Holiday Readings: Ancient Amputations, First Americans, Fossil Molluscs

Wishing my readers a very Happy New Year! I hope these readings will be to your liking.

1) Can ancient amputations tell us about the care systems of our ancestors? Paleoanthropologist John Hawks surveys the fossil record of ancient humans for signs of severed limbs due to trauma or disease. He also presents cases of limb loss in other primates and offers a perspective on what all this can tell us about past social systems. 

"Both humans and nonhuman primates show us that survival and life after extreme injuries happen under varied circumstances. Bioarchaeologists tend to highlight severe injuries, which stand out from the more subtle patterns of osteological signs of disease that can be understood only across large samples of skeletons. But such individual stories rarely yield unambiguous interpretations".

2) Finding the First Americans. Anthropologist Jennifer Raff brings together often conflicting genetic and archaeological data on this ever vexing and complicated question of how the Americas were populated. 

3) Finding Molluscs. This podcast (with transcript) is part of an excellent continuing series of earth science and paleontology podcasts by Mongabay India. In this episode, host Sahana Ghosh talks with paleoecologist Devapriya Chattopadhyay on her research on fossil molluscs. Dr. Chattopadhyay uses these creatures to track ancient environmental conditions and ecology. She also speaks on the urgent need for India to create a national fossil repository and museum which will help preserve our deep history for future generations.

Chimpanzees Cooking

What do you have to say to this statement by psychologist Felix Warneken ?

“The logic is that if we see something in chimpanzees’ behavior, our common ancestor may have possessed these traits as well. If our closest evolutionary relative possesses these skills, it suggests that once early humans were able to use and control fire they could also use it for cooking.”

I would say that one has to be very careful in drawing general implications about ancestral abilities from the behavior of chimpanzees. They are not some frozen Pliocene ape. The human-chimpanzee split from our common ancestor may have occurred 7-8 million years ago. Since divergence,  the lineage that led to chimpanzees has been evolving for the same amount of time as our lineage. Many aspects of modern chimpanzee behavior may not reflect the ancestral condition but instead may have evolved later in their evolutionary history.

What the study that is described in the Guardian shows is that chimpanzees prefer cooked food to raw food and have abilities to defer instant gratification for later preferred reward. This though need not be restricted to cooked food. You could conceivably show that they for example behave the same way if given a choice between a raw and a ripe fruit. Or for that matter something not to do with food at all. There is no evidence that chimpanzees throw raw meat in natural forest fires and come back and eat the cooked meat. Awaiting for cooked food does not mean they posses "most of the intellectual abilities required for cooking"

And nor did our very early human ancestors. One implication drawn from these chimpanzee "cooking" experiments is that our ancestors may have developed a taste for grilled meats early on (possible) and the timeline for cooking may have to be shifted to an earlier date. I don't see the latter connection at all. The oldest confirmed evidence for cooking is about 1 million years ago, although some scientists like Richard Wrangham based on changes in physiology (larger brain, smaller molars)  seen in the fossil record push it back to around 2 million years ago.  Even assuming that the chimpanzees preference for cooked food reflects the ancestral state, one can't draw a connection between that and cooking appearing earlier in our lineage. It took 4-5 million years after our lineage split from the chimpanzee for us to evolve the ability to control fire and the addition of deliberately cooked food as part of our regular diets. That is hardly "early". It took a long time, in fact cooking has been absent for most of the time of our lineages existence, and it was contingent on a host of other unique changes in our cognition, social evolution and our abilities to use our limbs to manipulate objects.

There was nothing inevitable about it.. one just has to look at the chimpanzees. In fact, this precaution taken during the experiments gives the game away-

“Originally we thought of setting up a camping cooker in their sleeping area, but you could imagine them getting hold of a gas tank or burning themselves,” said Warneken. “This was not a viable option.”

It was not a viable option because chimpanzees don't even come close to possessing most of the required abilities to cook.

That is one of the problems of drawing sweeping evolutionary implications about behavior from contrived experimental situations.  They just don't bear any resemblance to behavior in the natural state.

Existential Awareness In Gorillas

We always knew that great apes were smart and thoughtful creatures, but they continue to surprise in terms of just how human-like they really are. Using some innovative techniques like euthanizing a pet cat and other visual cues, researchers from Tulane University Louisiana have recently taught Quigley a western lowland Gorilla that he - just like every other living creature - will die one day. Quigley, after a few initial panic attacks soon came to terms with his own mortality. 

A report from the reliable Onion.


 
via WEIT

Violence Part Of The Social Experience In Indus Civilization

Researchers Gwen Robbins Schug and Veena Mushrif Tripathy in an interview with Anthropology news have this to say about Harappan society:

It was argued that Harappa was a rare example of a peaceful, heterarchical state. The human skeletal material was never consulted to address this question. Based on our evidence for both exclusion and social differentiation in the mortuary practices at Harappa, we argue that Harappa was not entirely peaceful and social differentiation was part of life. We hope archaeologists working in this area will plan future excavations to include the peripheral areas outside the cities; excavation outside the city walls will tell us more about Indus society.

We are using the human skeletons as artifacts of the social experience. We used the concept of structural violence in our most recent work because it accounts for the clear distinctions we see in the burial practices, ritual aspects, prevalence of trauma and infection. The mortuary and bioarchaeological evidence at Harappa suggests that the social experience in South Asia was not exceptionally different from other early urban civilizations; the kinds of suffering and the patterns of violence present at Harappa suggests structural violence—unequal power, uneven access to resources, and oppression that leads to denial of basic needs and even violence.

Lest some people get too excited about the use of the words Harappa and violence in the same sentence, let it be made clear that this violence refers to interpersonal violence present in any complex society and not violence inflicted by outsiders during war.
 

Spreading Altruism By Jumping On A Live Grenade

On the comments thread of Why Evolution Is True, Prof. Jerry Coyne uses a fun example to explain the concept of inclusive fitness to a reader:

josh ozersky-
Can someone please explain what inclusive fitness is?

whyevolutionistrue-

Basically, it’s calculated for a gene that does something like affect behavior, and it’s the relative fitness of that form of a gene compared to other forms that don’t have that behavior, counting the copies of that gene in related individuals. For example, a gene that codes for this behavior: “commit suicide (e.g. by falling on a grenade) if you can save more than two brothers or sisters by doing so” has a higher inclusive fitness than a gene that says “don’t fall on the grenade”, because if you die you lose one copy of that gene but save 1.5 others (you’re 50% related to those three siblings), while if you don’t fall on the grenade (and run away), you save your own copy but lose 1.5 others. The gene for the “altruisitc” behavior will spread because genes for it have a higher INCLUSIVE FITNESS than the other form of the gene.

Is that clear?

The discussion is with reference to Prof. Coyne's post on E.O. Wilson's book Sociobiology and his recent profile by Jenny Schuessler in the New York Times. 

Psycho-Shrinking The Neanderthals

On Quirks & Quarks host Bob McDonald and psychologist Prof. Frederick Coolidge have an entertaining discussion on Neanderthal behavior.

Apparently, the fossil record suggests that the Neanderthals recovered from injuries sustained above the waist. Injuries to the foot though were generally fatal. Prof.  Frederick Coolidge suggested that while Neanderthals took care of their injured, a foot injury meant that that individual couldn't take part in a hunt and move around with the band and may have been left behind to die.

I don't get this. If empathy was extended to individuals who were injured above the waist and presumably couldn't be useful in a hunt in that state and possibly had to be helped move from place to place, why would that empathy stop below the waist?

Here is one for keeps. Frederick Coolidge agrees with Bob McDonald that the Neanderthals would have had a sense of humor, but a slapstick kind of a humor. More like the Three Stooges. They would be lost on puns and word play.

I wonder if Prof. John Hawks considers this damaging enough to be placed in his Neanderthal anti-defamation files!

Male Australopithecines Were Not House Husbands

Evolution research is routinely misreported in the Indian media and I had a chuckle when I read this summary published in the Times of India:

Early women worked, men stayed home:

Early species of cavemen who roamed the earth two million years ago did not go to work but stayed at home and looked after the kids, while their females earned bread for the family, says a new research.

Scientists at the University of Oxford arrived at the conclusion by using new techniques to extract information from the fossilized teeth of our ancient human ancestors.  

No..no...  the conclusion scientists reached after studying strontium isotope content of fossilized teeth from two species of ancient hominins from South Africa was not about the daily division of labor between the sexes but about another aspect of their social life.

Different rock types like granites, basalts, dolomites have characteristic strontium isotope signatures. Plants take up strontium from bedrock and derived soil. Animals eat those plants and the strontium ends up in the enamel of their teeth. Analyzing the strontium isotope values of ancient mineralized teeth can help identify the geological substrate on which ancient animals, in this case ancient hominins lived. 

Scientists tested 19 teeth from the Sterkfontein and Swartkrans cave sites in South Africa dating from about 2.4 to 1.7 million years ago from two hominin species, Australopithecus africanus and Paranthropus robustus. These samples were preserved in a dolomite substrate.

The fragmentary body fossil record of these two species hints at a considerable degree of sexual dimorphism i.e. the females were significantly smaller in size than the males. When the the teeth were analyzed scientists found that a large proportion of smaller teeth likely belonging to females show strontium isotope values not reflecting the local landscape i.e. not reflecting the dolomite substrate, suggesting that many females had come into this area from outside the geological terrain where these sampled populations lived. On the other hand,  a large proportion of teeth likely belonging to males reflected local geology.

So, the inferences drawn from the strontium isotope values were (a) in these ancient hominins, females on reaching maturity dispersed away from their natal or family group and joined another group while males remained with their group and did not migrate elsewhere, and (b) male hominins had small home ranges i.e. they stayed most of their lives in a relatively small area.

Many social animals show a pattern of either the females or males leaving their family group on maturity, a behavior that may have evolved to minimize inbreeding. The social pattern of female dispersal inferred in these ancient hominins is similar to that seen in chimpanzees and many modern human societies as well.

Social behavior does not fossilize. Tools made by ancient humans is one way to understand certain aspects of behavior. In this case the scientists linked a physiological mechanism - the uptake through food and localization of strontium in teeth - to social behavior.

I thought it is a smart piece of forensic science.. even though it didn't tell us whether or not those ancient males were house husbands!

Science Daily summary.

Is My Fossil Not Spongeworthy?

The Australian reports on a recent announcement of possible sponge-grade metazoan remains from the Flinders range in south Australia claimed by a research group from Princeton University and hints at a darker controversy involving priority:

Paleontologists such as Jim Gehling with the South Australian Museum say it is no surprise that simple sponge-like animals lived 600-650 million years ago, as reported yesterday in the journal Nature Geoscience. But they are far from convinced they are what the Princeton University team has found.

"To argue these were sponges is a difficult proposition. They look like Coco Pops, " said Dr Gehling.

Moreover, Dr Gehling said better, older fossils had been found three years ago by University of Melbourne geologist Malcolm Wallace and his team. Dr Gehling suggested that competitive pressure might have been the reason Dr Wallace's group has been unable to publish their results.

The Australian understands that one of the co-authors of the contentious paper is a reviewer for the journal Science, to which Dr Wallace's group has submitted a paper. It is not clear whether the reviewer has read the paper but Dr Wallace acknowledged that "we've had difficulties getting our results published". He preferred not to discuss Dr Gehling's suspicions. He did affirm that his group's finds were roughly 20 million years older than those reported by the Princeton team, headed by paleontologist Adam Maloof.

Using a position of influence to suppress a rival groups study from being published would be a very serious ethical transgression but if the identity of the reviewer is that obvious would anyone take that risk?

Andrew Alden at Geology.about.com and Chris at Highly Allochthonous express their opinions about the study.

Preparing For The Next Big Oil Spill

David Brooks writes a perceptive column in NY Times in which he argues that preparation for the next big disaster has to include not just better technical and mechanical processes but improvements in understanding human psychology which is not very good at complicated risk assessment:

So it seems important, in the months ahead, to not only focus on mechanical ways to make drilling safer, but also more broadly on helping people deal with potentially catastrophic complexity. There must be ways to improve the choice architecture — to help people guard against risk creep, false security, groupthink, the good-news bias and all the rest. 

This isn’t just about oil. It’s a challenge for people living in an imponderably complex technical society.

He quotes Malcolm Gladwell a lot.... synthesizer of stories on how seemingly disparate small events can link up and cascade into a really big event.

Israel -Jordan Border: Rodents Too Behave Differently

This from a Science Daily press release on the differences in ecosystems and animal behavior across the Israeli Jordanian border :

....the differences between Israel and Jordan are primarily in the higher level of agriculture and the higher number of agricultural farms in Israel as opposed to Jordan's agriculture that is primarily based on nomadic shepherding and traditional farming. The agricultural fields on the Israeli side of the border not only create a gulf between habitats and thereby cause an increase in the number of species in the region, but they also hail one of the most problematic of intruders in the world: the red fox. On the Jordanian side, the red fox is far less common, so that Jordanian gerbils can allow themselves to be more carefree. The higher reproduction rate of ant lions on Israel's side is also related to the presence of another animal: the Dorcas gazelle. This gazelle serves as an "environmental engineer" of a sort, as it breaks the earth's dry surface and enables ant lions to dig their funnels. The Dorcas gazelle is a protected animal in Israel, while hunting it in Jordan is permitted and compromises the presence of the Jordanian ant lions' soil engineers.

Important lessons for conservation here.

Allocyclicity vs Autocyclicity: An Old Debate Revisited

An old debate on sedimentary cycles and research topic choices came to mind.

Brian at Clastic Detritus has an informative post with some great images on the discovery of rhythmic sediments deposited on Mars. As the name implies rhythmic sediments are not just layered but a particular type of sediment has been deposited at a regular frequency throughout that geological section.

The origin of these rhythms is a widely researched area of stratigraphy and sedimentology. As Brian explained these rhythms or sedimentary cycles can be allocyclic in origin or autocyclic in origin. Allocyclic means that periodic changes in an external factor such as cyclic climatic changes forces the environments of deposition to change in a cyclic manner producing a cyclic sedimentary record. Autocylic means that the sedimentary processes within a sedimentary basin develop cyclic feedback loops linking sediment production, transportation and deposition. This results in similar environments of deposition appearing at and disappearing from any particular location within the basin at periodic intervals leading to a cyclic sedimentary record.

Preliminary work suggests that the Mars rhythmic sediments are likely allocylic in origin, maybe linked to cyclic climatic changes on Mars. Brian thinks they are chemical deposits formed in a large lake. Maybe; it will be fun following this research.

Coming back to planet Earth this debate on allocyclicity vs autocyclicity in carbonate strata was being played out in a big way during my graduate students days in the early-mid 90's. The focus of study was the Cambro-Ordovician passive margin platform carbonates of the central and southern Appalachians. Two big labs, one based in Virginia and the other in Tennessee developed quite opposing points of view.

At Virginia Polytechnic, J.F. Read headed the carbonate research group and championed the allocyclic model. All his students who worked on stratigraphy related projects found strong evidence of allocyclicity in the sequences they studied. Further south, Kenneth Walker of the University of Tennessee at Knoxville downplayed allocyclicity as a viable model for shallow platform carbonates and stressed internal feedback loops and autocyclicity as a better explanation for the observed facies changes. All his students found strong components of autocyclicity in the sequences they studied.

Mind you, the students from the two different labs were working on carbonate sequences from the same time period deposited in adjacent areas of the same tectono-sedimentary setting.

Even further south I worked on the Alabama and Georgia Appalachian carbonates for my thesis at Florida State Univ. I took the smart option. I avoided the debate altogether and worked on the geochemistry of cements.

But I did follow with interest the work of my colleagues up north. Both these founders of the two large research labs are influential charismatic personalities. I don't doubt that new eager graduate students imbibed a particular way of thinking about carbonate deposition by listening to their mentors. But why such a clear divide in research results?

I am in no way suggesting that students made up results to fit preconceived notions. Could it be that students were genuinely interpreting the same sequences differently because of a mental bias or simply due to an unclear understanding of the characteristics of these two different cycle modes. This may have happened in the very early days of the history of these research programs. But over the years stratigraphers have developed some pretty discriminating models of the two types of cycles. As the two research labs developed a more sophisticated understanding of the topic I suspect a more subtle bias developed.

Carbonate platforms vary in their water depth. There are really shallow areas, let's say just about knee deep water and there are areas which are few to several meters deep. It is in these slightly deeper water areas that signals of allocyclicity or external forcing are best preserved. Very shallow water areas, those in the intertidal and supratidal zone for example are more readily affected by internally produced disturbances and feedbacks in sediment deposition and production. These are areas where signals from externally forced cyclicity get swamped by locally produced cyclicity.

I didn't follow each and every thesis produced by these students, but what I am speculating is that students of Virginia Tech, started choosing as research topics slightly deeper water sequences which best made the case for allocyclicity, while students of Tennessee started choosing those environments of deposition where autocyclicity was the dominant process. The results they got may have been genuine but they were in a sense inevitable given their choice of a particular type of study material. I may be completely wrong but this is something you could test by a detailed literature review to see if there was a preference within the two labs for selecting particular environments of deposition to study.

Moving away from these carbonates to a more broader theme. How much does an influential mentor dictate the choice of your research project? I would be interested in hearing from other geobloggers. Did you have an experience of working in a large research lab with a larger than life research head, where a particular school of thought had been established and which influenced your work? Were you really critical of this established way of thinking or did you just accept it and use it as a foundation for your work?

Is it better then to choose to go to a smaller lab which might not have developed a tradition of thinking in any particular direction? And finally doesn't the influential mentor have a responsibility to develop internal differing points of view? How about assigning a couple of students on projects that might potentially disprove the established tradition?

Camera Tricks on Absent Teachers

From Tim Harford's Column in the Financial Times

Esther Duflo, a French economics professor at MIT, wondered whether there was anything that could be done about absentee teachers in rural India, which is a large problem for remote schoolhouses with a single teacher. Duflo and her colleague Rema Hanna took a sample of 120 schools in Rajasthan, chose 60 at random, and sent cameras to teachers in the chosen schools. The cameras had tamper-proof date and time stamps, and the teachers were asked to get a pupil to photograph the teacher with the class at the beginning and the end of each school day.

It was a simple idea, and it worked. Teacher absenteeism plummeted, as measured by random audits, and the class test scores improved markedly.

According to UNICEF India, there is a correlation between teacher absenteeism and simply the daily incentives to appear to work. Better teacher attendances are seen in schools closer to paved roads, schools that are inspected regularly and have better infrastructure. Absenteeism in general increases in low-income states. Obviously can't distribute camera's to ten's of thousands of schools across the country. Any ideas on how to improve teacher absenteeism without resorting to tricks like this? Another thought. Maybe if 60 schools that did not get the camera knew such a system is keeping tabs on teachers, would that have acted as an incentive to show up to school so as not to appear worse off in comparison with the schools with the camera? This was a small scale approach in influencing behavior through monitoring, but it does show that holding individuals accountable through some type of monitoring system- something that is never strongly enforced in India - would act as a pretty strong incentive to modify behavior.

Bottoms Up to Prevent Climate Change

The Times of India science reporter Narayani Ganesh has this prescription for combating climate change:

What if we shifted the entire responsibility on to the shoulders of one well-known person, say someone like R K Pachauri, who heads The Energy Research Institute and the Nobel prize-wining Intergovernmental Panel on Climate Change? He could institute a climate hotline, a blog, office, radio talk-in show, agony uncle column or any other kind of public interface system that would encourage people to respond to, complain of, discuss, give ideas, share experiences and counsel/get counselled on anything related to saving the planet and ourselves from the scourge of global warming. Collection boxes - on the lines of those displayed by organisations like the Red Cross, CRY or PETA - placed at strategic points and monitored carefully could help assuage the guilt of individuals while galvanising fund-raising on a fairly large scale.

Ganesh is frustrated with the government's response to climate change and wants a bottoms up approach whereby eminent scientists will raise awareness by writing columns and funds for research in alternative energy are raised by placing collection boxes. Will this strategy work? I can imagine people responding to columns with plenty of suggestions and advice but will something like this change habits and behavior and genuinely lead to reduction in emissions? Recently the British rock band Radiohead allowed online downloads of their latest album on a voluntary payment basis. Fans could pay as little or as much as they wanted. Nearly two thirds payed nothing and the rest on average less than $3 for an album that cost about $16. If offered a free lunch people grab it with both hands. Radiohead's collection box remained nearly empty. Free lunches abound in India. The government doles out free electricity, subsidizes fuel, water, gas and roads and most people make full use of this largesse and seem not to be racked with guilt. Urban India is consumed by consumerism and a rural population is aspiring for that. We Indians have grown so used to these government handouts that columns and blogs by an over-hyped UN administrator and a few collection boxes are likely to be ignored.

A bottom's up approach, people's participation in minimizing climate change have a feel good quality to it. People appear altruistic and can feel less guilty without actually bearing any significant costs, which is why politicians will likely support such schemes. On the other hand, schemes that will make a real difference in reducing emissions, such as fitting carbon scrubbers to coal plants, charging more for electricity, tolling roads, introducing congestion charges for vehicles in urban centers are highly unpopular and unlikely to be introduced at least for some time. So, India will go through a strange phase whereby politicians will actively encourage useless schemes like scientists writing columns and collection boxes to raise funds for "research", while distancing themselves from regulations that impose limits on emissions. Our emissions and accompanying pollution will keep growing. Unless there is a political will to take tough decisions, a top-down imposition, the 3 Indians out of a 1000 with Internet connections, will have to make do reading Mr. Pachauri's blog on preventing climate change. Bottom's Up for that! :-)

Clever Parrot.......Dead

Alex, an African grey parrot and one of the most celebrated scientific subjects died of natural causes a few days ago. He was 31 and spent most of his life working with Dr. Irene Pepperberg, a comparative psychologist at Brandeis University and Harvard. Alex became famous for his cognitive abilities. He knew more than 100 English words, could tell between different colors and shapes and occasionally came up with unique one-liners which would amaze people not familiar with success rates of animals trying to "speak". Alex's considerable abilities, along with other examples of studies of birds, are making us aware that birds are not ...well....bird-brained.

For example some recent studies on Caledonian crows have revealed complex tool manipulation abilities in those crows. These birds show the ability to use one tool to manipulate another tool to achieve a particular task. In one study, food was stored in a hole out of reach of an easily available, but short stick. A long stick which could reach the food was kept some distance away in a toolbox. The crows quickly learnt to use the short stick to fish out the long stick from the box and then use the long stick to get at the food in the hole. In a variation of this study, researchers reversed the position of the sticks. The crows again quickly modified their behavior and directly used the long stick to get at the food.

In another interesting piece of research on scrub jay's, researchers noticed that scrub jay's bury their food from rivals and then surprisingly some scrub jay's sneak back and re-bury their food when their rivals are not present. This was seemingly being done to avoid pilfering by other birds. The shock came when controlled experiments revealed that only those scrub jays who themselves had previously stolen other scrub jay's food came back to relocate their food resources. Jay's with no previous experience of thieving did not bother re-burying their food. All this suggests that these birds have some sort of a ' theory of mind' i.e. the ability to use one's own experience to mentally time-travel and anticipate the actions of another and then use that information for manipulative purposes. This ability to sense that other individuals have thoughts and desires similar to yours was thought to be restricted only to humans, but evolution seems to have given rise to analogous abilities in some species of birds as well.

Alex's passing has generated a fair bit of press. Eulogies have ranged from the decent and serious as in this NYtimes report, to the light-hearted as in this blog. This leaves some space for dark comedy, an opportunity I don't want to miss. So in the words of Monty Python's enraged customer who tries to convince the pet-store owner that the parrot he bought from him an hour ago is really dead, a somewhat macabre goodbye to Alex:

''E's passed on! This parrot is no more! He has ceased to be! 'E's expired and gone to meet 'is maker! This is a late parrot. 'E's a stiff! Bereft of life, 'e rests in peace! If you hadn't nailed 'ime'd be pushing up the daisies! 'Is metabolic processes are now 'istory! 'E's off the twig! ' E's kicked the bucket, 'e's shuffled off 'is mortal coil, run down the curtain and joined the bleedin' choir invisibile!! This is an ex-parrot.

Adieu Alex!