Humans began to rapidly accumulate technological knowledge 600k years ago

Is it?

This is literally the first time Ive seen the word human applied to other hominids. I see many discussions about neanderthals and denisovians and so on. I have never seen them referred to as human.

I think it’s not uncommon to refer to Neanderthals as early humans, I’m sure I’ve read that in many places.

Natural history museum, for example, refers to them as early humans: https://www.nhm.ac.uk/discover/who-were-the-neanderthals.htm...

I'm not sure where you are reading but both layman and scientists commonly use the word "human" to refer to the genus "homo". To look at just one example, Ian Tattersall called one of his books "Extinct Humans" and it is a look at the history of the genus homo:

https://www.amazon.com/Extinct-Humans-Ian-Tattersall/dp/0813...

It is also reasonable to argue that they and we are subspecies of the same species not rather than separate species.

I can't speak to what you have or haven't seen before, but yes it's quite common as informal language among anthropologists with particular kinds of views. Sometimes people will use "modern humans" or "archaic humans" or some other variation to differentiate, but not always and it's usually pretty clear from context regardless.

This is just one of many examples of definitions being extremely unstandardized in human evolution. You get used to it after awhile.

> I have never seen them referred to as human.

I have never seen anything else. But then in French, they are called Neandertal men and Denisova men. So pretty clearly humans.

Of course we are not separate species since successful interbreeding did happen (when the populations interacted).

I think it's typical in non-technical English to use "humans" to refer to homo sapiens only, unless you qualify it, like "archaic/early humans". Without additional context I wouldn't assume somebody talking about humans meant to include e.g. Neanderthals.

Wait a minute. I am part Neanderthal.

Does this mean I am only part human?

I'll admit this is the first I've encountered the concept that "neanderthals and denisovians and so on" are not human. Maybe not biologically modern humans, but I'd certainly consider them fundamentally human.

We're all part of the genus "homo", but to me, "human" refers to "homo sapiens". I was sufficiently surprised to hear that humans were around 600k years ago that I came here to comment.

The Wikipedia article [1] on humans makes the same point. It does acknowledge that some use the term human to refer to all members of the genus homo, but this is not the common usage.

[1] https://en.m.wikipedia.org/wiki/Human

You're also part bacterium and part treeshrew, so I couldn't really say for sure.

Donkeys and horses are not the same species, but they interbreed. Their offspring are called mules. Although mules rarely have offspring, so perhaps not a great example.

Uh, I guess you aren’t reading the same things I am. Neanderthals were definitely “human”.

Qualifications like, “600k years ago”? That’s pretty clearly talking about the humans of 600k years ago. “Early humans” are still humans.

I have never heard anyone refer to Neanderthal as a human unless they are talking in a "those are cavemen, early humans" way that's wrong. Where is this coming from? Is it a non-English world thing?

Generally Neanderthals are pointed out as an exception to cross species fertility since... humans have some Neanderthal DNA.

Wherever it’s coming from, it’s not based on any particular language. Museums in English-speaking countries use the term.

There is supposedly neanderthal DNA in some modern humans, implying that offspring were viable. Breeding resulting in viable offspring is one of the only consistent definitions of what a species even is.

> Generally Neanderthals are pointed out as an exception to cross species fertility since...

There's no such rule and Neanderthals are not notable as an exception. Fertility is just a very rough proxy for genetic distance, which is correlated to our arbitrary "species" buckets but by no means a real line or hard rule. Many, many reasonably closely related species can interbreed, like jaguars and lions. Most of homo that had the opportunity could probably interbreed.

That's not the definition of species. Many species can interbreed, sometimes even species that are pretty distantly related.

We could make that the definition, but we'd doing a lot of redefinition: coyotes and wolves would become the same species, as would lions and jaguars. Fertility issues tend to increase with genetic distance but aren't guaranteed; for example, mules are usually but not always sterile.

> “Early humans” are still humans.

I respectfully disagree, as started in my earlier post. It would be nice if human language worked like that, but it does not always. A "stone frigate" isn't a boat, an "iron lung" isn't a respiratory organ.

Usage is definitely mixed, but I’m surprised you haven’t encountered this. From Wikipedia:

> Although some scientists equate the term "humans" with all members of the genus Homo, in common usage it generally refers to Homo sapiens, the only extant member. All other members of the genus Homo, which are now extinct, are known as archaic humans, and the term "modern human" is used to distinguish Homo sapiens from archaic humans.

Those things aren't closely related biologically, so not a good analogy. "Human" isn't a precise biological category, it's just based on how the word is used, unlike homo sapiens. And some people, including scientists, use it to mean closely related species of hominids. Or hominids generally.

I agree? I didn't know close biological relation was a prerequisite for a good analogy, but I'll gladly oblige: vampire squid, velvet ant, slipper lobster, naked ape.

Being 2.3% neanderthal, I'm... not sure what to think about it.

I think it's a case of the classic issue of trying to make sharp boundaries in a continuum. There just are no fully satisfying answers.

If you look closely at it, the concept of "species" is impossible to define exactly.

That's fine in general. Many words are like that. But it makes it flawed as a scientific concept.

If 500,000 years ago a hominid sits by the fire they lit and is working on sharpening a stone tool, would you say:

"someone / a person is sharpening a tool" or "it / a hominid is sharpening a tool"?

I personally would call them a human, but this seems like a false equivalence unless you believe that personhood is something exclusive to humans. “Someone / a hominid” is perfectly valid and could at the same time be “someone / a person”.

Bizarre, this is the first I've encountered the concept of someone thinking Neanderthals and Denisovans were "Human".

Allow me to further blow your mind:

https://www.nhm.ac.uk/discover/who-were-the-neanderthals.htm...

https://www.pbs.org/wgbh/nova/article/are-neanderthals-human...

What about the 2nd generation of mule, then 3rd? If the probability of viability keeps dropping generation after generation, eventually it will delete itself?

It doesn't work like that. Backcrossing it with one of the parent species (assuming fertility in the first place) as you'd expect tends to increase the likelihood of fertile offspring in proportion to the number of generations. And that's exactly what you'd expect in any hybridization event. And anyway, mules are actually pretty special in that horses and donkeys are actually fairly distant relatives (diverged 4 million years ago) and have different numbers of chromosomes. All members of homo (supposed to have emerged all more recently than 3 million years ago) could probably interbreed and the ones that had the opportunity probably did.

It's really unfortunate that schools tend to simplify the definition of species in this way, because it's just not really not meaningfully true at all. We could "make" it true by actually defining species this way (at least for animals) but it'd radically transform our taxonomies.