

Skull of Homo erectus throws story of human evolution into disarray - yread
http://www.theguardian.com/science/2013/oct/17/skull-homo-erectus-human-evolution

======
tokenadult
The reporting in this story left untouched some details I wanted to see
follow-up on, so I decided to look at some other journalistic and blogger
accounts on the same newly published research report. Brian Switek's story on
National Geographic

[http://news.nationalgeographic.com/news/2013/10/131017-skull...](http://news.nationalgeographic.com/news/2013/10/131017-skull-
human-origins-dmanisi-georgia-erectus/)

is quite helpful and has interesting graphics.

The BBC story

[http://www.bbc.co.uk/news/science-
environment-24564375](http://www.bbc.co.uk/news/science-environment-24564375)

looks to be more helpful than the story kindly submitted here, the CNN story

[http://edition.cnn.com/2013/10/17/world/europe/ancient-
skull...](http://edition.cnn.com/2013/10/17/world/europe/ancient-skull-human-
evolution/index.html)

quotes other experts who don't reach the same conclusions, while the Wall
Street Journal story

[http://online.wsj.com/news/articles/SB1000142405270230438410...](http://online.wsj.com/news/articles/SB10001424052702304384104579141600675336982)

largely quotes scholars who agree with the new announcement from Georgia.

The Bloomberg story

[http://www.chicagotribune.com/news/sns-wp-blm-news-bc-
skulls...](http://www.chicagotribune.com/news/sns-wp-blm-news-bc-
skulls17-20131017,0,1615390.story)

quotes an expert who sums up what the real issue is here:

"The finding likely won't change expert's views on species diversity, where
two groups are heavily entrenched said William Harcourt-Smith, an assistant
professor at Lehman College and a research associate in the American Museum of
Natural History's Division of Paleontology.

"Some, nicknamed 'splitters,' see the tree of evolution as having many
species. Others, called 'lumpers,' see wider species categories and fewer
limbs on the tree.

"'To be honest it just adds some important fuel to the debate,' Harcourt-Smith
wrote in an e-mail. 'The lumpers, of course, will love this new paper, but I
can see splitters saying that there is too much variation in both the African
early Homo and Dmanisi sample for them to all be Homo erectus.'"

~~~
masklinn
I love this quotes on splitters v lumpers:

> splitters make very small units – their critics say that if they can tell
> two animals apart, they place them in different genera … and if they cannot
> tell them apart, they place them in different species. … Lumpers make large
> units – their critics say that if a carnivore is neither a dog nor a bear,
> they call it a cat.

------
pbhjpbhj
TBH I've always thought that variations in skulls unearthed and labelled as
different genus seemed not to be _that_ varied next to the variation in modern
people. About a year ago I tried to unearth a visual comparison that would
show the variation of "modern" skulls so it could be compared - anyone know of
such a work?

It's the same mistake made with the dinosaurs (see eg
[http://www.ted.com/talks/jack_horner_shape_shifting_dinosaur...](http://www.ted.com/talks/jack_horner_shape_shifting_dinosaurs.html))
assuming that one can tell how an animal grew by analogy and that
heterogeneity necessarily shows speciation.

Is this really the first time that differently formed skulls have been found
together in an archaeological dig. That's surprising isn't it?

Equally well, just because 5 skulls were found together why does one then have
to declare them all to be H.Erectus, presumably there are other methods of
categorisation relied on to establish that point?

~~~
waps
Because if they died together, they're part of the same group. If some are
small skulls (ie. children) and some adults (a family that died in a natural
disaster, landslide, ... say), then they obviously interbreeded, at which
point they would be re-classified as only one species, and maybe something
other than genetical differences account for the differences in skulls.

------
baddox
Is this anything other than the species problem [0]? Based on this quote:

> "If you found the Dmanisi skulls at isolated sites in Africa, some people
> would give them different species names. But one population can have all
> this variation. We are using five or six names, but they could all be from
> one lineage."

it sounds like it's just a semantic question of how exactly the "species" are
divided up logically.

[0]
[http://en.wikipedia.org/wiki/Species_problem](http://en.wikipedia.org/wiki/Species_problem)

~~~
netcan
Well, inevitably its partly that.

But it seems there are is a real finding here even if we avoid the word
species entirely. Basically it's evidence of morphological diversity within
even a very narrow definition of the word species. If you know that bulldogs
and Yorkshire terriers are the same species it's a lot easier to argue that
your fossil of a great Dane is too, even though it looks very different. That
means you don't need millions of years to evolve it. If the diversity is there
in the species, selective pressures can make a different looking
variety/subspecies quickly.

Modern humans are not that diverse in size. An adult males weigh 50-85kgs. If
you find a population of individuals weiging 120ks, you will conclude that
these are probably a different species.

~~~
tjr
_Modern humans are not that diverse in size. An adult males weigh 50-85kgs. If
you find a population of individuals weiging 120ks, you will conclude that
these are probably a different species._

Haven't been in the U.S. much, have you? :-(

~~~
001sky
_At least one in two people are now overweight or obese in more than half of
the 34 OECD countries_

------
lkrubner
This is a very strange sentence:

"Homo is the genus of great apes that emerged around 2.4m years ago and
includes modern humans."

That is not a normal way to describe the ancestry of humans. In between apes
and humans were the Australopithecus:

[http://en.wikipedia.org/wiki/Australopithecus](http://en.wikipedia.org/wiki/Australopithecus)

The genus homo is usually said to have started with homo habilis:

[http://en.wikipedia.org/wiki/Homo_habilis](http://en.wikipedia.org/wiki/Homo_habilis)

Normally one doesn't refer to one genus as being part of another genus.

Also the date "2.4m years ago" is controversial. If homo habilis is
reclassified as australopithecus, then the genus homo emerges much more
recently than 2.4 million years ago.

~~~
pygy_
_> "Homo is the genus of great apes that emerged around 2.4m years ago and
includes modern humans."_

This implies that we are apes.

Quoting Wikipedia:

 _The composition of a genus is determined by a taxonomist. The standards for
genus classification are not strictly codified, so different authorities often
produce different classifications for genera._

~~~
svachalek
We are apes.

[http://en.wikipedia.org/wiki/Great_Apes](http://en.wikipedia.org/wiki/Great_Apes)

~~~
pygy_
I'm glad to know it's official :-)

------
haberman
I'm amazed that we are still finding new fossils all the time. What is the
story usually like of how this happens? Farmer digs a hole for a fencepost,
finds a weird skull, calls 1-800-ANTHROPOLOGIST? I'm being flippant but I'm
genuinely curious how fossils like this continue to be discovered.

~~~
StavrosK
This is entirely unrelated, but a cool story nonetheless (too bad the details
elude me, I will make them up): There was a big archaeological site discovered
in an island in Africa, and archaeologists needed to search a large area for
findings. They asked locals to help, and paid them for every piece of ancient
artifact they would find and bring back.

The locals started smashing large ancient vases and statues they found into
small pieces to get paid more.

~~~
mikeash
You always have to be careful about what you incentivize. There are similar
classic stories about bounties on cobras and rats which resulted in breeding
more cobras and snakes:

[http://en.wikipedia.org/wiki/Cobra_effect](http://en.wikipedia.org/wiki/Cobra_effect)

------
jcromartie
Doesn't this potentially simplify the story?

~~~
wintersFright
Agree, the title is link bait for creationists

~~~
sambeau
Of course, this is a British publication and so this wouldn't have occurred to
the headline editor. It certainly didn't occur to me until you mentioned it.

Most Brits would read that as disarray about the timeline of human evolution,
not a challenge to the 'story'.

~~~
jcromartie
[previously-deleted comment]: I wonder what it's like to live in a country
where you don't have to give a second thought to statements based on
potentially massive differences in beliefs about the age of the universe.

~~~
petegrif
Turn that question around - "I wonder what it's like to live in a country
where you don't have to give a second thought to statements derived from
scientific investigation rather than religious dogma then move to the US?'

I can answer that one for you. It's shocking. I had no idea, nor do I believe
that most Europeans have any idea, just what a strong hold primitive
interpretations of religion still holds over a huge percentage of a developed
first world society.

~~~
rafcavallaro
The US is economically first world but cognitively third world :)

------
sambeau
This is an interesting problem: should you err on the side of creating new
species every time you find a bone fragment or should you assume it is more of
the same?

I think I come down on the side of those who create new species until
sufficient evidence can be found to merge them. It strikes me as better
science — a connection is, to my mind, more significant than a lack of a
connection.

~~~
masklinn
> This is an interesting problem: should you err on the side of creating new
> species every time you find a bone fragment or should you assume it is more
> of the same?

That is an extant fight in taxonomy, and one which has been going on for more
than a century and a half:
[http://en.wikipedia.org/wiki/Lumpers_and_splitters](http://en.wikipedia.org/wiki/Lumpers_and_splitters)

> splitters make very small units – their critics say that if they can tell
> two animals apart, they place them in different genera … and if they cannot
> tell them apart, they place them in different species. … Lumpers make large
> units – their critics say that if a carnivore is neither a dog nor a bear,
> they call it a cat.

~~~
comrade_ogilvy
Heck, how to classify even existing living and breathing specimens is not
always clear. Genetic sequencing has resolved some, but not all, such
questions.

Fundamentally, there is no obvious and unambiguous definition of "species". It
is a functional definition that is highly useful, but it is not exactly
predictive is every case under the sun. There will always be confusion on the
margins, because the natural world is sometimes messy that way.

------
scottmagdalein
Scientists, if carbon dating is limited to ~50,000 years or so, how do
archeologists date things into the millions of years with accuracy?

~~~
phansch
Carbon dating is just a subset of radiometric dating. You can leverage the
decay rates of (almost) any element to estimate the age of an object.

([http://en.wikipedia.org/wiki/Radiometric_dating#Fundamentals...](http://en.wikipedia.org/wiki/Radiometric_dating#Fundamentals_of_radiometric_dating))

~~~
madaxe
Also stratification and artefact context.

