
We don't know which species should be classed as 'human' - JacobAldridge
http://www.bbc.com/earth/story/20160111-what-is-it-that-makes-you-a-human-and-not-something-else
======
ucaetano
"We don't know if Neanderthals count as humans, or if chimps do, because we
can't agree on the defining features of a human"

I don't think any scientist disagrees that chimps aren't humans. The issue in
question here is how far back in our lineage do humans go, vs. some other
species.

Given that evolution happens continuously, and not in a discreet way, it is
completely impossible to objectively determine precisely when we "became"
humans, something which is exacerbated by the fact that we're only looking at
fossils.

Perhaps, like porn, we should not try to define it further, but there's no
question that, when looking at today's existing species, you know a human when
you see "it".

~~~
aetheriality
holy triple negative man

~~~
ucaetano
I try my best :)

------
jedberg
This is very similar to a problem in linguistics (and in some ways "is" a
linguistics problem).

You can define what an acorn is, and you can define a tree, but when does an
acorn become a tree? Same with baldness. Everyone can identify a bald person
and likewise someone who isn't bald, but when do you go from not bald to bald?
This incidentally is part of the fundamental debate about abortion (when does
a fetus become a child?).

And it is the same here -- we can define a human and "not human" but we're
having trouble defining exactly when it goes from one to the next.

~~~
pc2g4d
I saw the linguistics connection as being that distinguishing one
genus/species from another is a very similar problem to distinguishing one
language/dialect from another. In both cases the population of organisms or of
language users doesn't break apart into disjoint subsets naturally---nobody
has a label within them saying "homo sapiens" or "Farsi speaker". These
distinctions are artificially imposed and ultimately arbitrary.

------
camelNotation
I think our difficulty comes from the fact that we are unable to admit how
exceptional we are. There is a fad at the moment, and it's been ongoing for a
century or more, to assign a degree of banality to the biological
classification of the human race.

The obvious problem we all have with this is that we are the ones doing the
assigning. I'm reading articles like this on a machine designed and built by
humans with, if nothing else, the ability to process mathematical equations at
a speed far beyond any normal human ability. We do things that are so
obviously exceptional and unique that to classify us alongside chimpanzees due
to DNA similarities strikes us all as absurd (because it is).

When the article points out that you wouldn't assign a separate genus to an
animal just because it uses tools, they're missing the fact that the
difference between a bird using a stick to fetch a seed and one that doesn't
is absurdly simplistic relative to LANDING ON THE F--KING MOON. At some point,
perhaps something that doesn't factor in for other animals should be factored
in for us due to the extreme amounts of difference between my DVR recorder and
the special rock a chimp uses break open a nut.

To me, this comes across as biological tunnel vision. Since the differences
between other animals fall into simpler categories like appearance and
genetics, biologists don't want to introduce something like "behavior" into
the mix for fear of it complicating the process. The problem is that in the
case of homo sapiens, behavior is an unbelievably big deal.

~~~
JoeAltmaier
Interestingly, neither you nor I can likely design a DVR or go to the moon.
The difference between us and other apes is, we can cooperate by the
thousands/millions to get something done. Maybe that's the critical
difference.

~~~
camelNotation
Agreed, that was the essence of what I was trying to say.

~~~
ethbro
If you one starts to look at the things we do as a classification, then it
gets very messy very fast.

I work on magic boxes all day and construct intangible realities that spit out
numbers. Am I still the same group as a member of a tribe untouched by modern
civilization in the depths of the Amazon?

What about the same group as Kelly Johnson? Tim Berners-Lee? Vint Cerf? Jack
Kilby or Robert Noyce? GalileoPascalNewtonFranklinEulerFourierMaxwellCurie?
MandelaDeKlerkMLKGandi?

It seems pretty presumptuous to say "we (as a pan-global diaspora) have
achieved great things, therefore we are all special."

~~~
JoeAltmaier
The assertion is, that we as a race are special, right? Not 'all'

~~~
ethbro
If not all then how can we as a race be special? I'd say that if we lump going
to the moon onto our collective accolades, so do we lump the Holocaust and
various other genocides.

My personal opinion, but it seems like there's a desire to overstate our
differences with "other animals." Which generally seems like a prelude to
exterminating them without feeling bad about it / trashing the environment /
generally believing in our manifest destiny and right to same as humans. But
that's my personal opinion.

~~~
camelNotation
I think you're reading more into my assertion than what was there. Don't
assume that superiority gives us the right to abuse (I would argue quite the
opposite) and don't assume that regarding ourselves as equal to other forms of
life will somehow lead to virtuous behavior (I would argue the opposite here
as well). However, those are debates of their own.

------
throw123421
This debate does not even scratch surface. And I find it bit unsettling.

Most Europeans could claim Neanderthal ancestry, because they shared genes.
Question if Neanderthals were human is not even theoretical.

Last Neanderthals walked 35K BC. There are tribes which were isolated for 50K
or more years. In theory they have a huge genetic difference, also their
morphological difference is big, Does that mean they are separate species?
Species are often recognized by their shape rather than genes, for example
grizzly and polar bear have practically identical genes.

And great apes? I find it insensible to make them humans, when 50% world
population does not have even basic human rights. In Western Countries dogs
have more rights than many people.

Bet lets assume that great apes are humans. Does it mean they have legal
obligations? Could chimpanzee go to prison for torturing animals (bush
babies). What if gang of chimpanzee kills other human?

------
cwal37
The book Sapiens: A Brief History of Humankind[1] is relevant here (which I've
been reading and thoroughly enjoying recently) if anyone wanted to seek out
some longer-form information on this and the topics around human evolution and
development. The semantics here are really interesting to me because the book
immediately points out that not too long ago there were at least 6 species of
human on earth at the same time (going by homo=humans, sapiens is what
distinguishes us). That concept had never been so explicitly stated to me
before, and I find it really fascinating to unpeel.

[1]
[http://smile.amazon.com/gp/product/0062316095/ref=s9_simh_gw...](http://smile.amazon.com/gp/product/0062316095/ref=s9_simh_gw_p14_d0_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=1K24M8JRJ3T3WBP81KD2&pf_rd_t=36701&pf_rd_p=2079475242&pf_rd_i=desktop)

~~~
Symmetry
That's quite a good book but I think that _The Secret of Our Success_ did an
even better job of zeroing in on what we can do that distinguishes us from
other animals.

[http://smile.amazon.com/Secret-Our-Success-Evolution-
Domesti...](http://smile.amazon.com/Secret-Our-Success-Evolution-
Domesticating/dp/0691166854/ref=tmm_hrd_swatch_0?_encoding=UTF8&qid=1452528949&sr=8-1)

------
BuckRogers
I was always under the impression that species are separated over whether they
can breed together successfully or not.

I honestly didn't think it needed to be such a big debate and thought this was
long settled. "Can they interbreed?" and if the answer is no, it's a different
species.

~~~
Retric
The natural question is then what about Ring species? With populations A, B,
and C. A-B can breed, B-C can breed, but A-C can't.

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

~~~
defiblep
As a thought experiment, if you imagine ring species in time almost anything
can "breed" with almost anything else.

Eg each human can breed with a human in the previous generation. Each chimp
can breed with a chimp in the previous generation. Right back to their common
ancestor.

As long as there's a common ancestor, there should be a viable chain to be
followed in most cases.

------
oniMaker
I'm more interested in who we classify as people. Remember, the word person
comes from persona, meaning an actor's mask.

In 2014 it was discovered that a species of Long-finned pilot whales (a type
of dolphin) has more neocortical neurons than humans by a factor of two! The
neocortex is an area of the brain associated with language and conscious
thought.

Do these dolphins count as people? Should we afford them "human" rights? What
about other species?

The pig you eat has the same amount of neurons in her cerebral cortex as your
cat and dog put together. The cow, more than all three put together. Are they
people?

~~~
Spivak
Trying to define personhood using any sort of scientific analysis is a
dangerous road that was/is used to justify horrific acts of racism, violence,
and subjugation, including Social Darwinism in the early 1900s, and the
eugenics movement that followed.

I can think of no objective testable definition of person which is both
meaningful (i.e. non-trivial) and not horrific for corner cases or those that
would be excluded.

I know this wasn't your intention because you're using it to grant personhood
to more entities but the implications aren't great regardless.

~~~
oniMaker
No, this is the wrong approach. The object is not to define personhood through
some objective set of criteria which can then be used to justify evil; it's to
use our observations about the world to arrive at a broader and more humane
outlook.

The argument itself is wrong as well. If some method X is used for evil, it
does not mean X is intrinsically evil.

This is essentially the same flawed argument that's used against many areas of
science.

------
VLM
Needs more politics. Not even kidding. Enormous arguments over nothing can be
very superficially covered by journalists, but the real, dramatic story is
someone might get kicked out of some human studies department or funding grant
or chair because fossil XYZ is, or is not, a human fossil. Or someone is
agitating for, or against, a department schism creating a new "almost but not
really human" department of studies with the right or wrong person as highly
paid chair of course in competition with the legacy department. Or someone's
tenure depends on rabble rousing enough to get publicity to be seen as
relevant. Or someone's hiring or tenure has to be denied for various
acceptable or unacceptable demographic membership reasons or maybe just
trivialities (this is academics after all) and they need a highly dramatic
cover story. Maybe some public museum only gets financial funding for "human
fossils" and there's a condo developer eyeing that block of land for
redevelopment, and it sure would be convenient if the money dried up.

There's probably a real dramatic story underneath the argument, but the
journalist somehow managed to miss it.

------
lisper
"But this conventional definition is not necessarily correct."

Definitions (by definition!) cannot be "correct" or "incorrect". They can only
be more useful or less useful.

------
jonstewart
So what? I'll take Semantics for a half-penny, Alex.

~~~
rangibaby
That was my first reaction, but pursuing knowledge for its own sake can lead
to fantastic discoveries. Imagine if they found that a species that was
considered the same as humans until now was actually different and from Mars
or had a gene that cured cancer.

~~~
dsjoerg
knowledge is great. i am pro knowledge. on the other hand, arguing about the
definition of an emotionally charged term such as "human" is not so great.
reminds me of the argument about whether or not Pluto is a planet.

------
wtbob
> Either way, [Linnæus's choice of words implied that humans are fundamentally
> different from everything else … It is an understandable mistake …

Ummm, I'm pretty sure that it wasn't a mistake. Human beings _are_
fundamentally different from anything else on this planet. If you seek a
proof, look around.

~~~
vudu
The more resistant you are to the idea we are unique the more human you may
be.

------
juntsao1030
I know! In the past, whites are called "human". Now, rich people are called
"human". I am also colored and I am not a racist. Every century has its own
definition on the word, "human", no matter in biology or sociology.

------
profinger
This has been solved.

Featherless biped with broad flat nails.

lol

EDIT: For the record, this was said to be Plato's definition of a human after
Diogenes (probably my favorite philosopher/practical joker) brought in a
plucked chicken and called it a "man" in response to Plato's original
definition of humans as "Featherless bipeds"

------
kolbe
Just because we crafted the shoe, doesn't mean we'll make a foot fit in it.
"Humanity" is more of an abstract concept that science is usually comfortable
with. I think we should look for things to define, and create a word rather
than create a word, and then figure out how to define it.

------
aetheriality
if the living being can naturally procreate with me without technological or
medical assistance, and generate an offspring that can also naturally
procreate upon reaching maturity, then for sure that living being is human.

~~~
wavefunction
As far as I know purebred standard British Bulldogs cannot reproduce without
artificial insemination due to their body type making it physically
impossible. Your definition would indicate that two British Bulldogs are not
even part of the same species, and likely other dogs with mis-matches in
physique.

------
lolc
I'm with the lumpers because I like the idea of having chimps in my genus. But
if the splitters prevail I won't cry a tear over it.

------
tokenadult
It's useful in this context, after reading the BBC story kindly submitted
here, to go to a webpage by a biology professor, Jerry Coyne, who literally
wrote the book on speciation and definitions of species.[1] He wrote, in his
webpage follow-up to a professional lecture for other biologists,[2]

"But I want to discuss briefly a shorter second piece by Gibbons in the same
issue of Science, 'The species problem.' Here she brings up the controversy
about whether modern humans, Neandertals, and Denisovans were members of
different species or the same species. This question is far more important in
dealing with humans than, say, with fruit flies, simply because there were far
fewer types of hominins, and anthropologists’ careers depend on whether or not
they name a new species. That’s why there are so many species names in the
hominin family tree—names that turn on characters as tiny as a few millimeters
in the measurement of a tooth. It’s likely that, several million years ago,
three or four species of hominin did exist at the same time—and maybe at the
same place—giving rise to fanciful scenarios about war and (especially) inter-
group mating. . . .

"But that was more than a million years ago. What about the more modern groups
of _Homo_ , like Neandertals? According to Ernst Mayr’s biological species
concept, which Gibbons describes, individuals are members of the same species
if they can mate with each other when they encounter each other in nature,
and, critically, produce fertile, viable hybrids. If they can’t, then there
must exist genetic barriers to mixing of genes, the so-called 'reproductive
isolating barriers' that maintain the integrity of species."

With that issue clarified, we see that anthropologists who find bones in the
ground will always have incentive to be "splitters," identifying more rather
than fewer species, and the only way to resolve how many species there were is
to figure out which ancient hominids could mate and produce viable offspring
who in turn could mate again and again produce viable offspring for more
generations.

Studies of ancient DNA used to be impossible. It was a big breakthrough the
first time an Egyptian mummy (plainly a modern human) had its DNA sequenced.
The DNA sequencing of a Neanderthal[3] was a further breakthrough. It's plain
now that Neanderthals and "modern humans" were part of the same biological
species. The usual reckoning is that any modern human with traceable ancestry
to Europe or to Asia probably has genes and gene combinations characteristic
of Neanderthals, which have since spread further all over the world.

We are all closely related, and we are related to a great variety of ancient
human fossil samples. Where human artifacts and cultural ideas travel, human
genes travel, and we are all much more "mixed" and interrelated than people
imagined even a decade ago.[4]

[1] _Speciation_ by Jerry A. Coyne and H. Allen Orr

[http://www.sinauer.com/speciation.html](http://www.sinauer.com/speciation.html)

[2] "How many species of humans were there?"

[https://whyevolutionistrue.wordpress.com/2011/01/28/how-
many...](https://whyevolutionistrue.wordpress.com/2011/01/28/how-many-species-
of-humans-were-contemporaries/)

[3] [http://humanorigins.si.edu/evidence/genetics/ancient-dna-
and...](http://humanorigins.si.edu/evidence/genetics/ancient-dna-and-
neanderthals/sequencing-neanderthal-dna)

[4] "Towards a new history and geography of human genes informed by ancient
DNA"

[http://biorxiv.org/content/biorxiv/early/2014/03/21/003517.f...](http://biorxiv.org/content/biorxiv/early/2014/03/21/003517.full.pdf)

~~~
lisper
"anthropologists’ careers depend on whether or not they name a new species"

This, I think, is really the crux of the matter. The process of answering the
titular question has more to do with economics than biology.

