genetics
razib | June 9, 2009
Domestication has a long history. It predates the invention of writing by thousands of years. In the history of biology the study of domestication is closely connected to the emergence of experimental and theoretical biology out of the shadow of natural history. Chapter I of The Origin of Species is preoccupied with animal breeding. The various modifiers of selection, artificial, natural and sexual, are to some extent human constructions. When the constraint of human preferences and needs are removed feral populations of dogs and pigs tend to shift back toward an ancient modal wild type. I…
grrlscientist | June 6, 2009tags: child stars, Disney, geneticists, satire, humor, funny, social commentary, streaming video
In this amazing news report, Disney claims its latest batch of child stars is so lifelike, you'll barely be able to tell they have no souls [2:40]
razib | June 5, 2009In Natural selection of a human gene: FUT2 I referred to a paper, Signals of recent positive selection in a worldwide sample of human populations (see my earlier review). Now the same group has a follow up paper which takes a slightly different tack, The Role of Geography in Human Adaptation:
Since the beginning of the study of evolution, people have been fascinated by recent human evolution and adaptation. Despite great progress in our understanding of human history, we still know relatively little about the selection pressures and historical factors that have been important over the past…
razib | June 4, 2009In the 19th & 20th centuries with the emergence of nationalism and its various scholarly subsidiaries in archaeology, philology and ethnography quite a few pan-ethnic movements rooted in language were born. Pan-Slavism, the Greater German idea (Grossdeutsch) and Pan-Arabism come to mind. As evident in their names these ideas shadowed relationships of language, but they often veered into racialist territory. In The History and Geography of Human Genes L. L. Cavalli-Sforza reported a substantial overlap between phylogenies generated from classical autosomal markers, and those of linguistic…
razib | June 3, 2009A few months ago I reviewed a paper which examined the various complexities of interpreting signals of natural selection from recently developed genomic tests in response to the avalanche of human sequence data. In the paper, Signals of recent positive selection in a worldwide sample of human populations, the authors state:
We find that putatively selected haplotypes tend to be shared among geographically close populations. In principle, this could be due to issues of statistical power: broad geographical groupings share a demographic history and thus have similar power profiles. However,…
razib | June 2, 2009Two interesting papers, one which relates KITLG and cancer, and another which connects ABCC11 and cancer. These are familiar genes. KITLG has been implicated in depigmentation, both of skin and hair. ABCC11 in earwax form and body odor. If you knock around a gene there is a high probability that you'll perturb multiple traits. Somethings the relationship between variation on a gene and pathology is more straightforward. Some of the genes responsible for normal human variation in pigmentation were originally of interest due to their implication in albinism, which is a disease with some non-…
edyong | May 29, 2009When Walt Disney created Mickey Mouse in 1928, he understood the draw that anthropomorphic mice would have. But even Walt's imagination might have struggled to foresee the events that have just taken place in a German genetics laboratory. There, a group of scientists led by Wolfgang Enard have "humanising" a gene in mice to study its potential relevance for human evolution.
The gene in question is the fascinating FOXP2, which I have written extensively about before, particularly in a feature for New Scientist. FOXP2 was initially identified as the gene behind an inherited disorder that…
razib | May 28, 2009
Nick Wade in The New York Times reports on new research where they inserted human FOXP2 genes into the mouse genome. Here are some of the findings:
Despite the mammalian body's dependence on having its two FOXP2 genes work just right, Dr. Enard's team found that the human version of FOXP2 seemed to substitute perfectly for the mouse version in all the mouse's tissues except for the brain.
In a region of the brain called the basal ganglia, known in people to be involved in language, the humanized mice grew nerve cells that had a more complex structure and produced less dopamine, a chemical…
razib | May 25, 2009Why We Stare, Even When We Don't Want To:
"When a face is distorted, we have no pattern to match that," Rosenberg said. "All primates show this [staring] at something very different, something they have not evolved to see. They need to investigate further. 'Are they one of us or not?' In other species, when an animal looks very different, they get rejected."
And so, we stare. (An averted gaze is triggered in some people. This too can be overridden only with great difficulty.)
It doesn't take much of a facial anomaly to trigger a transfixed response; a normal human face upside down will do it…
razib | May 25, 2009Dienekes points me to new research on MHC and mating:
The scientists studied MHC data from 90 married couples, and compared them with 152 randomly-generated control couples. They counted the number of MHC dissimilarities among those who were real couples, and compared them with those in the randomly-generated 'virtual couples'. "If MHC genes did not influence mate selection", says Professor Bicalho, "we would have expected to see similar results from both sets of couples. But we found that the real partners had significantly more MHC dissimilarities than we could have expected to find simply…
gregladen | May 24, 2009Junk DNA is like bigfoot. If a zoologist says something like "Hmmm... it would be cool to find bigfoot" all the other zoologists jump on him or her, drag the poor sap into the alleyway, toss on a blanket, and beat the scientist with rubber hoses until the movement stops. Same with junk DNA. If you mention that junk DNA may have a use or a role or something .... INTO THE ALLY WITH YOU!!!
The difference is, there is no bigfoot, but there may be some interesting stuff happening in the so called junk DNA.
Part of the problem is in what we call "junk." If it does something, it isn't junk. So,…
razib | May 24, 2009Waves of stationary shape:
Over at Scienceblogs, people are talking about waves. Of course, everyone thinks that waves are in the domain of physics, and people always forget about one of my favorite subjects: waves of advance. Way back in the day, RA Fisher wondered what might happen if genes had to spread not just locally but across space, and he published his findings in a landmark article called The Wave of Advance of Advantageous Genes. This paper was not just important for its contributions to population genetics, but because of fundamental contributions to applied mathematics. As far as…
razib | May 22, 2009It is well known that different ethnic groups vary when it comes to diseases such as Type II Diabetes. Or, more specifically they vary in terms of risk, all things equal (if you use an online Type II Diabetes calculator you'll see immediately as they sometimes have a parameter for ethnicity). American blacks for example are heavier than American whites. This seems to be true even when you control for socioeconomic status (though as Oprah once said, "You don't need to do a 'study' to figure that out"). There has been research on genetic loci correlating to obesity in European populations…
grrlscientist | May 21, 2009tags: book review, Why Evolution is True, evolution, creationism, religion, scientific method, Jerry Coyne
Considering the plethora of books about evolution out there, is it really necessary to publish yet another one? What can another book about evolution have to offer that previous books have not provided? This new book not only presents the latest information about evolution to come to light, but it also responds to the most recent attacks made upon this branch of scientific knowledge. The book, Why Evolution is True (NYC: Viking; 2009) by Jerry Coyne, is the most up-to-date and one of the…
razib | May 21, 2009A few years ago I commented a fair amount on the topic of prosopagnosia, face blindness. Turns out that ~2% of the population can't really recognize faces, and this is a cryptic trait as many of these individuals have developed compensatory tendencies so that people don't know. Not only that, but there seems to be a strong genetic component so that it runs in families. At the time I was fascinated by this because it made me wonder at how much more "cryptic" variation there could be in the human population. It seems that face recognition is such a basic and universal "competency" that it is…
mikethemadbiologist | May 20, 2009While I'm away at ASM, here's something from the archives for you
When I read Olivia Judson's post about hopeful monsters, I didn't think she used the term correctly (here are some good explanations why), but I was surprised by Jerry Coyne's response.
First, the personal attack on Judson is unwarranted: when we reach the point where the serious challenge to evolutionary biology is the misuse of a discredited decades-old idea, as opposed to the politically powerful anti-science creationist movement, we're in a pretty good place. She made a mistake--I don't think her motives were self-…
razib | May 19, 2009400-500 years ago in the midst of the Great Dying somewhere the indigenous inhabitants of the New World suffered mortality rates on the order of 90-95%. This was almost certainly due to the facts of evolutionary history; the indigenous peoples had little defense against Eurasian pathogens. A result has been the reality that most of the New World is inhabited by European, African or mixed populations. But there are exceptions. In Mesoamerica there is still an indigenous dominated region from southern Mexico into the highlands of Guatemala. More substantially the highlands of the Andes, and…
razib | May 18, 2009There are several papers and letters in Nature Genetics on the relationship between menarche, menopause, etc. and genetics.
Meta-analysis of genome-wide association data identifies two loci influencing age at menarche:
We conducted a meta-analysis of genome-wide association data to detect genes influencing age at menarche in 17,510 women. The strongest signal was at 9q31.2 (P = 1.7 10-9), where the nearest genes include TMEM38B, FKTN, FSD1L, TAL2 and ZNF462. The next best signal was near the LIN28B gene (rs7759938; P = 7.0 10-9), which also influences adult height. We provide the first…
bioephemera | May 16, 2009Students and laypeople alike often view biotech patents with baffled disbelief. How is it possible to patent bacteria? Mice? Cell types and DNA sequences? How can someone else "own" gene sequences that all of us have carried inside our bodies since birth?
Honestly, as a biologist, the concept of patenting a gene doesn't really throw me for a loop. Think about it: although we all have genes, we can't read them unless we use a variety of lab techniques, many of them patented. In turn, reading the sequence isn't any use unless we know why we care - that this gene is relevant and can be used to…
razib | May 15, 2009Genome-wide Insights into the Patterns and Determinants of Fine-Scale Population Structure in Humans:
Studying genomic patterns of human population structure provides important insights into human evolutionary history and the relationship among populations, and it has significant practical implications for disease-gene mapping. Here we describe a principal component (PC)-based approach to studying intracontinental population structure in humans, identify the underlying markers mediating the observed patterns of fine-scale population structure, and infer the predominating evolutionary forces…