I’ve updated my post on the supposed evidence of Homo sapiens in Israel 400,000 years ago. We have a better idea of where this worldwide meme got started, and what the scientist behind the paper thinks about what happened…

I’ve been baffled by the spread of a non-story over the past couple days, about the supposed discovery of the oldest fossil of our species, doubling the age of our species from 200,000 years to 400,000 years and overturning the generally-accepted idea that Homo sapiens evolved in Africa.

Here’s a typical report, from the Associated Press:

Researchers: Ancient human remains found in Israel

JERUSALEM—Israeli archaeologists said Monday they may have found the earliest evidence yet for the existence of modern man, and if so, it could upset theories of the origin of humans.

Got it?

The hook for this story is the publication of a paper in the American Journal of Physical Anthropology. Did the reporters who hyped this story actually look at the paper itself? I have to wonder.

Let me quote a few pieces from it. You tell me where the scientists actually claim they have identified 400,000 year fossil of Homo sapiens.

Here is the abstract (I’ll define a few terms and give context afterwards):

This study presents a description and comparative analysis of Middle Pleistocene permanent and deciduous teeth from the site of Qesem Cave (Israel). All of the human fossils are assigned to the Acheulo-Yabrudian Cultural Complex (AYCC) of the late Lower Paleolithic. The Middle Pleistocene age of the Qesem teeth (400–200 ka) places them chronologically earlier than the bulk of fossil hominin specimens previously known from southwest Asia. Three permanent mandibular teeth (C1-P4) were found in close proximity in the lower part of the stratigraphic sequence. The small metric dimensions of the crowns indicate a considerable degree of dental reduction although the roots are long and robust. In contrast, three isolated permanent maxillary teeth (I2, C1, and M3) and two isolated deciduous teeth that were found within the upper part of the sequence are much larger and show some plesiomorphous traits similar to those of the Skhul/Qafzeh specimens. Although none of the Qesem teeth shows a suite of Neanderthal characters, a few traits may suggest some affinities with members of the Neanderthal evolutionary lineage. However, the balance of the evidence suggests a closer similarity with the Skhul/Qafzeh dental material, although many of these resemblances likely represent plesiomorphous features.

These teeth are from a site that’s between 400,000 and 200,000 years old in Israel called the Qesem Cave. Archaeologists have been working at the site for years now, bringing forth tools that some kind of hominin was using to cut up meat. Now researchers have found a few teeth from the site, in the older layers.

Hominins–that is, species closer to us than to chimpanzees–left fossils during this period all over the Old World, from South Africa to England to Java. They all clearly belong to our own genus, Homo. They share a number of key traits, including big brains, small teeth, and many other subtler but more diagnostic traits. But which species of Homo do they belong to? Here’s where things get tricky. A lot of fossils in East Asia are similar enough to one another that they’re considered one species, called Homo erectus. But some fossils from China from this age don’t fall so neatly into this group. Are they another species? Are they just an odd subspecies of H. erectus? A firm answer is hard to find.

Over in Europe, hominins first arrived 1.2 million years ago. At 400,000 years ago, the fossil record in Europe includes a species known as Homo heidelbergensis. Among other things, it is the first species known to make wooden spears. Some fossils from Asia and Africa resemble H. heidelbergensis, too.

Now, let’s turn the clock forward on each continent…

In Europe, the H. heidelbergensis fossils start to look a lot like Neanderthals. By about 200,000 years ago, the fossil record in Europe contains full-blown Neanderthals.

In Asia, H. erectus holds on 200,000 years ago, although there are other fossils that look like they might belong to H. heidelbergensis.

In Africa, H. heidelbergensis and other hominins give way to the first full-blown Homo sapiens fossils. These are fossils that have a number of different traits that link them clearly to us, and distinguish them from other hominins. (Here are details on two important ones: Omo and Idaltu)

There were probably other lineages of hominins living at the same time as well–such as the Denisovans of East Asia.

What about the region around Israel, where the new teeth come from?

The fossil record offers a picture of hominins evolving in Africa, and pulses of new lineages rolling out through Israel and neighboring regions, and then onward to Europe and Asia. Some 1.4 million years ago, for example, a species of early Homo left fossils in Israel at a site called Ubeidiya. At several sites in and around Israel, paleoanthropologists have found fossils and tools dating back 400,000 to 200,000 years ago–the same period as the Qesem site.  Unfortunately, the fossils are mostly fragments that might belong to a number of different species. The tools are equally ambiguous.

Something really interesting happened later in Israel, between about 130,000 and 50,000 years ago. It appears that Homo sapiens, having evolved in Africa, expanded tentatively into the Near East for the first time.  Fossils of tall, slender Homo sapiens turn up at a site called Skhul/Qafzeh. But then they vanish, replaced for tens of thousands of years by Neanderthals. Only later does Homo sapiens expand again out of Africa, and this time they don’t retreat. Instead, it’s the Neanderthals that disappear from the Near East, dwindling away to refuges such as Spain before becoming extinct.

The new paper documents the struggle of the scientists to figure out who the Qesem teeth belong to. In some ways, they seem more like Neanderthal teeth. In others, they seem more like the choppers of Homo sapiens, as represented by the Skhul/Qafzeh fossils. The authors tilt towards a relationship with Homo sapiens, but mostly because the teeth are “plesiomorphous.” That term refers to a trait that was already present before the origin of a group of species. It does not refer to a trait that closely links all individuals who have it into a single lineage.

Here’s a simple example of what plesiomorphous means. Let’s say you find a fossil at a site where you had already found dogs and birds. The new fossil has four legs. In that respect, it’s more like a dog than a bird.

But it would not make sense for you to conclude that the fossil was a dog. The common ancestor of dogs and birds had four legs, and birds evolved into two-legged animals. But alligators have four legs, too, and they’re closer to birds than to dogs. All those four legs really tell you is that the fossil isn’t a bird.

The Qesem teeth–in some respects–lack distinctive Neanderthal features. Perhaps they are human. Or perhaps they belong to some other hominin, like a Denisovan.

Here’s how the scientists end their paper:

There are three scenarios that might account for the morphological details in the Qesem teeth. The first one is of a local archaic Homo population occupying southwest Asia during the Middle Pleistocene, to which the Qesem specimens would be attributed. Perhaps relevant in this regard, the Qesem lithic assemblages studied to date indicate a local origin, with no evidence of African and or European cultural affinities (Barkai et al., 2005; Gopher et al., 2005; Barkai et al., 2009). Albeit the lack of other diagnostic Middle Pleistocene SW Asian teeth, considering the evidence in its entirety, we believe that the Qesem ‘‘package’’ is more Skhul/Qafzeh like, even if some of its features are plesiomorphous.

The second scenario is one of long-term in situ evolution of Neanderthals in southwest Asia. The presence of shoveling and a lingual tubercle in the stratigraphically younger maxillary teeth may be indicating the emergence of the Neanderthal morphological pattern during the Middle Pleistocene in southwest Asia. This would parallel the situation documented in Europe, where the Neanderthal evolutionary lineage has been shown to have roots extending deep into the Middle Pleistocene (Arsuaga et al., 1997; Stringer and Hublin, 1999; Bischoff et al., 2007). Under this scenario, southwest Asia would represent one regional subpopulation within the wider geographic range of the evolving Neanderthal lineage. Nonetheless, the large and well dated samples of fossil humans from Skhul/Qafzeh that post-date the Qesem specimens but predate most of the Neanderthal specimens from the region do not show an accentuation of Neanderthal features.

The third scenario is that more than one Pleistocene human taxon is represented within the Qesem dental sample. The mandibular teeth are stratigraphically deeper (older) but are smaller and lack plesiomorphous features identified in the chronologically later specimens. The differences between these chronologically disparate samples may reflect a population or species level distinction, and may involve population replacement on a local scale.

Resolution of these alternative scenarios must await further discoveries of additional and more complete Middle Pleistocene remains from southwest Asia. Nevertheless, the Qesem specimens represent an important contribution to the growing sample of Pleistocene human fossils from this circum-Mediterranean region of the Old World.

Nowhere in this conclusion do the authors say that these teeth belong to Homo sapiens. Nowhere do they say they have just doubled the age of our species. Nowhere do they say that our species evolved in the Near East, not in Africa. There are only some vague hints that the teeth might be “Skhul/Qafzeh-like.” Or they might be something else.

While the paper itself is non-commital in its conclusions, it contains lots of good detail about the teeth, which is why it probably got accepted at the American Journal of  Physical Anthropology. Who knows how some reporter got the idea that scientists had discovered the oldest fossils of Homo sapiens? It does seem that one of the authors has played footsie with reporters, offering some tasty quote-bait:

“It’s very exciting to come to this conclusion,” said archaeologist Avi Gopher, whose team examined the teeth with X-rays and CT scans and dated them according to the layers of earth where they were found.

He stressed that further research is needed to solidify the claim. If it does, he says, “this changes the whole picture of evolution.”

The logical thing a reporter should then do is ask, “How exciting can this conclusion be, when you never actually made it in the paper?”

The illogical thing to do is to declare that these teeth could “rewrite the evolutionary history of our species.”

[Image: AP Photo/Oded Balilty]

[Update: Brian Switek scoffs at Wired.]

[Update 12/31: Nature News interviewed Ari Gopher, the lead author on the paper, about the hype (and the take-downs from me and Switek). The article is particularly useful for finally tracking down the source of all these articles: a press release from Tel Aviv University that claims that "evidence was discovered pointing to the existence of modern man (Homo sapiens) in Israel as early as 400,000 years ago." (The press release was only in Hebrew, so I'm relying on Nature's translation.) Gopher claims that he told all the reporters who called him to be very cautious, but didn't think the press release was incorrect. "We offer the most reasonable conclusion based on the statistical evidence: that they represent the same population as the Skhul and Qafzeh finds, thus pushing the date for that type of early man back to a much earlier time."

Is it me, or is he talking about some other paper I haven't seen yet?]

A lot of people are interested in my Slate story yesterday on the arsenic aliens. It’s still the most-read story of the site at the moment, Slashdot and others have linked to it, and I’m doing some more radio and maybe other media (details to come).

I think that what has gotten so much attention to the story is just how many scientists had such critical things to say. The verdict was not unanimous, but the majority was large. I was only able to quote a tiny bit from just a few of the scientists I communicated with, so I thought, for those who’d like to delve more deeply into this, that I’d post a list of everyone I spoke to, and, when possible, post their reactions. A lot of scientists replied to me by email or even attached word files where they went on at length. I put together a similar dossier for another biological controversy–the search for soft tissue in dinosaur fossils–and I think (or at least hope) that this sort of exercise can help further discussion.

Of course, as I and others have reported, the authors of the new paper claim that all this is entirely inappropriate. They say this conversation should all be limited to peer-reviewed journals. I don’t agree. These were all on-the-record comments from experts who read the paper, which I solicited for a news article. So they’re legit in every sense of the word. Who knows–they might even help inform peer-reviewed science that comes out later on.

I’m going to post everything under the fold here, but it will take a little while. I’ll just re-save the post every time I add a new one, and I should be done before too long. So keep refreshing, or just drop by again later…

PS–Science has made the paper at the center of this controversy free. Get it here.

(more…)

Okay, if scientists won’t listen to me tell them they have to learn how to speak in plain English, maybe another scientist can drive the point home. From the intriguing blog The Plainspoken Scientist, via Colin Schultz.

I’m a judge again this year for the Imagine Science Film Festival, a fascinating Petri dish of short movies that feed on science and produce all sorts of interesting artistic metabolites. The festival has just kicked off, and there will be movies (both short and long) all week. Here’s the schedule. Having seen all the short pieces, I can say there’s some excellent stuff in the mix (although I won’t tell you exactly which ones I liked best till after the award ceremony on Friday).

Hearty congratulations to Ed Yong, fellow Discover blogger, for winning this year’s online National Academies Communication Award. I serve as a judge for the awards, so I told the NAS folks I would have to sit this particular vote out this year, seeing that a fellow member of the Discover hivemind was in the running. From the sidelines, I was very pleased to see him win. Ed’s torrent of well-researched blog posts on natural history give the lie (again) that blogging isn’t serious journalism.

Congratulations as well to Richard Holmes for his wonderful book, Age of Wonder, Charles Duhigg for his deep exploration of our water woes, and Carole and Richard Rifkind, co-producers and co-directors of the show, “Naturally Obsessed: The Making of a Scientist.”

Full details at NAS.

Over at the Atlantic, I describe my experience creating an ebook. First lesson: I don’t want to be the author of a Microsoft Word file. Check it out.

My deep thanks to Alexis Madrigal, the technology editor at the Atlantic, for inviting me to contribute my thoughts.

I’d like to introduce you to my latest book. It’s called Brain Cuttings: Fifteen Journeys Through The Mind. (Amazon / BN/ Mobipocket ) It’s my ninth book, but it’s my first dip into a new kind of publishing. And it was spurred on by you, dear reader.

Last year I put a survey on the Loom to find out about your reading habits—current and future. The 761 responses I got were surprising in a lot of ways, and they guided my thinking about what sort of new kinds of formats I could explore. I’ve been especially curious about how books can become blogified: in other words, writers can think up ideas for books, create them, and then quickly offer them up for sale at places like Amazon, regardless of whether they fit into the well-worn grooves of traditional publishing.

As a first foray, I decided to gather my favorite recent pieces on the brain. Some readers may have come across one or two of my published pieces over the past couple years, but I wanted to offer them a bunch of them—fifteen to be exact—in one place. Collections have always thrived on this convenience. If you’re a fan of Joseph Mitchell, for example, you could track down all of his pieces in individual issues of the New Yorker. Or you could just buy Up in the Old Hotel.

Ebooks are thriving on convenience too. You can read a lot of things for free online, but you need the patience to hunt for them amidst a lot of mediocre writing, pop-up ads, and text so poorly designed it burns out your visual cortex. Or you can tap the “buy” button on an e-reader and having a well-crafted book in seconds. The convenience sometimes borders on addiction. Finished The Thousand Autumns of Jacob Zoet? Well, David Mitchell’s previous book, Cloud Atlas awaits.

So I brought together fifteen of my favorite pieces. Fourteen of them are from Discover, and the final one is a long feature that I published in January in Playboy on the future of the brain—as seen through the funhouse prism that is a movement called the Singularity. I’ve edited them all, updating some of the science and giving them more of a unified feel of a book. Scott & Nix have given the book a lovely design and made sure it stays lovely in the various incarnations ebooks take these days.

I hope you’ll consider getting a copy, and passing on the word to anyone with a serious ebook addiction, or just a long flight to Phoenix to get through. Here’s the Kindle page, and Barnes and Noble’s. I’ve set up a page on my web site with more information. Other links are coming up in a fairly unpredictable way; I’ll update the book page as they arrive.

If you do get Brain Cuttings, please tell me what you think. This is still very much an experiment, and it’s not over. You can post a comment on this post or send me an email. (And if any bloggers, book reviewers, neuro-folk, or new media people would like a review copy, just get in touch.)

While working on Brain Cuttings, I’ve been thinking a lot about where science writing is headed, and I’ll be sharing some of my thoughts tonight at the Koshland Science Museum. Join us if you can (I think some seats are still left), or watch (and participate) through this livestream. I’ll also be thinking out loud in some future posts.

Let me leave you with some of the kind endorsements I’ve gotten for Brain Cuttings:

“Carl Zimmer takes us behind the scenes in our own heads. He has ferreted out all the most wondrous, bizarre stories and studies and served them up in this delicious, sizzling, easy-to-digest platter of neuro-goodness.” —Mary Roach, author of Packing for Mars and Stiff

“If you want to jump start your knowledge about how the brain does all those marvelous things for us like think, feel, and deal with others, read these essays. Zimmer has the rare capacity to get the science right and make it all feel like a glass of smooth bourbon.” —Michael Gazzaniga, Director for the SAGE Center for the Study of Mind at the University of California Santa Barbara, author of Human: The Science of What Makes Us Unique.

“These essays combine that rare blend of precision and wonder, hard-nosed reporting and nose for the poetically spooky. The brain should be very pleased to have Carl Zimmer as its scribe.” —Jad Abumrad, host and creator of Radiolab

“Carl Zimmer is one of the finest science writers around. In this fascinating tour of the brain, he explores the meaning of time, the genetic tug of war between parents, the science of anesthesia and a dozen other absorbing tales of the meaty computer inside our head.” —Jonah Lehrer, author of How We Decide and Proust Was a Neuroscientist

“Few writers are as clear and wide-ranging as Zimmer. In these fifteen day-trips into modern neuroscience, he clears away the fog of jargon to give us a clear view of the newly discovered land.”—David Eagleman, Baylor College of Medicine, author of Sum

Tomorrow I’ll be speaking in Washington DC at the Koshland Science Museum about communicating science in new media. It’s going to be a retro-future kind of talk. For one thing, I think Vesalius was a great model for thinking about science in new media. He had a lot of things figured out 450 years ago that we’re just rediscovering.

Plus the semi-super-secret project I mentioned last week. I’ll explain that tomorrow morning.

You can join me at the museum for free, but you have to make a reservation in advance by calling 202-334-1201 or emailing ksm@nas.edu. Or you can watch the livestream here, thanks to the folks at the American Society for Microbiology, which collaborates with the Koshland Museum. You can even ask questions via Twitter if you tweet them to @microbeworld or use the hashtag #koshland. We’ll be having a long Q & A session, and someone will be reading the questions from Twitter.

Here are the details:

Date: Thursday, October 14, 2010
Location: Koshland Science Museum
Time: 6:45 PM to 8:00 PM
6:45 – 7:15 Talk
7:15 – 8:00 Discussion

Museum Location: Located at the corner of 6th and E Streets, NW in downtown Washington, DC.

Next Thursday I’ll be speaking in Washington DC at the Koshland Science Museum about communicating science in new media. I’ll talk about some of the usual suspects–blogging, podcasts, the dreaded Twitter–but I’ve also got a new project to share. (I’ll blog the details about this semi-super-secret project in the next couple days.)

You can join me at the museum for free, but you have to make a reservation in advance by calling 202-334-1201 or emailing ksm@nas.edu. Or you can watch the livestream here, thanks to the folks at the American Society for Microbiology, which collaborates with the Koshland Museum. You can even ask questions via Twitter if you tweet them to @microbeworld or use the hashtag #koshland. We’ll be having a long Q & A session, and someone will be reading the questions from Twitter.

Here are the details:

Date: Thursday, October 14, 2010
Location: Koshland Science Museum
Time: 6:45 PM to 8:00 PM
6:45 – 7:15 Talk
7:15 – 8:00 Discussion

Museum Location: Located at the corner of 6th and E Streets, NW in downtown Washington, DC.

I’ve got several announcements to post over the next few days. Many eggs are beginning to hatch.

First up: New Yorker staff writer Michael Specter will be coming to New Haven to give a public talk on Monday, and then talk to my writing class Tuesday morning. Specter is the author of many important articles about science and medicine, some of which became the basis for his recent book, Denialism: How Irrational Thinking Hinders Scientific Progress, Harms the Planet, and Threatens Our Lives. You can find more about him on his web site and hear him talk briefly about denialism during his recent TED lecture.

Michael will be speaking on Monday, October 4 at 4 pm at Morse College at Yale (302 York St.). It’s a Master’s Tea, which means we’ll be gathering in a living-room-like setting, with real tea for those who want it. I organized a tea at Morse in the spring for Rebecca Skloot for her self-made book tour. Here’s an article about it, complete with a photo of the comfortable furniture.

(Thanks go to the Poynter Fellowship for making Specter’s trip possible!)

This is one of those meta stories that just won’t quit. Over the summer, scienceblogs.com lost a bunch of bloggers thanks to a certain bubbly beverage. A lot of the bloggers moved off to set up their own blogs elsewhere, which I tried to track in this post.

But then the bloggers began to coalesce. Order formed spontaneously from the chaos.

We saw some of them launch Scientopia

A couple settled down over at BigThink

The Guardian pinched a few for the new Guardian Science Blogs

Then the Public Library of Science started up a network too: PLoS blogs

Yesterday Wired pulled back their own curtain.

And now Scientific American has taken on the Thomas Paine of science blog networks, Bora!, who will help build up their own growing network of accomplished writers.

What’s particularly pleasing is that these networks are full of talented writers, and they clearly are getting great support–excellent layouts, bells, whistles, etc.

I would like to think these are all good signs that people out there are in fact hungry for science, and that an army of talented writers are going to enjoy unprecedented opportunities to meet that demand. But I’m something of a skeptic in all things, so let’s regroup in a year to see how everyone’s faring. For now–time to update the blogroll. Arg!

[Kudzu photo from Softcore Studios/Flickr]