Archive for May, 2006

Fewer people graduating with science & tech degrees

By Razib Khan | May 31, 2006 5:28 pm

Percentage of Students Earning Degrees in Science and Math Has Fallen, GAO Tells Lawmakers ($$$), but this is all you need to know:

The GAO reported that 27 percent of students obtained degrees in those fields, which are known as the STEM disciplines, in the 2003-4 academic year, compared with 32 percent in 1994-95. It also noted that the number of degrees obtained in engineering, the biological sciences, and certain technical fields declined in the past decade. The number of graduate degrees awarded in the STEM fields also declined, it said.

Percentage is crucial. More & more people go college, but it may simply be that the inclination and aptitude for technical disciplines was long ago tapped out. And frankly, my personal experience is that many of the “Studies” (but not all) are joke degrees. A friend who did biochemistry and international studies told me that the latter felt like what she could have learned in coffee shop bull sessions.


Open access the people say!

By Razib Khan | May 31, 2006 4:50 pm

Apropos of this week’s Ask a Science Blogger, AMERICANS SUPPORT FREE ACCESS TO RESEARCH. Not that their opinion matters!


Global warming = biodiversity (in the future)

By Razib Khan | May 31, 2006 3:35 pm

The title is tongue in cheek, some researchers now are suggesting that speciation may be proportional to a particular energetic value. R.A. Fisher wanted an “ideal gas law” for evolutionary genetics, but this is ridiculous! In any case, one issue that many of us who are interested in paleoanthropology will have noted is that Africa seems to have been the repeated mother of hominid species. That is, “erectus” left around 2 million years ago, only to be swept aside by moderns around 50,000 years ago. Why Africa twice? This might be part of the answer, and is a flip to WIlliam H. Calvin’s Ice Age driven hypothesis in A Brain for all Seasons.


Roaring out of Africa

By Razib Khan | May 31, 2006 12:00 pm

This lion research is just cool. Hey, I’m human, I’m a sucker for cats, and the bigger the better:

Understanding the phylogeographic processes affecting endangered species is crucial both to interpreting their evolutionary history and to the establishment of conservation strategies. Lions provide a key opportunity to explore such processes; however, a lack of genetic diversity and shortage of suitable samples has until now hindered such investigation. We used mitochondrial control region DNA (mtDNA) sequences to investigate the phylogeographic history of modern lions, using samples from across their entire range. We find the sub-Saharan African lions are basal among modern lions, supporting a single African origin model of modern lion evolution, equivalent to the ‘recent African origin’ model of modern human evolution. We also find the greatest variety of mtDNA haplotypes in the centre of Africa, which may be due to the distribution of physical barriers and continental-scale habitat changes caused by Pleistocene glacial oscillations. Our results suggest that the modern lion may currently consist of three geographic populations on the basis of their recent evolutionary history: North African-Asian, southern African and middle African. Future conservation strategies should take these evolutionary subdivisions into consideration.

I’ve put two images of interest from the article below the fold.

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Another model on human demographic expansion out of Africa

By Razib Khan | May 31, 2006 9:00 am

The American Journal of Human Genetics has a paper in its pre-print section titled “A geographically explicit genetic model of worldwide human settlement history.” I quickly skimmed it (and uploaded it into the GNXP forum). I have serious issues some of the inferences made in regards to the “obvious” fit of such coalescence data with a particular demographic history. I am convinced that meta-population dynamics tend to be ignored (in part because they are just another complication) even though they can also explain the data. Nevertheless, this jumped out at me:

We further neglected key events such as spatial and temporal environmental variation. Our results thus suggest that various environmental factors tend to be spatially relatively homogenous for human migration patterns, when considered over a large geographic distance.

As I stated above, meta-population dynamics, local extinctions and recolonizations, are issues that the authors seem to ignore when it comes to ignore their there results, especially given that environmental parameters are likely to be very relevant to marginal groups. They even allude to what seems like an abortive extra-African colonization in the Levant by anatomically modern H. sapiens sapiens which ended in local population extinction. But, the idea that humans are relatively buffered from environmental variation is roughly correct, and I’m talking about “humans” in a very broad sense. Our genus, Homo, broke out of the African continent almost immediately after its genesis. Dmanisi shows that beyond a shadow of a doubt.


Evolutionary genomics and the human brain

By Razib Khan | May 30, 2006 7:40 pm

PLOS Genetics has a nice review titled The Jewels of Our Genome: The Search for the Genomic Changes Underlying the Evolutionarily Unique Capacities of the Human Brain. It is short and pithy and hits the major points (e.g., SNPs vs. duplications vs. gene expression), so I see no reason to offer any commentary or review of an an already satisfactory commentary and review. If you want original research articles in this area, go here. Some of the material is even open access now.
Update: John Hawks has more.


DRD4, sex and Jews

By Razib Khan | May 30, 2006 3:20 am

I was pointed to this research (via David) that is just out about the correlation between variation on DRD4 and “sexual arousal.” From the press release:

Interestingly, some forms of variants in this gene were shown to have a depressing effect on sexual desire, arousal and function, while other common variant had the opposite effect – an increase in the sexual desire score. The latter is believed to be a relatively new mutation, and it is estimated that it appears in Homo sapiens “only” 50,000 years ago at the time of humankind’s great exodus from Africa. Approximately 30% of many populations carry the heightened arousal mutations, while around 60% carry the depressant mutation.

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By Razib Khan | May 26, 2006 4:35 am

I don’t know what to think about this year’s idol winner, but hey, perhaps he won’t be a closeted gay man always in image control mode because of his “secret” (not that there’s anything wrong with that!). As for the runner up, best of luck to her, I know how it feels….


Feline rising

By Razib Khan | May 26, 2006 3:40 am

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Brown, itz not a bug, itz a feature

By Razib Khan | May 25, 2006 8:37 pm

My friend Manish Vij just started a new brown themed weblog, aptly titled UltraBrown. Anyway, this entry is hilarious. Talk about seeing the world only through your own lens! When I was in San Francisco once someone came up to me in a shop at Ghirardelli Square and asked “where I was from.” You see, I had bleached my hair blonde at that point, so she was wondering where the land of brown-skined blondes was! (there are dark-skinned blondes among the Aboriginals of Australia)


Ask a Science Blogger – "Justify my funding"

By Razib Khan | May 25, 2006 6:51 pm

This week’s “Ask a Science Blogger” is:

Since they’re funded by taxpayer dollars (through the NIH, NSF, and so on), should scientists have to justify their research agendas to the public, rather than just grant-making bodies?

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CATEGORIZED UNDER: Ask a ScienceBlogger

Looking inside the mind….

By Razib Khan | May 25, 2006 4:50 pm

I had a strange experience the other day. I was walking down a hallway, and all of a sudden the name of a local software company came to mind. I didn’t understand why I was thinking about this, and I was mulling over this strange issue when 20 seconds after I’d started thinking about the company in question, a woman to my right nodded in my direction (she was a few people over). And bingo, all of a sudden I realized why I’d been thinking about that company, the woman was the roommate of another individual who I knew worked at that company. The peculiar thing is that it is clear that one part of my mind (“human recognition”) realized who the individual out of the corner of my field of vision was, and somehow that triggered cogitation about a software company that I associated with this individual. But, my conscious mind was totally unaware of this until after the fact.
Anyway, it was pretty strange at the time, though perhaps I could conclude I have psychic powers and my prescience about the relationship of this individual who was going to get my attention was simply a way of my mind of priming me. I don’t know :)

CATEGORIZED UNDER: Cognitive Science

Let's talk about sex….

By Razib Khan | May 24, 2006 2:36 am

PLOS has a new paper out which fleshes out how SRY might play a critical role in sex determination in mammals. Here is the press release. Below the fold I’ve taken figure 7 from their paper and cropped and reedited it a bit for ease of viewing, as well as adding minor parenthetical remarks (e.g., I assume most readers know the common symbol for repression in molecular genetic models, but some might not). Molecular genetics really isn’t my thing, but it is good to know if we are interested in the phenotypic impact of a particular locus (e.g., SRY) the particular genotypic dynamics that underlay it.1 Also, I’ve reviewd the sex determination literature in mammals recently (which was smaller than I’d expected), and it did surprise me that females were not just the “default” pathways as I’d expected, there is active suppression of the development of the Mullerian ducts in male embryos.
1 – The reason it isn’t my thing is that some molecular genetics people seem to only give a perfunctory nod to evolutionary thought in their fixation on specific processes. That’s fine, but it seems tome that Theodosius Dobzhanksy’s assertion that nothing in biology makes sense except in the light of evolution could be modified to biology is more fun if you add an evolutionary angle to your thinking. See Genes in Conflict. I mean that’s what science is supposed to be about, right? Having fun on the NSF and NIH’s dime :)

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God lives, deal with it!

By Razib Khan | May 23, 2006 7:52 pm

I’m an atheist. Just like some people who are Christians but weren’t always tell me that they “always believed in Christ,” myself, I’ve never believed in God. Before the age of 7 I did avow a belief in God, but in hindsight I see only the most minimal of deisms in my conception of the world aside from the times when I was at the mosque with my family. Religion wasn’t talked about in my family much aside from major festivals, and it wasn’t something I ever really thought about. When I was 7 I was in the library, reading some books on astronomy, and it struck me that there was no reason for God to exist (aside from people telling me that he did exist, or assume that he did). In that moment my implicit atheism crystalized into my conscious explicit mind.
I offer this to preface a note about something that really irritates me about some atheists, and that is a combination of distinterest in, and, rejection of the worldly importance of, religion. This does not mean that I am annoyed by those who contend that religion is not important for personal happiness, or morality, or any other such thing. I think that people like Richard Dawkins have a role to play as a force for skepticism in a demon haunted world. No, what I mean is that people who wish to dismiss the importance of understanding, knowing and engaging religion and religious ideas. This is why this asinine comment rubbed me the wrong way, it seemed the only reason that the individual commented was to state that religion is obviously ridiculous, and there’s no point in discussing it in a serious fashion.

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Social life & genomic imprinting

By Razib Khan | May 23, 2006 10:01 am

My post yesterday offered up a quick sketch of the phenomenon of genomic imprinting. In short, genomic imprinting is the selective expression of an allele conditional upon whether it is inherited from the father or mother. This selective expression is limited to a small subset of loci, perhaps about 200 in the typical mammal. These expression patterns often relate to conflicts over resources between offspring and mother, and have fitness implications for all individuals in question, mother, father and offspring. All of this is derived from the initial logic that maternal and paternal copies of alleles might have different interests in regards to resource allocation between mother and offspring. This makes sense, doesn’t it? You have parents, and your father wants you to suceed at all costs, no matter the harm to your mother. Wait you say, back up, something doesn’t sound right. And yes, I left something out….

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Da Vinci & DNA – Jesus with the XX male syndrome?

By Razib Khan | May 22, 2006 11:14 pm

Since I’m on a Dumb Vinci Code kick today, check out this amusing article about the genetics of Jesus! Check it:

In humans, females package some of their DNA in two matched X chromosomes, males in a single X and Y. So if you’re a male, there’s only one way you could have gotten your Y chromosome, and that’s from your biological father.
Where would Jesus have gotten his Y?

Where indeed. Perhaps Jesus Christ was an XX male? In other words, he was a clone of Mary that was miraculously possessed of an SRY.


Why The Dumb Vinci Code matters to America, you and I

By Razib Khan | May 22, 2006 3:27 pm

Below GrrlScientist asks why The Da Vinci Code is “bad history.” I believe it is bad history because someone whose work I respect and have enjoyed has pointed out manifold errors, incluing in a book which covered this ground. His name is Bart Ehrman, and he is the head of Relgious Studies at UNC. I’ve read two of his books, Lost Christianities and Misquoting Jesus. Erhman went through a phase of fudamentalist Christianity, but his need to know the New Testament in the original led him to learning Latin and Greek, and a Ph.D. In the process, he became an agnostic.

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Kinship theory and genomic imprinting

By Razib Khan | May 22, 2006 1:19 pm

Some of the most fascinating theoretical evolutionary biology that I’ve run into emerges out of David’s Haig’s work on genetic conflict. You’ve probably stumbled into it somewhere, whether via popularizers like Matt Ridley, or other researchers like Robert Trivers and Sarah Blaffer Hrdy. Haig is a biologist who extrapolates from the familiar axioms of evolutionary genetics and hacks his way through the jungle of derivations and wanders into a world turned upside down. Though his work in the area of mother-offspring genetic conflict in utero is probably what is in widest circulation in the public mind space, Haig’s refinment of “kinship theory” of genomic imprinting is a far more general paradigm, and nearly as accessible.

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Reading the Dumb Vinci Code

By Razib Khan | May 22, 2006 9:55 am

Conservative Christian Pollster George Barna has an interesting report out on those who have read the book, The Da Vinci Code. Some results:

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You germy fat pig….

By Razib Khan | May 22, 2006 2:42 am

Interesting article in The Boston Globe which profiles researchers who suggest that variation in gut flora (the mix of bacteria) might be the cause of differences in body weight. Interesting fact: there are an order of magnitude more bacteria in your gut than cells in your body. Also, to my knowledge (hearing this from a microbiologist last year) this gut ecosystem hasn’t really been replicated in the lab, so that kind sucks for a scientific understanding beyond description.
Update: An expert comments.


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