genetics
razib | November 19, 2008That's the question being asked at The Personal Genome. Over at Genetic Future Dan "The Man" MacArthur notes the difficulties which might emerge if we start engaging in widespread embryo screening. So how exactly is the average American voter going to interpret the myriad of genes responsible for only a small fraction of phenotypic variation?
I'm not sure that genetic data adds much value for the body politic. I would want to know, but, I would also take SAT scores and college transcripts before I'd be interested in a candidate's genetic sequence. Our president elect has not, for example…
edyong | November 19, 2008About 18,545 years ago, give or take a few decades, a woolly mammoth died. Succumbing to causes unknown, the creature was buried in Siberian snow. Many other mammoths must have met similar fates but this one, which we now know as M4, is special. Almost 20 millennia later, its beautifully preserved remains were unearthed by scientists who have revealed both its body and its genetic code. For the first time, the genome of an extinct species has been sequenced almost to completion.
Webb Miller from Pennsylvania State University together with a large team of American and Russian scientists has…
clock | November 19, 2008There is an utterly confusing press release out today - Australian First: Kangaroo Genome Mapped:
Australian researchers are launching the world first detailed map of the kangaroo genome, completing the first phase of the kangaroo genomics project.
Why is it confusing?
Because we are used to seeing press officers and media botch the terms. They often use the words "map" and "sequence" interchangeably.
Mapping a genome means locating genes on chromosomes, i.e., you get to know where each gene is on each chromosome. For this, you do not need to know the sequences of any genes, and certainly…
razib | November 18, 2008Refugee program stayed after feds confirm fraud:
DNA testing conducted earlier this year by the government to verify blood ties between anchor refugees and their supposed family members revealed that fewer than 20 percent of those checked could confirm their biological relationships, the fact sheet stated.
Doesn't matter how high "paternity uncertainty" is in a culture, this is just way too high a number.
edyong | November 18, 2008There's a glut of awesome science coming out towards the end of this week and not much at the start, so I'm sticking the Revisited post up early (it's usually on a Saturday) to clear the schedule later.
Imagine you are a man who has just learned, through a genetic test, that your son carried your brother's genes instead of your own. You might well have some stern words to exchange with your partner. But if you were a marmoset, this would all be part and parcel of life.
In a striking new study, scientists from the University of Nebraska have shown that marmosets inherit genes not only…
razib | November 16, 2008Kambiz's review (pointer) to the Humanity's Genes an the Human Condition conference made me aware of Jean-Laurent Casanova's research. His general idea seems to be that heightened susceptibility or death due to infectious disease is in large part a function of inter-individual genetic variation. Among the young this is due to Mendelian genes of large effect, whether it be dominant or recessive (higher frequency among those who are the product of cousin marriage). For the old he suggests that it might be due to QTLs of small effect, just like schizophrenia. To some extent this is a revision…
sb admin | November 16, 2008
Population biologists often want to infer the demographic history of the species they study. This includes identifying population subdivision, expansion, and bottlenecks. Genetic data sampled from multiple individuals can often be applied to study population structure. When phylogenetic methods are used to link evolutionary relationships to geography, the approaches fall under the guise of phylogeography.
The past decade has seen the rise in popularity of a particular phylogeographical approach for intra-specific data: nested clade analysis (Templeton et al. 1995; Templeton 2004). Many of…
razib | November 15, 2008Kambiz attended the Humanity's Genes and the Human Condition, and he reports some interesting goings on. Sydney Brenner, Nobel Laureate 2002, had this to say this about human evolution:
Starts off with a zinger: "Biological evolution for humans has stopped." Uhh, really Sydney? You better do better than that. He uses an analogy about how if we feel cold, we don't 'adapt' we just kill an animal, skin it, and wear its pelt as evidence of relaxed natural selection.
I wonder if this the malevolent influence of Steve Jones, but I doubt it. But that wasn't the weird stuff:
Obesity! Lists how…
gregladen | November 14, 2008The paper I'm about to discuss is a minefield of potential misconceptions that arise from the way we often use language do describe natural phenomena. This is a situation where it would be easier to start with a disclaimer ... a big giant obvious quotation mark ... and then use the usual misleading, often anthropomorphic language. But I don't think I should do that. We'll address this research the hard way, but the result will be worth the extra work.
Here is the basic hypothesis. The null model is that genetic variation arises randomly and this variation is the raw material on which…
edyong | November 14, 2008When we think about cooperative behaviour, most of us would think of animals like ants, meerkats, lions or, indeed, humans. But don't rule out yeast. The small, single-celled fungus has provided us with much of our knowledge of genetics and molecular biology and now, it's shedding light on the evolution of cooperation too.
The budding yeast, Saccharomyces cerevisiae, is one of the most widely studied of laboratory microbes, but scientists mostly know it as a solitary species. Brewers, on the other hand, use S.cerevisiae to make beer and are all too aware of its social side. Their strains…
evolgen | November 12, 2008You would think that geneticists would have a good definition of "gene". After all, genes are what we study. In introductory biology courses, you may have been introduced to the concept of the gene as the unit of heredity. That's all well and good, but when you begin to study genes at a molecular level (i.e., looking at DNA sequences), that definition ceases to be practical. The advent of DNA sequencing led to the concept of the gene as an open reading frame, and the post-genomic era has challenged the very idea of the gene.
I've previously discussed the definition of gene (What is a gene?,…
razib | November 10, 2008Chorus of demands to let doctor Bernhard Moeller stay:
The Rudd Government is under pressure from all fronts, even Labor colleagues, to overturn a decision denying German doctor Bernhard Moeller permanent residency in Australia because his son Lukas has Down syndrome.
The Immigration Department this week rejected Dr Moeller's application for permanent residency, saying the potential cost to the taxpayer of 13-year-old Lukas's condition was too great.
This is not to say that government backed health care is right or wrong, but it is a reminder that transferring responsibilities from the…
gregladen | November 10, 2008 Cute baby lion kittens. When they grow up, they will want to eat you. I'll never forget the first wild lion I ever saw. It was a pitch black night, on the savanna in the Western Rift Valley. I had climbed on top of the hood of the Land Rover, engine off, but headlights on. My plan was to search the horizon for lights indicating the presence of the research camp I was trying to find. Once I was on the hood, I was about to tell my colleague, still in the vehicle, to cut the headlights so I could see better. That's when she walked into view.
She was a fully adult lioness. Eventually…
razib | November 10, 2008You know what the Human Genome Diversity Project (HGDP) is implicitly, they're the list of populations you've seen in many human genetics papers already. Now the Pritchard lab has put up a nice browser to query the data in a manner analogous to Haplotter. One of the major improvements, aside from the fact that you're looking at 52 populations instead of 3, is that it uses GET to pass parameters instead of POST. That means I can link to the queries for KITLG and SLC24A5. Try it, it works! Under instructions it is laconically stated that:
Search using a sequence name, gene name, locus, or…
razib | November 9, 2008Notes on Sewall Wright: The Shifting Balance Theory (Part 2):
Part 1 of this note dealt with Sewall Wright's Shifting Balance theory of evolution (the SBT) in its original form, as propounded between 1929 and 1931. This final part deals with subsequent developments in the theory. These include refinements and elaborations, some changes of emphasis, one major addition, and one major change of substance. In particular I will cover:
1. The role of new mutations
2. The concept of selective peaks
3. The effect of changes in environment
4. The adaptiveness of evolution
5. The process of intergroup…
razib | November 9, 2008Political Behavior through the Lens of Behavior Genetics:
These are all fascinating questions and Fowler and colleagues are only beginning to uncover the answers. I anticipate that Fowler and his partners in crime will continue to leave a trail of evidence from which we can build an even stronger case for a political science which does not make assumptions that are at odds with stylized facts from behavior genetics. Or, for that matter, at odds with facts derived from any of the other scientific disciplines from which the "genopolitics" crowd draw inspiration.
Read the whole thing, as the…
razib | November 7, 2008Anthropology.net & prefonal both have posts up which survey a new paper, A Functional Genetic Link between Distinct Developmental Language Disorders:
We found that FOXP2 binds to and dramatically down-regulates CNTNAP2, a gene that encodes a neurexin and is expressed in the developing human cortex. On analyzing CNTNAP2 polymorphisms in children with typical specific language impairment, we detected significant quantitative associations with nonsense-word repetition, a heritable behavioral marker of this disorder (peak association, P=5.0x10-5 at SNP rs17236239). Intriguingly, this region…
mikethemadbiologist | November 6, 2008Every time there's an article about species barcoding--using a short DNA sequence to identify species--there always seems to be people who get all het up:
Barcoding, which is something I have criticised and discussed before here, and here, treats species as things that have some invariant property (in this case, a segment of the COI gene) that maps directly onto the entities one-to-one. As Brent Mishler, head of the Berkeley herbarium, says
We're not accusing Hebert of being a creationist, just of acting like one.
Why? Because creationists treat species as having invariant properties.…
edyong | November 6, 2008Specific language impairment (SLI) is a language disorder that affects growing children, who find it inexplicably difficult to pick up the spoken language skills that their peers acquire so effortlessly. Autism is another (perhaps more familiar) developmental disorder and many autistic children also have problems in picking up normal speech and communication. These two conditions have a common theme of language difficulties running through them, but a new study reveals a deeper connection - both are linked to a gene called CNTNAP2.
The story of CNTNAP2 actually begins with another gene,…
razib | November 5, 2008Yes. This weblog is ostensibly about genetics. And yes, I've gotten a little obsessed about crunching election data. Honestly, I get a little bit like this every four years...I remember the '96 election and the primitive years of the internet even. I decided I might as well post on my fixation for a few days to get it out of my system. Be aware that you won't have to deal with any normative political arguments from me; I don't care enough about ought, or, more accurately I don't think you are really interested in my opinions about the Good Life and how to obtain it.
In any case, since…