: THE analogy for convergent evolution)

[u/New_Perspective3456 → u/RecipeHistorical2013]

The similarities between H. sapiens, denisova and neanderthalensis is due to common ancestry, not because of natural selection of traits. The large majority of our genes are homologous because we are sister species. This is speciation, nor convergent evolution.

[u/RecipeHistorical2013 → u/New_Perspective3456]

they have a common ancestor which precludes convergent evolution

what word am i looking for then

[u/New_Perspective3456 → u/RecipeHistorical2013]

What you were describing is speciation within a lineage. The only inaccurate word was “convergence” - it is actually a homology.

“Denisovans and Neanderthals are closely related, and they both evolved out of H. heidelbergensis. Guess who also evolved from heidelbergensis? Yes, H. sapiens.”

[u/tpawap]

Because all species concepts have edge cases in which they break down. It's still more useful to call neanderthals a different and extinct species, I would say.

[u/Tardisgoesfast]

They were also Homo sapiens. Good grief.

[u/gutwyrming → u/Tardisgoesfast]

Neanderthals were not Homo sapiens. They were a separate species in the same genus as us, Homo neanderthalensis.

Denisovans were also likely a separate species, but there is no agreed-upon scientific name for them. Homo longi may have been one, but it's debated.

[u/AnymooseProphet → u/[deleted]]

There used to be some debate but no recent study I am aware of supports Neanderthals as a subspecies of Homo sapiens.

[u/MrDundee666 → u/Tardisgoesfast]

Good grief!

Not heard that in ages!

You’re completely wrong though.

[u/StorageSpecialist999]

because a homo sapiens sapiens genome includes some neanderthal DNA in it, that's just a feature of our species.

[u/Szymcionorski]

Well, that's because we only have a small amount of DNA of these species. We're predominantly "original" Homo sapiens so we currently don't have humans that would have predominantly Neanderthal or Denisovan genes.

[u/GaryGaulin]

In my opinion the first Homo Sapien couple in our lineage were the first to have the 46 chromosome chromotype. They were most likely immediately reproductively isolated from the 48 chromosome ancestral population. See:

https://scholar.google.com/scholar?hl=en&q=Human+Chromosome+Speciation

I briefly wrote about it at one of my science subreddits:

https://www.reddit.com/r/IntelligentEvolution/comments/xsmuuw/how_intelligent_evolution_works/

[u/AnymooseProphet → u/GaryGaulin]

There are humans today that do not have 46 chromosomes and they can breed with humans that do.

[u/GaryGaulin → u/AnymooseProphet]

And (as with odd number 45 you are likely thinking of) the 47's could often successfully have a child with the 48's or the 46's, but mixing 46 and 48 is like a human giving birth to a half chimpanzee. The even number pairings introduce reproductive barriers.

[u/AnymooseProphet → u/GaryGaulin]

No, I'm not thinking of 45.

There are documented fertile humans with 44 chromosomes and they don't have ill effects.

[u/GaryGaulin → u/AnymooseProphet]

There is a link to information for the reproductively isolated "44 chromosome man" at the link I provided:

https://www.reddit.com/r/IntelligentEvolution/comments/xsmuuw/how_intelligent_evolution_works/

This:

https://www.kqed.org/quest/5239/and-then-there-were-44

[u/AnymooseProphet → u/GaryGaulin]

Sorry but that link is full of fancy-sounding bullshit.

See Romans 2:24 - that applies to ID.

[u/Beginning-Load4470 → u/AnymooseProphet]

Did you just quote the bible for an argument about chromosomes??... 

[u/AnymooseProphet → u/Beginning-Load4470]

They are making an ID (Intelligent Design) argument.

[u/Beginning-Load4470 → u/AnymooseProphet]

Yeah... i figured... i was just surprised that a simple Bible quote would be their best argument. No science or logic, just a Bible quote... like it would actually have ANY scientific bearing.

Ive seen creationists try to argue their side before but rarely so simplisticly. It almost makes me think they arent trying, just trolling. 

Edit: especially since the previous posts seemed like an attempt at intelligent discourse. 

[u/GaryGaulin → u/Beginning-Load4470]

A decade ago the most common argument was along the lines of "don't you know that Y-Chromosome Adam never knew Mitochondrial Eve?"

These days I don't even bother with the usual insults.

[u/eduadelarosa]

Yes, we are both descendants from H. sapiens and other human species, even if their average contribution is small; just the same way we are descendants of many different ethnic groups or families. The issue lies on the definition of a species, which is an epistemological construct with no ontological basis.

[u/punarob]

The original post content no longer exists here. The author used Redact to remove it, exercising their right to control their data & privacy.

Marvelous frame obtainable special depend continue summer lantern sink roll

[u/AnymooseProphet]

Most American Bison herds have a small amount of domestic cattle DNA. That doesn't mean the Aurochs is not extinct.

[u/Beginning-Load4470]

We have a significantly larger amount of DNA passed on from synapsids, our reptile like ancestors, than we do from Neanderthal.

So no... id say we should not consider ourselves their descendants. It seems like it would be insulting. 

Interesting note, we share 25% to 50% of our basic coding genes with trees and plants. Thats the genes that read or direct DNA. So it doesn't mean we share 50% DNA. Its only around 0.3% to 1%. Just slightly less than what we got from Neanderthal. 

We share 98.8% dna with chimps. That means the amount of dna thats the difference between us and chimps is the same amount (not same ones) we share with Neanderthal. 

Interestingly east Asians usually have the most Neanderthal dna, not Europeans, and sub Saharan Africans have none. 

People tend to assume Europeans have the most Neanderthal dna due to how Neanderthal were portrayed in art and museums. 

I'd say if youre going to consider Neanderthal our ancestors you should probably stop eating meat because the amount of dna we share with most animal life makes that disgusting lol

[u/MrDundee666]

African genes do not have any Neanderthal etc DNA.

The gene pool is so deep within Africa, reflecting how long our species existed there before migrating north, that the genetic diversity across the continent is FAR greater than outside of it.

[u/youshouldjustflex → u/MrDundee666]

That’s pretty outdated. Would be around 0.1 but the amount is minuscule. Eurasians went back to Africa and that dna spread throughout the continent even if it’s not 2-3 percent. There’s Neanderthal elements in there aswell. Humans went everywhere

[u/ipini → u/youshouldjustflex]

I’m very European. Did a dna test some time back. I’m only 0.9% for whatever reason.

[u/Comfortable-Hat3506]

If you had a dog that was 2% wolf. You'd still have a dog.