Ridley discusses relaxed selection by bringing up an IVF technique, intracytoplasmic sperm injection, used help men with immotile sperm to father children. Firstly, since he didn’t mention the cause of immobility of the sperm, I must mention that in any given man a significant portion of sperm are immotile. The ratio of immobile sperm to motile sperm is critical, as is the volume of or sperm count. The WHO standard for motility of sperm is about 50% of the sample, any less than the risk of infertility rises. However, if the sperm count is high, then having less than 50% motility is not an issue.

There are certain circumstances where almost all sperm are immobile, such as Kartagener’s syndrome. Kartagener’s syndrome is a primary ciliary dyskenesia. This is an autosomal recessive genetic disruption in the arms of the motor protein dynein. Kartagener’s syndrome is approximated to be present in 1 out of 15,000 – 32,000 men., of which infertility is not a primary concern. I write this because main result of impaired ciliary function is the impairment of clearing mucous to the lungs. Chronic respiratory infections due to progressive damage to the respiratory system, leads severe diseases like bronchiectasis beginning in early childhood. Prevention of these complications is more important than using IVF.

Ridley weakened his argument on relaxed selection, because he failed to discuss the details of what sperm immobility is and means. Furthermore, in an example of true spermatic immobility, surviving to reproductive age when respiratory complications hit is low. Why didn’t he address the relaxation on selection with the increase use of C-sections?

In the next half of the article, I can’t tell if Ridley was playing Devil’s advocate with this excerpt,

“Now, thanks to pre-implantation genetic diagnosis, parents can deliberately choose to implant embryos that lack certain deleterious mutations carried in their families, with the result that genes for Tay-Sachs, Huntington’s and other diseases are retreating in frequency. The old and overblown worry of the early eugenicists—that “bad” mutations were progressively accumulating in the species—is beginning to be addressed not by stopping people from breeding, but by allowing them to breed, safe in the knowledge that they won’t pass on painful conditions.”

Parents are still giving birth to children with known and unknown deleterious mutations. Post-implantation diagnosis of genetic diseases with techniques like such as amniocentesis or chorionic villus sampling are not offered to all expecting mothers, nor do all expecting mothers chose to these tests… Let alone pre-implantation! To say that these this practically non-existent option has directly caused a decrease deleterious traits to no longer be selected against is a bold and brash statement. The increase in admixture is a more impactful variable in the reduction of incidence in genetic diseases the pre-implantation diagnosis.

Ridley also brings up the differences of SNPs seen between people of European and African ancestry, attributing nothing of substance to the observation that Europeans have half as many SNPs as Africans. He implies, “larger population allow more variants [with] less severe selection against mildly disadvantageous genes,” and attributes the expansion of population in the last 5,000 years to this. But within a species, mutation rates are constant, regardless of the selective pressure.

Lastly, commenting on the slow rate of brain expansion and how modern advances in technology and culture will have an effect on evolution is akin to equating how the Kardashians will effect the Sun’s eventual implosion. The sum of the pressures of selection occur with drift. The time frames of history, in the thousands of years are too small to capture this phenomenon. A genetic example to outline this, is the Black Plague. European communities show much lower genetic diversity because of mass death that wiped out large populations, it had almost a nil effect on our genetic traits as a whole.

Like any progressing variable, time and culture offer different selective pressures upon the evolution of humans. While on one hand we maybe selecting for people with deleterious traits by offering IVF and C-sections to those who wouldn’t normally become parents, we on the other hand can prevent the births of offspring with such traits by early diagnosis. Additionally, as our population continues to expand and cultures admix, can we with certainty say we see an impact on the genetic and phenotypic makeup of humans?

These questions lead me to ask, “What Should Human Evolution Be?”

The flutes are made from bird bone and mammoth ivory, and look similar to the more younger examples that were announced in 2009. Tom Higham is the lead author, and the man who I presume dated the bones; the paper includes Nick Conard.

In their paper, the authors discuss the importance of the Danube River in providing a corridor to funnel humans and their technologies into central Europe during the dawn of the Aurignacian. To support this claim, the Geißenklösterle site has yielded more than just these flutes. The researchers have found personal ornaments, figurative art, mythical imagery and musical instruments from the cave, all dating to a period before the beginning of an ice age around 40,000 years ago. Highman writes,

“[Modern humans] were in Central Europe at least 2,000-3,000 years before this climatic deterioration, when huge icebergs calved from ice sheets in the northern Atlantic and temperatures plummeted… The question is what effect this downturn might have had on the people in Europe at the time.”

Higham, T., Basell, L., Jacobi, R., Wood, R., Ramsey, C., & Conard, N. (2012). Τesting models for the beginnings of the Aurignacian and the advent of figurative art and music: The radiocarbon chronology of Geißenklösterle Journal of Human Evolution DOI: 10.1016/j.jhevol.2012.03.003

“We assume that during the digging of a hole in the ground for a person who had just died of the plague, the gravediggers cut off the ID 6 deposition. They noticed the shroud (its presence is suggested by the verticalization of the clavicle) and a hole, which corresponded with the mouth. As the body appeared as quite intact, they probably recognized in that body the so-called vampire, responsible for plague by chewing her shroud. As a consequence, they inserted a brick in her mouth. The sequence of those events (time since death) can be deduced by the lack of alteration on the skeleton joints, so that we can suppose that the gravediggers dealt with the corpse when it was not disjointed yet. The insertion of the brick into the mouth at the time of the primary deposition can be ruled out because we have no reference, even folkloric, for such a practice in that historical and cultural context.

It is not strange that superstitions concerning vampires were widespread in the 16th to 17th centuries even in a “cosmopolitan” and evolved city like Venice. It is surprising, however, that this exorcism ritual has been clearly recognized in an archaeological context: the ID 6 grave could well be the first “vampire” burial archaeologically attested and studied by a forensic odontological and anthropological approach.”

Minozzi, S., Fornaciari, A., & Fornaciari, G. (2012). Commentary on: Nuzzolese E, Borrini M. Forensic approach to an archaeological casework of “vampire” skeletal remains in Venice: odontological and anthropological prospectus. J Forensic Sci 2010; 55(6):1634-37 Journal of Forensic Sciences, 57 (3), 843-844 DOI: 10.1111/j.1556-4029.2012.02100.x

The talk was engaging. Many people got a chance to ask questions. This was an outstanding feature of this format in this sort of venue. Most lectures I’ve been to leave such pressed time for questions that only 2-3 get fired away. That often leaves patrons at a loss. But SciCafe did it well, offering a good hour or so of discussion.

Nina’s talk is a good segway into some news that I came across today. As we know blond hair is a phenotype and carried by at least one a recessive allele in European populations. But many Oceanic peoples also have blonde hair, specifically those from Melanesia — distinct from Polynesia and Micronesia.

Melanesian Blond Hair

In a new Science paper, researchers identified a new missense mutation in TYRP1 in about half of the blondes in Micronesia which was not found in any of the 900 other individuals sampled from outside the South Pacific. This novel blond mutation in Solomon Islanders is thought to have popped up around 10,000 years ago. Furthermore, it appears to be the same one behind blondness in Fiji and other regions of the South Pacific.

Nina Jablonski eluded to the evolution of lighter phenotypes, like light skin occurring at least twice in the evolution of Homo sapiens and at least once in Homo neanderthalensis. But light skin need not be light hair, which is often a misconception. Research like this shows us that in dark-skinned people, one base pair mismatch leads to light hair.

Kenny, E., Timpson, N., Sikora, M., Yee, M., Moreno-Estrada, A., Eng, C., Huntsman, S., Burchard, E., Stoneking, M., Bustamante, C., & Myles, S. (2012). Melanesian Blond Hair Is Caused by an Amino Acid Change in TYRP1 Science, 336 (6081), 554-554 DOI: 10.1126/science.1217849

I’ll be following the project, but honestly I don’t have high hopes. I would love to be proven wrong. It seems lofty, using a lot of high yield buzzwords. My first impression was if this nothing more than a CV booster … Especially since it hasn’t been updated since last September. I guess it can’t be completely an empty shell because they have an impressive member on research team, Pardis Sabeti.

You can learn more about this project by checking out their site, watching the following video and following them on Twitter: @irangenes. If you want, you can participate in the project by filling out this survey.

A draft of the genome was released shortly afterwards in December, 2010. Today, after 30-fold coverage of the genome using Illumina GAIIx sequencing platform, the complete genome was released. It is free to download and use on Amazon Web Services… weighing in at 160gb.  I can imagine a lot of interesting comparisons can be made with this dataset and am happy the researchers made it available to the public.  There’s a caveat though, you can use the data but however agree that you cannot publish your findings until the researchers at Max Planck first get a stab at it.

I’m approaching my last semester as an undergraduate at Binghamton University, and if you haven’t guessed it by the context of this blog already, my envelopes were addressed to graduate schools of anthropology.

Now that I have almost finished paying a small fortune in application fees to play a lottery, I have had the time to start to catch up on some reading. While prospective graduate students might feel pessimistic about waiting to hear back about acceptances, what I’ve been skimming has sobered me up a little bit from my fall daydreams of excavations in faraway places.

I found myself searching the web reminding myself how as an anthropologist you should never expect to ever really get hired by a university. Not to say that I learned anything new.

There aren’t a lot of tenure track positions. You’re just going to have a lot of debt. It will take you a literal lifetime to pay back your loans. You’re going to be an adjunct professor and be paid less than a graduate student on a fellowship. Just don’t expect to work in academia.

That is a lot of negativity, but everyone has heard something similar. The most positive remark I hear about careers in academia is that the job market just can’t get any worse.  Surely by the time I finish my graduate work in a decade things will have turned around some, right?

For some reason like many others I am not dissuaded or in the least bit fazed by the outlook, at least at this stage in my aspirations. It is important to note I recognize that I am still in my naïve undergraduate phase. I hear in the long years of graduate school it becomes easier to get disillusioned. For now I am content. Call it unrealistic, but I’ll work my hardest and keep my fingers crossed.

I feel like most of my peers too have their eyes on the prize of a tenure track position, some time down the road. They too probably brush off knowing that very specific job listings for such positions receive hundreds of applications.

Knowing the odds, I am very curious what percentage of individuals starting work on a PhD have the intention of working somewhere other than a university. Are there a lot of you out there?

How many of you have thought about other applications of highly specialized degrees? If in eight years I am an expert on Neandertal lithic industries in southwest Belarus—as a random example– what jobs are most likely for me? Cultural resource management? Museum work?

I suppose it is something I can start thinking about, assuming I get in somewhere. If I am accepted I will have a solid seven years to mull over future directions, which should be sufficient time. Right now I am looking forward to it.

By Matthew Magnani

Researcher extracts DNA from a Neandertal specimen

The company known as 23andMe recently released an analysis that claims to answer precisely this question. While personal genome sequencing has not yet hit the mainstream market, 23andMe looks at SNPs, or variations in single nucleotide pairs. Through a comparison between your SNPs and those found in the Neandertal genome draft, for a couple hundred dollars you will be given a percentage. The service has been given the name “Neanderthal Ancestry Estimator.”

Computational biologist Eric Durand developed the project, and has previously worked on both the Neandertal genome draft and Denisova genetics.

I encourage you to take a look at an outline of the methodology, online in a white paper. Are we really at the point where a private company can tell us a likely percentage of our Neandertal ancestry for $207? I’ll let you be the judge.

By Matthew Magnani

Based on the skeletal remains, how can we ascertain specifics about hominin diet? For this particular study, researchers used microwear analysis on two molars from Dmanisi. Microwear analysis observes the patterning left on teeth by components of specific diets. As one example, tough silicates in plants leave identifiable traces, as do other silica-based sands that end up being chewed.

Comparisons in wear patterns were made with Dmanisi H. erectus and African H. erectus as well as the genus Australopithecus and earlier Homo, to get an idea of where the Dmanisi hominins fit in on the spectrum of microwear diagnostic traits. These diagnostic traits include heterogeneity of the tooth surface, as well as complexity in the roughness of the tooth surface. To give you an idea of general evolutionary trends, Australopithecines typically had larger teeth and thicker enamel to break down tougher, lower quality foods. As later Homo emerged, teeth tended to get smaller and enamel thinner.

The results indicated that the molars of Dmanisi Homo erectus were very similar to African Homo erectus in general. However, there were also characteristics found to be consistent with other earlier hominin species. Overall the authors cautioned against drawing conclusions with such a small number of teeth, saying that meaningful statistical results are unattainable based on the sample size.

According to authors, the wear patterns on the Dmanisi teeth are indicative of hominins that exploited a range of foods. It seems then that versatility and not specialization is what defines H. erectus in both Africa and Europe. The ability to take advantage of a larger resource base is no doubt one of the factors that allowed the first hominins to spread out across such an expansive area.

By Matthew Magnani

Pontzer, H., Scott, J.R., Lordkipanidze, D., Ungar, P.S. 2011.“Dental microwear texture analysis and diet in the Dmanisi hominins.” Journal of Human Evolution 61:683-687.

Australian Museum.

A lot had happened this year with hominin research and some would redefine conventional understandings of this group. Below is a list of new studies that came out this year that I find quite interesting on hominin. Read up so you can show off in class with your knowledge of current hominin research. You know, just so you can make sure that your adjunct is really paying attention of what he/she is doing instead of begrudgingly teaching a class because he/she has to. Or maybe you have a geeky classmate you want to impress. Or if you’re like me, you just wanna be the smartest in class because Asian Fail is not an option. So, enjoy … and if they question you, tell them I said so.

Australopithecus africanus and Paranthropus robustus

• Male philopatry and female dispersal in both A. africanus and P. robustus. Is this a strategy to prevent inbreeding and mate choice by females? Ancient Hominid Males Stayed Home While Females Roamed, Study Finds

Paranthropus boisei

• Seems like we’ll have to re-evaluate P. boisei‘s nickname, “Nutcracker Man”. Recent study showed that P. boisei didn’t eat nuts but instead used its big teeth to chew on grasses and sedges. No nuts for ‘Nutcracker Man’: Early human relative apparently chewed grass instead

Homo erectus

• H. erectus were the first to controlled fire but it wasn’t just used for warmth. New study shows that H. erectus were the first to cook their food (with fire) and process their food with tools. Homo Erectus Processed Food Like Humans, Harvard Scientists Say

• Stone artifacts, mostly flakes from stone tools, from the Dmanisi site in Georgia (the country, not the state) might suggests that H. erectus evolved outside of Africa. However, no conclusive evidence can be made due to the poor conditions of fossils found near these artifacts. Human ancestors in Eurasia earlier than thought

• H. erectus reached South Asia earlier than previously thought, between 1.5 to 1 million years ago according to Acheulean tools. Go east, ancient tool makers

• Findings from Solo River Terrace (SoRT) in Indonesia shows that H. erectus never coexisted with H. sapiens. Using three dating techniques: U-series, Electron Spin Resonance (ESR) and argon-argon, scientists found H. erectus went extinct between 143,000 to 550,000 years ago. H. sapiens are thought to reached Indonesia about 40,000 years ago. Human Ancestor Older Than Previously Thought; Finding Offers New Insights Into Evolution

Homo neanderthalensis

• Neandertals probably died off because there were too many early humans to compete with. According to a statistical analysis, the Périgord region of southwestern France has the highest concentration of Neandertals and early humans. The ratio between Neandertal to early human was 1 to 10. There were just too many humans for Neanderthals to survive

• Mousterian culture might have lasted longer than previously thought and Neandertals might have spread as far as northern Russia in the mountains of Polar Urals, near the Arctic Circle. Last Neanderthals Near the Arctic Circle?

• Neandertals were predominantly right-handed, according to their teeth. Also, humans have been predominantly right-handed for at least 500,000 years. Neanderthal ancestors were mostly right-handed

Homo floresiensis (the Hobbits)

• The debate whether H. floresiensis is a separate species or just microcephalic H. sapiens continues on. New study shows that the measurement of the Hobbit skull is within the range of microcephalic H. sapiens. Taking the measure of a hobbit

From left to right: Homo floresiensis (LB1) and Homo sapiens.

Homo sapiens (early and modern humans)

• Early humans have been playing hanky panky with Neandertals and possibly the Denisovans. Proof? A toe bone and its DNA. Stone Age toe could redraw human family tree

• A particular segment of our X-chromosome were inherited from Neandertals. This supports the hypothesis that early humans interbred with Neandertal. However, only non-African humans have this segment. Confirmed: All non-African people are part Neanderthal

• Might not be a conscious decision, but apparently early humans that left Africa interbred with Neandertal to protect themselves against diseases. This is probably an unintended result more than an active thought process. First modern humans protected themselves against disease after leaving Africa by ‘interbreeding with Neanderthals’

*Bouchra child, Homo sapiens*

• Dr. Harold Dribble and his team found the skull of “world’s oldest human child” dated around 108,000 years old in Morocco and nicknamed it Bouchra. The boy died when he was 8 years old. This specimen has not been described in any scientific paper so watch out for it soon. World’s Oldest Child Found in Morocco