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Comment by njharman | Hacker News Reader

Something I've never understood (since highschool some 30 years ago) is; when getting partial skeletons perhaps from only a single individual, how can they claim new species? I mean what's diff with that and some hypothetical future anthropoligist looking at siberian with roundish skull thicker brow ridges and that of six foot tall masai with long face and then a sub 5 foot native peruvian and declaring them all different species?

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I think the problem is the "species" construction itself. Remember, it's completely made up by people and has no obligation to reflect the sometimes messy reality on the ground.

I'm more interested in what we can learn about these people (using the term for convenience) than what they are called. When did they live? How much genetic distance is there between us and them? Do modern humans carry some of their genes? Could they speak?

I do seem to remember being taught in school that the definition of species is "organisms that can reproduce and generate fertile offspring".

Apparently, though, it's not that simple: https://en.wikipedia.org/wiki/Species_problem

That's a problematic criterion when trying to classify long extinct species. We can hypothesize, and perhaps there is a point where we can confidently say "These two definitely couldn't mate" (e.g. Australopithecus afarensis and Homo neanderthalensis), but there's always going to be a large gray area. In fact, here's an interesting quote from the OP article:

> A small group of Homo sapiens left Africa 60,000 years ago and settled the rest of the world, replacing the other human species they encountered (with a small amount of interbreeding).

So actually, it seems we are confident that Homo sapiens was capable of reproduction with some of the other "species" we've identified.

It's easy to see why it's a problem when we look into the past. Presumably, every creature should be considered to the be the same species as its parents. But go far enough back and your N-great grandparents are undeniably a different species.

If we had a record of every organism that had ever lived, trying to classify them into "species" would be a ridiculous task -- regardless of how punctuated-equilibriumy things are. Since the fossil record is fairly spotty, it's only a slightly ridiculous task.

> I do seem to remember being taught in school that the definition of species is "organisms that can reproduce and generate fertile offspring".

Which is problematic for extinct animals. We have no way of knowing if modern humans would be able to produce offspring with Neanderthals, for example.

The current body of evidence suggests that we could and did, since Neanderthal DNA is present in some modern humans [1].

[1] http://www.bbc.com/news/science-environment-33226416

That suggests we did. It doesn't necessarily suggest we still could. Nicely illustrates why speciation is more complex than "can't interbreed" though.

I call them a Neanderthal "race' not species. Then it might be unclear how different they appear from modern man.

No, we know humans have produced viable offspring with neanderthals in very recent evolutionary past (30,000 years).

While the human species has changed during that time, no doubt we are still interfertile with neanderthals.

If you do a genetic test with 23andMe, they will tell you exactly what percentage of Neanderthal DNA you have.

Actually, I think we do, DNA, and the answer is yes.

Yeah, not that simple at all. To me though, the problem isn't the difficulty of defining the species. The problem is peoples' need to classify things (a problem that goes far beyond scientific classifications). But I recognize that I'm in the minority in that view.

Species is really a misapplied concept when you look at one current lifeform's ancestry. Everything is a "ring species" with some sufficiently old ancestor.

What's stopping a future anthropologist from declaring siberians and pygmies to be different species? It's not done now for political reasons, but the future has no reason to be concerned with the past's special sensitivities.

Consider that "spanish" and "italian" are officially separate languages, while the US and Scotland both officially speak "english". The terminology won't help you predict which pair has an easier time communicating. It's political.

> What's stopping a future anthropologist from declaring siberians and pygmies to be different species?

The fact that they are capable of producing fertile offspring ?

But then you have ring species such as some seaguls. The gulls in Northern Europe can interbreed with the ones in Canada, which can interbreed with the ones in Alaska, which can interbreed with the ones in Siberia, which cannot interbreed with the ones is northern Europe. So is there one species or two, and if two where do you draw the line?

I would surmise the answer is N-1 where N is the number of separate gull groups. A species would then consist of two gull groups who can mate and this answer assumes there are no mini circles or triangles in the ring.

No idea the academic answer though.

By that definition a particular individual could simultaneously be a member of two species.

Fascinating !

https://en.wikipedia.org/wiki/Ring_species

I think the point was: how can you know that when you only have a few kg of bone fragments?

I am more concerned with the scientific racism (https://en.wikipedia.org/wiki/Scientific_racism#United_State...) emanating from that post.

Taking that as the metric how have the writers of the paper in the OP proved that the species that produced these bone fragments was not able to produce [fertile] offspring with any other species (of which they have a few bone fragments), or even with modern humans.

Even with a full genome, or a full skeleton is it even possible? Surely the only way we currently have to determine mating compatibility is to have live subjects to mate/extract gametes from and means to incubate the zygote [and care for it to adulthood].

> Consider that "spanish" and "italian" are officially separate languages, while the US and Scotland both officially speak "english". The terminology won't help you predict which pair has an easier time communicating.

I'm not certain, but that doesn't sound right to me.

I'm pretty sure Americans and Scots have a far easier time communicating than someone who only speaks Italian and someone who only speaks Spanish.

(Assuming Scottish accents that are reasonably mainstream, not an extreme outlier.)

If I'm wrong, I'd like to be enlightened.

I'm Scottish by birth, but was raised in the US. I don't have a problem with any of the Scottish accents, but American friends consistently have trouble understanding Glasgow patter and certain highland accents. Heck, I add a roommate in college who needed captions for Trainspotting!

That said, it tends to be as much a vocabulary problem as the accent itself. Lot's of colloquialisms to learn.

Correct. Italian and Spanish can understand each other, but with a lot of effort and keeping communication at a very basic level. This thing that we can speak to each other easily is a myth. That said, we can learn each other languages in a matter of weeks.

> we can learn each other languages in a matter of weeks

Not so fast. Even if you limit yourself to a vocabulary made of the most common 10000 words, you still need a lot more practice to differentiate between nouns that have a gender in Italian and another in Spanish, irregular verbs, idioms, etc.

Understanding a language is one thing. Speaking and writing it is a whole new level.

Gendering nouns that aren't actually gendered is one of the stupidest concepts humanity has inflicted on itself.

> Gendering nouns that aren't actually gendered is one of the stupidest concepts humanity has inflicted on itself.

The objects referred to by nouns aren't inherently gendered, gender is a feature of grammar (sex is a feature of some classes of objects, and fairly recently the grammatical term was adopted as a euphemism for sex by people afraid of the word "sex", and even more recently, inspired by that use, as a name of a social construct associated with, but distinct from, biological sex.)

But grammatical genders, while in some languages they have some correlation to sex distinctions, have no necessary relation to them, as gender distinctions may be on other axes entirely.

So the whole statement seems based on not understanding what "gender" is at all.

> So the whole statement seems based on not understanding what "gender" is at all.

Your parent was just saying gender is unnecessary, and you did not answer anything to disprove that, or to prove that they were once needed.

For instance (speaking of Latin), why is Lapis (stone) masculine but Saxum (stone) neuter?

The Romans could have chosen to place all new words on the 2nd declension neuter (the simplest) but instead it (Classical Latin) created 3 more 3rd declension variants on top of the existing ones! And it was more productive, in this 3rd declension, in assigning masculine and feminine rather than neutral, which the 3rd declension also supported!

So what is the reason for that?

A few great comments from /r/linguistics on Reddit really enlightened me on this topic.

Gender isn't senseless, it's a checksum strategy for information. It's not even about sex, lots of grammars have genders that have nothing to do with male/female. The point of gender is agreement: if you're talking about something female, all verbs, adjectives, and adverbs in the sentence have to agree, or the listener gets a syntax error. The syntax error helps the listener figure out that they missed something, or that the transmission was garbled. https://www.reddit.com/r/linguistics/comments/3i1695/eli5_wh...

If you get rid of gender, as English mostly has, you end up forced to adopt different constraints that seem equally arbitrary and wasteful, like strict word order and lots of prepositions. https://www.reddit.com/r/linguistics/comments/3i1695/eli5_wh...

Very excellent comment demonstrating the point about English and word order - in Russian, you can say three words that mean "the dog saw the rabbit" in every possible order, and it's still a valid sentence that means the same thing, because Russian doesn't depend on word order. If it was English, "the dog saw the rabbit", "saw the rabbit the dog", "saw the dog the rabbit", "the rabbit the dog saw", and "the dog the rabbit saw" would all mean exactly the same thing, unambiguously, because the gender of "dog" would have to match the gender of "saw". https://www.reddit.com/r/linguistics/comments/1kdxsc/are_the...

I'm sorry, but that still does not explain why the Romans created more gendered 3rd declension variants when using the neuters from the 2nd and 3rd declensions would have made more sense (since the things they were naming were sexless, like rivers and trees and other geographical things) while they would nevertheless have retained the "checksum" and "free word ordering" benefits from a language that declines its nouns.

For example, Finnish is utterly genderless, but it has more declension cases for nouns than Latin had. And so, Finnish affords itself the ability to have free word order and checksum benefits while doing entirely away with the concept of gender.

So I reject your explanation on the basis that it is clear to me that the declension of nouns into cases is what is responsible for the checksum and word order benefits, and not whether a language has grammatical gender.

> For example, Finnish is utterly genderless, but it has more declension cases for nouns than Latin had.

That's consistent with simply making a tradeoff. So a Roman could say:

I don't understand why the Finns created more declension cases when they could have just used gender.

The free word order seems to come predominately from declension rather than gender, but I don't see how declension provides much in the way of a checksum.

I think it's a mistake to think of natural languages as being rationality, deliberately constructed. They evolve organically, most often without -- and often in direct resistance too -- conscious design efforts. Elements of language are sometimes imposed by deliberate, premeditated campaigns, but these tend to be the exception rather than the rule.

Languages aren't generally products of design.

I suspect that sometimes we deliberately complicate our languages to make it harder for the less educated classes to speak them properly, thus creating a larger barrier between us and them.

It's not. Even Old English had grammatical gender, you just lost it with time, along with proper vowel pronunciation ;-)

Spanish and Italian are MUCH more different than American English and Scottish(?) English.

He was probably thinking of Scots: A 2010 Scottish Government study of "public attitudes towards the Scots language" found that 64% of respondents (around 1,000 individuals being a representative sample of Scotland's adult population) "don't really think of Scots as a language" (Wikipedia)

As the saying goes, a language is a dialect with an army and a navy.

It's a political thing. Species definition is messy, to the point of absurdity.

Indeed, the differences between long-separated human populations are such that even non-racist scientists acknowledge subspecies..

http://dienekes.blogspot.sk/2009/09/is-homo-sapiens-polytypi...

Thanks for posting this. It has always baffled me that we are led to believe that all of humanity springs from one common root. Absolutely ridiculous and goes against common sense -what other species (of anything) has just one single representative??? Who's been selling this and why???

Nobody is saying there was a single pair of people at some point. But something like a population bottleneck resulting from the Toba eruption would mean all future people were descended from a small group of survivors.

And those types of events happen a lot.

Small group?

It went down to estimated 1500 worldwide. That is plenty.

Note that last common ancestor of the most differing human ethnics is something like 180-200k years ago.

Furthermore, with the advent of denser living and agriculture, evolution sped up quite a lot.

> Who's been selling this and why???

The New York Intellectuals, who were connected to the Frankfurt School, who got the baton from Psychoanalysis.

Read The Culture Of Critique by Kevin Macdonald and you will have precisely your answer.

Ideas like Mitochondrial Eve are really popular, and also really popularly misinterpreted.

If species were based on bone structure, how many species of dogs would there be?

I still think it's super weird that they don't count as different species.

There's the suggestion that breeding + fertile offspring is the main concern, but couldn't early humans and neanderthals reproduce, for example? But we definitely consider them separate species.

Dividing lines are hard here I guess.

> couldn't early humans and neanderthals reproduce, for example?

Common misconception, but no, they couldn't.

I have the impression that current research by Svante Pääbo shows they likely did.

Huh, so it is. I took a few courses on prehistoric humanity and the evolution of mankind in college, but I guess I'm out of date.

(Thanks for not being the sibling poster in your response, BTW. "You are wrong." Hurf.)

You are wrong.

http://news.discovery.com/human/evolution/how-neanderthal-dn...

Every couple of rounds of PHD dissertations that notion changes.

The biggest support is a skeleton of a child which is believed to be a hybrid of Neanderthals and Homo Sapience but the morphological bone evidence isn't that conclusive.

http://news.discovery.com/human/evolution/neanderthal-skelet...

What i really don't like about that article is about how they phrased it the mDNA wasn't "Neanderthal", it just had markers which are rare in modern humans, some of those marker also appear mapped mDNA of "Neanderthals".

mDNA aside general genetic markers is a much weaker theory mostly because we cannot estimate well enough how much of the DNA in question actually came through inter-breeding and how much of it might actually survived from a previous common ancestor, or how many of them are just random mutations that survived through natural selection or cultural selective breeding. Because there have been claims before about that like that the gene for readheads came from Neanderthals but then was discovered that that specific mutation is just naturally occurring for humans and the redhead gene of modern humans isn't the same for Neanderthals or other primates.

The 1-4% neanderthal DNA is also a bit well iffy, comparing genomes is very tricky and those comparisons often strip away all the large differences e.g. like humans and chimpanzees only share 99% of the genes when you strip about 2/3rd of the genome.

So while there might have been interbreeding there's very little of actual evidence to point to the extent and the cause of it, could've been social interbreeding, could've been pillage and rape, could've been small isolated cases, could've been widespread, but PC gen-Y notions aside the science isn't really clear on on side or the other and it's hard to know if it ever will be able to be.

Geographic and chronological/geological isolation probably play a role. Populations separated by kiloyears and megameters are probably more likely to be considered species.

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