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Penn geneticists identify genes linked to Western African Pygmies’ small stature

Nature If Pygmies are known for one trait, it is their short stature: Pygmy men stand just 4’11" on average. But the reason why these groups are so short and neighboring groups are not remains unclear. Scientists have proposed various theories based on natural selection, including that Pygmies’ reduced size lowered nutritional requirements, helped them better handle hot climates, or allowed them to reach sexual maturity at an ear Read more...

How the Amhara breathe differently

I have blogged about the genetics of altitude adaptation before. There seem to be three populations in the world which have been subject to very strong natural selection, resulting in physiological differences, in response to the human tendency toward hypoxia. Two of them are relatively well known, the Tibetans and the indigenous people of the Andes. But the highlanders of Ethiopia have been less well studied, nor have they received as much atten Read more...

Most Reported Genetic Associations with General Intelligence Are Probably False Positives

The title says it all, and I yanked it from a paper that is now online (and free). It’s of interest because of its relevance to the future genetic understanding of complex cognitive and behavioral traits. Here’s the abstract: General intelligence (g) and virtually all other behavioral traits are heritable. Associations between g and specific single-nucleotide polymorphisms (SNPs) in several candidate genes involved in brain function h Read more...

Study shows species can change

Nature A study of South American songbirds completed by the Department of Biology at Queen’s University and the Argentine Museum of Natural History, has discovered these birds differ dramatically in colour and song yet show very little genetic differences which indicates they are on the road to becoming a new species. "One of Darwin’s accomplishments was to show that species could change, that they were not the unaltered, immutab Read more...

Study finds new ADHD genes, links susceptibility with autism and other neuropsychiatric conditions

The study is published in the August 10 advance online edition of Science Translational Medicine. The research team was led by Dr. Russell Schachar, Senior Scientist and Psychiatrist at SickKids and Professor of Psychiatry at the University of Toronto, and Dr. Stephen Scherer, Senior Scientist at SickKids, Director of The Centre for Applied Genomics at SickKids and the McLaughlin Centre at the University of Toronto. The scientists used microarra Read more...

Micro-RNA’s contribute to risk for panic disorder

The pattern of these implicated genes raises the question of whether there might be molecular “switches” that control the function of groups of genes in a coordinated fashion, which would help to explain the observed findings related to the genetics of panic disorder. A new study published in the current issue of Biological Psychiatry now implicates one type of molecular switch, microRNAs (miRNAs), in panic disorder. Ribonucleic acid Read more...

Gene linked to ADHD allows memory task to be interrupted by brain regions tied to daydreaming

Presented at the annual meeting of the Society for Neuroscience, these researchers believe their findings are the first to show, through brain scanning, the differences in brain network relationships between individuals with this particular form of gene and others with a different form. “Our goal is to narrow down the function of candidate genes associated with ADHD, and in this study, we find this gene is tied to competition between brain Read more...