Header image

john hawks weblog

paleoanthropology, genetics and evolution

Photo Credit: Okladnikov Cave. John Hawks CC-BY-NC-ND


A news story by Michael Price in Science: “Sleeping sickness hides in human skin”.

[Annette MacLeod] examined the samples for the sleeping sickness parasites and found them in a handful of people, even though they showed no symptoms of the disease at the time. Further testing revealed that mice with parasites in their skin, but undetectable levels of the parasite in their blood, can easily transmit the disease to tsetse flies. Taken together, these results indicate that human skin is likely an “unappreciated reservoir of infection,” MacLeod and colleagues report this week in eLife. People who display no symptoms and have virtually no parasites in their bloodstream can still carry the disease and transmit it to others if they’re bitten by tsetse flies, she says. Skin-to-skin transmission between humans is technically possible, she adds, but is likely rare because it would have to get into broken skin.
The upshot is that if health agencies only test people’s blood for African sleeping sickness—the most common practice—they’re going to miss remnants of the disease that prevent it from being completely eradicated. “These asymptomatic people are the secret reservoirs that keep the disease going,” MacLeod says.

This makes a lot of sense. A reservoir in asymptomatic individuals, with long-term possibility of infecting new hosts, is an essential for human pathogens of the Pleistocene.


Classic Phillip Tobias:

During embryonic, foetal and post-natal life, the form of the calvaria becomes accurately moulded over the surface of the expanding brain. Pulsating, as the brain does with the beating of the heart, the outer surface of the brain imprints itself upon the interior of the brain case. In some areas, the convolutions or gyri leave hollow impressiones gyrorum on the endocranial surface, separated by areas where endocranial ossification has penetrated, to varying degrees, into the sulci between the gyri. With care, one may be able to read off from the surface of an endocranial cast some of the markings that had originally bedizenned the surface of the brain.

Yes, he really wrote “bedizzened.” Unfortunately in a context too long to tweet!

Reference

Tobias, P. V. (1987). The brain of Homo habilis: A new level of organization in cerebral evolution. Journal of Human Evolution, 16(7-8), 741-761.

Link: The problem with 'basal' in phylogenetic trees

Stacey Smith summarizes the problems with using the term “basal” when discussing phylogenetic positions of organisms: “The ancestors are not among us”.

Basal is a term that refers to the position of a node near the root of a phylogenetic tree. It’s a perfectly good term, it just doesn’t describe the branches that come from that node. To understand why, I find the following paragraph makes the problem with “basal” especially clear:

Every branching in a (phylogenetic) tree is rotatable (see Fig. 1). Of course, the tree has a base, and there is a most basal branching and a next most basal branching, but there is no such thing as the most basal clade. Because branchings are rotatable, there are always two most basal clades (if the most basal branching is completely resolved, Fig. 1) or even more most basal clades (if the most basal branching is not completely resolved, e.g. in Polyneoptera in Fig. 1). Both branches originating from a node (i.e. the two sister groups) are of equal age and have undergone equivalent evolutionary change. Whether a group has branched off early (basal) or later in the phylogeny contains no information about this particular group, but information about both this group and its sister group, because both branched off at the same time.

That is from an editorial from 2004 by Frank Krell and Peter Cranston in the journal Systematic Entomology, “Which side of the tree is more basal? Smith points to the editorial in her post, and I found this discussion helpful.

I’ve thought a good amount about this issue as I’ve been working on an undated assemblage. Reading the literature in this light, I am amazed at how often anthropologists cover up uncertainty about the relationships within Homo with the term “early Homo”. I admit to being guilty of using this term myself, it seems like such a convenient way to forget about all the problems applying species concepts.

Reading these articles about “basal” reminded me that “basal” is no substitute. Phylogeny doesn’t give us an easy way to refer to these lineages from deep time, and that is probably for the best. It’s important to keep our trees straight.

References

Krell, F. T., & Cranston, P. S. (2004). Which side of the tree is more basal?. Systematic Entomology, 29(3), 279-281. doi:10.1111/j.0307-6970.2004.00262.x

Some thoughts on Dorothy Garrod and celebrity fossils

Lydia Pyne’s new book, Seven Skeletons: The Evolution of the World’s Most Famous Human Fossils is a reflection on how fossils become worldwide celebrities. I’m not entirely through the book but I like it quite a lot so far.

No one can write about the history of discoveries of these “famous” hominin specimens without taking note of the absence of women from the history of paleaonthropology. This week, Pyne published an essay reflecting on this gendered history: “Writing About Fossils Found By Men”.

Interestingly, women who show up in early paleoanthropology generally come from different background disciplines than do their male counterparts. Women tended to come to paleoanthropology from archaeology or anthropology, rather than from anatomy or paleontology – sciences that were less about spectacular discoveries of “things” (fossils) and more about understanding processes. But those sorts of research questions are hard to canonize in a science’s historical mythos. The discovery of some really cool fossil, traditional science storytelling goes, is so much more exciting to read and write about.
Accordingly, the traditional histories of paleoanthropology don’t have a whole lot of women in them. Dart’s student, Josephine Salmons, occasionally makes an appearance. Lady Smith Woodward shows up here and there in various stories of the Piltdown hoax, since her husband Sir Arthur Smith Woodward was so involved in Piltdown’s excavation and study. By and large, however, these women are ladies in the early fossil stories, not scientists. The big names in anthropological research, like Mary Leakey or Jacquetta Hawkes, tend to be researchers who focus more on the behaviors associated with early Homo than finding new hominin fossils. And this is pretty much the canon of paleoanthropology’s history of science as it currently stands.

As Pyne reflects on these famous fossils, she suggests that it is the “celebrity” nature of the fossils that tends to push women out of the story.

I found Pyne’s mention of Jacquetta Hawkes interesting in this context. Hawkes is not typically discussed in histories of paleoanthropology, because most of her work concerned the archaeology of the last few thousand years. In that area, she was a towering figure in the mid-twentieth century. But Hawkes herself did fieldwork as a student with Dorothy Garrod, and drew inspiration that set her on the path toward a career in archaeology (as discussed by the University of Bradford).

A skeleton of a Neanderthal woman was found, named Tabun 1 from the cave in which she was discovered. Jacquetta felt a strange kinship with this ancestral figure whose fragile skull she held. Despite their very different minds and experiences, both were part of the same stream of consciousness, “two atoms” in the millennial growth of the human brain.

Dorothy Garrod directed excavations that resulted in some of the epochal discoveries in the origin of modern humans and their interactions with the Neandertals. She didn’t make Pyne’s list because the Skhul and Tabun skeletal remains don’t fit her criteria of a single, “celebrity” skeleton. But that series of discoveries was much more important to the theoretical development of the field than most of the “celebrity” fossils.

If we consider the Skhul and Tabun discoveries, there’s no question that Garrod belongs in the pantheon of major fieldworkers in human origins. The Tabun archaeological sequence forms the basis for understanding the chronology of the Levant, with evidence for a quarter-million years of human habitation. To this we can add the excavation at Devil’s Tower, Gibraltar, and the Neandertal specimen it uncovered. Many archaeologists working today are frustrated with Garrod because her excavation methods left many unanswerable questions. Today no one would excavate a site like Tabun in the way that Garrod did. But this is true of almost every historical figure in the field.

Probably others would be more critical of Garrod than I am. I view her as one of the first prehistoric archaeologists to supervise massively interdisciplinary research. As she put it in her inaugural lecture as Disney Professor at Cambridge,

The prehistory of the Old Stone Age is far more closely bound up with certain branches of natural science—geology, palaeontology, palaeobotany—and the formation of a prehistorian in this sense calls for a scientific discipline to which the later stages of Man's story is not normally submitted.
It is noteworthy that among those who have built up the study of Early Man nearly all the outstanding names belong to men who have approached it from one or other of the natural sciences. This recruitment is to be expected in a subject which touches those sciences at so many points, and it has been of the highest value in the development and systematisation of human palaeontology in the widest sense. On the strictly archaeological side, however—that is, in the study of artefacts of fossil man—it has had certain results which are perhaps not quite so happy. It is time, I think, that these tendencies should be critically examined, and that we should ask ourselves whether they are not in part responsible for the present divorce between the student of the Old Stone Age and the archaeologist in the popular sense of the word.

With these words she introduced why archaeological knowledge is essential to understanding prehistory. Natural scientists, in her view, tended to treat artifacts as if they themselves were fossils, evolving under the laws of evolution, complete with hybridization and mutation. This in her view was wrong, leading to an exaggerated and typological view of cultural traditions. She was speaking to archaeologists about the importance of the archaeological approach.

As I read her, Garrod fully appreciated the role of different scientific disciplines in their own proper spheres, all of which had to be appreciated by the prehistorian. Certainly she followed that approach in her management of the excavation and study of material, in which she was strikingly modern in comparison to her scientific contemporaries. Like all modern discoveries of any importance, the Mount Carmel work in the 1920s and 1930s was a large-scale project that relied upon many collaborators. Theodore McCown, still a PhD student at the time, had responsibility for excavating the Skhul skeletons and transporting them to the U.K., where he worked to prepare them under the supervision of Arthur Keith. The resulting anatomical interpretation was one of the most important monographic descriptions of any fossil hominin sample, which faced up to the challenge of how to understand “transitional” patterns of anatomical features. It’s probably not an accident that Garrod, herself the daughter of a named professor of medicine, knew how to effectively work with experts in this area for this part of the work.

Thinking about McCown and Keith, they both influenced the interpretation of the fossils in such a way as to downplay their potential as “celebrity” fossils, notwithstanding Jacquetta Hawkes writing poems about the Tabun skeleton. Had Keith realized that the Skhul fossils were among were the earliest modern humans outside Africa, he might have created a mythos for Skhul V, but on this he missed the boat. Instead, he conceived them as transitional between earlier humans with more modern anatomy and later Neandertals. For his part, McCown refused to see the fossils as representatives a “type”, insisting that each was a mere sample of diversity within a population. The resulting description broke ground in how to conceive of variation in fossil human populations. Their science was a landmark, and the fossils did not take on mythological status in the process. I count that a scientific success.

I should point out that one consistent aspect of Garrod’s work is that her publications and reports all appeared “promptly” (as Jane Smith put it in a short biography). She was able to accomplish much, because she was effective in describing the science.

I don’t know how much Garrod’s approach to directing interdisciplinary work might have influenced Louis Leakey, who knew her. Looking at Leakey’s record it is clear that he conceived his and Mary’s roles differently than other earlier workers other than Garrod. The way that he recruited and delegated anatomical work to Phillip Tobias, John Napier, and other anatomical experts is reminiscent of how Garrod organized the Mount Carmel work. Maybe he would have taken this approach in any event.

At any rate, these are just a few of my thoughts. This seems like a fertile area for a historian to explore in more detail.


Michael Regnier has an article in Mosaic about the exceptional life and tragic end of George Price: “The man who gave himself away”.

I found it interesting that Mosaic commissioned the story in light of Oren Harman’s recent book about Price, The Price of Altruism, which is also an excellent account. But for a good short read, or for assigning in classes, Regnier’s article is a great one.

Châtelperronian bone fragments identified as Neandertal based on protein residues

Frido Welker and colleagues have applied a new method to identify tiny bone fragments as Neandertal remains, based on the protein residues that they contain.

The study uses a fairly simple concept—take a lot of unidentifiable bone fragments and test them with a protein mass spectrometry toolkit (ZooMS) to identify them to genus if possible. They were pretty successful. The real innovation is that they were able to identify a protein polymorphism for which 99% of living humans have a derived amino acid, and all known Neandertals have the ancestral amino acid. In the context of a Châtelperronian archaeological layer, finding the ancestral allele gives a strong indication (but not an infallible one) that a bone fragment probably has a Neandertal heritage.

I think the result is pretty cool because Welker and colleagues were able to identify a large number of bone fragments that probably belong to an infant skeleton, which they already knew was in the site based on a handful of identifiable remains.

Despite their spatial proximity within Layer X and squares C7 and C8, none of the newly described specimens could be fitted together to form larger fragments. The morphologically informative specimens, however, seem to represent small fragments of an immature cranium and an unfused vertebral hemiarch of neonatal age (SI Appendix, Fig. S10 and Table S13). This is supported by isotopic evidence suggesting that these fragments belonged to a nonweaned infant and by proteomic evidence in the form of proteins present in bone before bone remodeling has started. All the newly identified specimens were found in close spatial association with a previously described hominin temporal bone from square C7, Layer Xb, assigned to an infant around 1 y old, as well as 10 dental specimens from squares C7 and C8 (6, 7). These dental specimens overlap in developmental age, suggesting they represent one or possibly two individuals between 6 and 18 mo old (7). The 28 newly identified specimens, together with already described specimens, may therefore represent the skeletal remains of a single infant.

Châtelperronian makers

The reporting on this paper has emphasized the conclusion that the bones are Neandertal, which in addition to the protein evidence is also indicated by some mtDNA sequence fragments from some of the remains. To me this is basically a failure to reject a long-substantiated association: Neandertals made the Châtelperronian industry.

The Châtelperronian has been found across much of France and into the Pyrenées of Spain, and dates to around 40,000 years ago. It is termed a “transitional” industry because although it is based upon flaking strategies typical of earlier Mousterian assemblages, the Châtelperronian includes elements usually attributed to Upper Paleolithic toolkits including many bone artifacts and elongated flake tools that share many details with the blades of later Aurignacian assemblages.

The identity of the makers of the Châtelperronian has been a white whale for some archaeologists. The only diagnostic skeletal remains ever found with Châtelperronian tools have been Neandertals, notably the Saint-Césaire skeleton but also more fragmentary skeletal remains from Arcy-sur-Cure. Yet despite this association, some archaeologists have doubted that Neandertals made such apparently “sophisticated” tools. They have examined whether Châtelperronian assemblages are a palimpsest or mixture of elements from earlier Mousterian and later Upper Paleolithic contexts, whether Neandertal remains might have moved out of stratigraphic position, whether Châtelperronian layers may have slumped in a way not recognized in old excavations.

Today it would be truly surprising if an unambiguous modern human skeleton turned up in a Châtelperronian archaeological layer. If a specimen with modern human traits emerged, or a tooth that shared traits with modern humans, I would not be surprised, but that’s because I expect there was likely population mixture in Europe at the time of the Châtelperronian some 40,000 years ago.

Ten years ago, a debate erupted about the type locality of the Châtelperronian industry, Grotte des Fées du Châtelperron. I wrote about that episode here (Interstratified palimpsests), and it was never really satisfactorily resolved.

Why was it such a big deal? The last refuge of scoundrels has been the notion that Neandertals were incapable of making Châtelperronian artifacts on their own and needed the enculturating influence of modern humans to do so. This idea was popularized by Jared Diamond in his book, The Third Chimpanzee and has hung around within European archaeology for more than thirty years. The importance of possible interstratification of Châtelperronian and Aurignacian industries is a test that Neandertals who made Châtelperronian artifacts and modern humans who made Aurignacian artifacts might really have encountered each other on the same landscape. Without the possibility of such contact, it is hard to conceive of the idea that Neandertals were “acculturated” by their encounters with modern humans.

What is my opinion? I have to say, two or three thousand years is a lot of time, and it is hard for me to imagine that populations did not exchange a good amount of information across Europe during that time, whether they lived in overlapping areas or not. I doubt that the early Aurignacian people were very much different from late Neandertals in their cultural and technical abilities. Even if they were different on average for some cognitive abilities, which I can well imagine, I expect their abilities would have overlapped to a substantial degree.

The conclusion of the paper sums up my feelings fairly well.

Our biomolecular data provide evidence that hominins contemporaneous with the Châtelperronian layers have archaic nuclear and Neandertal mitochondrial ancestry, supporting previous morphological studies (6, 7). They are therefore among some of the latest Neandertals in western Eurasia, and possible candidates to be involved in gene flow from Neandertals into AMHs (or vice versa) (48). Future analysis of the nuclear genome of these or other Châtelperronian specimens might be able to provide further insights into the direction, extent, and age of gene flow between Late Pleistocene Western European Neandertals and “incoming” AMHs (49, 50).

More results coming

Doing more to uncover the hominin remains at a site is valuable even if the anatomical information to be gained is minimal, and even if genetic information cannot be reliably obtained from the fragments with today’s techniques.

Still, in the short term at many sites, what the method reveals about the fauna will be even more interesting. Identifying rare species in faunal assemblages from non-diagnostic fragments should greatly increase the representativeness of the archaeological record. As reported by Welker and colleagues in an earlier paper (2015), they can reliably identify bone fragments to genus in a large fraction of cases, even for bone fragments that have passed through a carnivore’s digestive tract.

This result is published this week just after a number of studies were presented in talks at an international conference on ancient biomolecules. That other work is reported by Ann Gibbons (“Oldest-ever proteins extracted from 3.8-million-year-old ostrich shells”), which includes a statement that protein has now been recovered from tooth enamel of extinct fauna from Dmanisi. Protein analysis of ancient fossils suddenly looks like a very big deal.

References

Brown, S., Higham, T., Slon, V., Pääbo, S., Meyer, M., Douka, K., ... & Derevianko, A. (2016). Identification of a new hominin bone from Denisova Cave, Siberia using collagen fingerprinting and mitochondrial DNA analysis. Scientific reports, 6. doi:10.1038/srep23559

Welker, F and others. 2016. Palaeoproteomic evidence identifies archaic hominins associated with the Châtelperronian at the Grotte du Renne. Proceedings of the National Academy of Sciences, U.S.A. (early edition). doi:10.1073/pnas.1605834113

Welker, F., Soressi, M., Rendu, W., Hublin, J. J., & Collins, M. (2015). Using ZooMS to identify fragmentary bone from the late Middle/Early Upper Palaeolithic sequence of Les Cottes, France. Journal of Archaeological Science, 54, 279-286. doi:10.1016/j.jas.2014.12.010

Some dissatisfaction with review articles

John Ioannidis often speaks out on abuses of confidence and statistics in science. He recently did an interview with Retraction Watch in which he commented upon the proliferation of “systematic reviews and meta-analyses” in science: “We have an epidemic of deeply flawed meta-analyses, says John Ioannidis”.

Retraction Watch: You say that the numbers of systematic reviews and meta-analyses have reached “epidemic proportions,” and that there is currently a “massive production of unnecessary, misleading, and conflicted systematic reviews and meta-analyses.” Indeed, you note the number of each has risen more than 2500% since 1991, often with more than 20 meta-analyses on the same topic. Why the massive increase, and why is it a problem?
John Ioannidis: The increase is a consequence of the higher prestige that systematic reviews and meta-analyses have acquired over the years, since they are (justifiably) considered to represent the highest level of evidence. Many scientists now want to do them, leading journals want to publish them, and sponsors and other conflicted stakeholders want to exploit them to promote their products, beliefs, and agendas. Systematic reviews and meta-analyses that are carefully done and that are done by players who do not have conflicts and pre-determined agendas are not a problem, quite the opposite. The problem is that most of them are not carefully done and/or are done with pre-determined agendas on what to find and report.

This comment resonated with me. This year has seen an explosion of review papers on hominin diversity.

The review papers that have appeared so far this year mostly seem to reflect symposium contributions that were presented in 2014 or 2015. Few of them have significant updates since they entered review sometime in 2015, and so they do not discuss findings of the last couple of years except very superficially. Most do not integrate findings from across different time intervals in human origins.

So, for example there have been three or four review papers this year summarizing hominin diversity in the Middle Pliocene. This is the time period that has produced evidence of Australopithecus afarensis, as well as a bunch of other species represented by a few fossils each, including A. bahrelghazali, Kenyanthropus platyops, and most recently A. deyiremeda.

Each of the review articles this year reads basically like a position paper by its authors about Australopithecus deyiremeda, either for or against.

This is a difficult area to review right now. The fossil evidence is sparse. Many of the authors consider the “best” evidence of species diversity to be the partial foot skeleton from Burtele, Ethiopia, which has not been assigned to a species. Few scientists have studied all the relevant material.

A real answer to the question of Middle Pliocene hominin diversity should start from a full and free examination of the variation found within the largest fossil samples, not excluding any specimens, and without any prior assumptions about their taxonomic status. We would need to revisit and test ideas from the 1980s about the taxonomy of Hadar fossils, relying upon the larger dataset that has since accumulated from Hadar and other sites. This would require us to seriously examine the idea that the cranial and dental fossils may represent more than a single species, and the postcranial fossils may represent more than a single adaptive pattern.

This kind of open examination would have many beneficial outcomes. Not least, it would provide some clear idea of what kind of evidence should be supplied to support the diagnosis of new species.

I recognize the root of my dissatisfaction in Ioannidis’ comments. The current crop of review articles, which serve the purposes of journals and players with pre-determined agendas, does little to advance the science. It is one thing when such a review is in a journal dedicated to review for non-specialists, like Annual Reviews in Anthropology or the Yearbook of Physical Anthropology. But it’s depressing to realize how little actual synthesis we are seeing in other contexts.


Good article in Undark about privacy and genome sequencing in the era of data sharing, by Adam Tanner: “The Promise and Perils of Sharing Your DNA”.

President Obama echoed this sentiment in February. “I would like to think that if somebody does a test on me or my genes, that that’s mine,” he said.
STILL, IT’S OFTEN HARD to know if you have signed away your ownership rights because of lengthy and obtuse privacy policies. “If you look at enough terms of service and privacy policies you will see the word ‘may’ or ‘might’ being used a lot — as in we ‘may share’ — which leaves the door open,” says Jan Charbonneau, a PhD candidate at the Centre for Law and Genetics at the University of Tasmania in Australia.

A nice piece in The Conversation by Edward Odes and Patrick Randolph-Quinney describing their research into the tumors afflicting ancient specimens from Swartkrans and Malapa: “Fossil evidence reveals that cancer in humans goes back 1.7 million years”.

Tumours and cancers are collectively known as neoplastic diseases. Until now, the oldest evidence of neoplasia in the hominin fossil record dated back 120,000 years. This was found in a rib fragment of a Neanderthal from Krapina in Croatia.
But our discovery, in two South African cave sites, offers definitive evidence of cancer in hominins – human ancestors – as far back as 1.7 million years ago.

Combating 'ivory tower' syndrome

There is much in this editorial by Andrew Hoffman that merits broadcasting more widely: “Why academics are losing relevance in society – and how to stop it”. I have been tweeting part of the article with a quote from University of Michigan President Mark Schlissel.

We forget the privilege it is to have lifelong security of employment at a spectacular university. And I don’t think we use it for its intended purpose. I think that faculty on average through the generations are becoming a bit careerist and staying inside our comfort zones. [But] If we’re perceived as being an ivory tower and talking to one another and being proud of our discoveries and our awards and our accomplishments and the letters after our name, I think in the long run the enterprise is going to suffer in society’s eyes, and our potential for impact will diminish. The willingness of society to support us will decrease.

In these comments, Schlissel encapsulated one perspective on the “ivory tower” problem. It’s hard to run a state university in today’s budget and political climate when many faculty appear to have little interest in serving the public. Within the U.S., state funding of universities is declining. They depend increasingly on federal research funding, which has remained steadier, but with an increasing proportion sucked up by overhead. Universities’ share of federal research funding has increased even as individual research grants become more difficult to obtain, but this cannot be sustainable in the long run. Particularly if the public interest in academic work is not sustained.

Many academics would respond that it is wrong to expect research to be useful or to have an impact on society. Or they might say that the topics of research are irrelevant to the purpose of the university, which is to advance learning and provide students with the tools to push the boundaries of knowledge.

But as it turns out, today’s students enter academic training hoping to make a difference in the world, not within a cloister:

Many graduate students report that they have chosen a research career precisely because they want to contribute to the real world: to offer their knowledge and expertise in order to make a difference. And many report that if academia doesn’t value engagement or worse discourages it, they will follow a different route, either toward schools that reward such behavior or leave academia for think tanks, NGOs, the government or other organizations that value practical relevance and impact.
The frustration is such that some no longer tell their advisors that they are involved in any form of public engagement, whether it be writing blogs or editorials, working with local communities or organizing training for their peers on public engagement. Will academia eventually spit these emergent scholars out, or will they remain and change academia? Many senior academics hope for the latter, fearing a worrying trend toward a reduction in the level of diversity and quality in the next generation of faculty.

These trends make me worry about the future. Students are clever and come into academic work with energy and goals to expand the importance of their fields. But so many established academic advisors actually diminish students’ abilities to reach out to the public.

Worse, the students who are successful at public engagement are often selected out of academia. What matters in tenure-track job competition is research funding, not engagement or broader impacts. Federal grants have included a “broader impacts” criterion for a long time. But in my experience reviewing grant applications, a negative assessment of a broader impacts plan has never resulted in a failure to fund the grant. I just do not see this criterion making any difference at all to the level of engagement expected for funding. As long as public engagement remains unimportant in the process of hiring, tenure, and grant funding, the students and early career academics who are most out of touch will continue to win positions and prestige, and students who succeed at engagement and public impact will continue to seek other opportunities.


Interesting approach to getting students to collaborate in a course, from Adam Grant:

The most difficult section of my final exam was multiple choice. I told the students that they could pick the one question about which they were most unsure, and write down the name of a classmate who might know the answer — the equivalent of a lifeline on the game show “Who Wants to Be a Millionaire?” If the classmate got it right, they would both earn the points.
Essentially, I was trying to build a collaborative culture with a reward system where one person’s success benefited someone else. It was a small offering — two points on a 120-point exam — but it made a big difference. More students started studying together in small groups, then the groups started pooling their knowledge.

Nice article by Natalie Angier about recent work on bonobo social behavior: “Beware the Bonds of Female Bonobos”.

The latest research indicates that the nature of the bonobos’ sororal bonds shifts depending on circumstances, and that the most effective deterrent to male harassment may be a cross-generational pact.
“I sometimes think that bonobos sit up late at night reading papers about primates, and then decide to do the opposite,” said Joan Silk, a primatologist at Arizona State University. “They’re unusual in so many ways.”

This is awesome:

The problem of drug-resistant infections is terrifying but also abstract; by their nature, microbes are invisible to the naked eye, and the process by which they defy our drugs is even harder to visualise.
But now you can: just watch that video again. You’re seeing evolution in action. You’re watching living things facing down new challenges, dying, competing, thriving, invading, and adapting—all in a two-minute movie.

An experimental setup in which bacteria colonize progressively more antibiotic-laced environments when they have favorable mutations, all put on video.


Oliver Morton thought that the recent Proxima Centauri exoplanet news would be bigger; he ponders why he was wrong: “It will be a long time before you see another exoplanet on a front page”.

Various people suggested to me on twitter that the public has become a little blase about exoplanets, possibly because they have been a bit oversold. (One person suggested that astronomers may have cried wolf too often, which I mention mainly in order to link to this bit of brilliance from Mitchell and Webb). With regular announcements of planets more “earthlike” than the last — but with no evidence that any of them is actually remotely like the Earth — the fact that this one was nearer than any of the others hardly seemed like that big of a step forward.

It is a real challenge in the public communication of science to explain the interesting parts of incremental progress.

Sequencing new animal genomes is no longer newsworthy absent some additional and surprising scientific finding from them. Technology has progressed and new data are coming in, but each incremental data point is not advancing theory.

When the buildup of data starts leading to new scientific predictions and insights, that will make much more of an impact.


This is a fascinating story of the age of massive databases and loss of human privacy: “How an internet mapping glitch turned a random Kansas farm into a digital hell”.

For the last decade, Taylor and her renters have been visited by all kinds of mysterious trouble. They’ve been accused of being identity thieves, spammers, scammers and fraudsters. They’ve gotten visited by FBI agents, federal marshals, IRS collectors, ambulances searching for suicidal veterans, and police officers searching for runaway children. They’ve found people scrounging around in their barn. The renters have been doxxed, their names and addresses posted on the internet by vigilantes. Once, someone left a broken toilet in the driveway as a strange, indefinite threat.
All in all, the residents of the Taylor property have been treated like criminals for a decade. And until I called them this week, they had no idea why.