Saturday, January 30, 2010

A Book about Prices

Priceless: The Myth of Fair Value (and How to Take Advantage of It) by William Poundstone is an entertaining summary of the recent scientific literature about prices and uncertainty. Unfortunately it also reinforces one's dismay over the limitations of human reasoning ability in real-life practical situations.

Cooking as Courtship

Cooking as Courtship: a manual of sorts, exploring the ins and outs of love and friendship in the context of food - a charming book, also available in blog format.

Comparison of Human and Chimpanzee Y Chromosomes

Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content in Nature.
The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes, but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, achieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically in sequence structure and gene content, indicating rapid evolution during the past 6 million years. The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. Although genetic decay may be the principal dynamic in the evolution of newly emergent Y chromosomes, wholesale renovation is the paramount theme in the continuing evolution of chimpanzee, human and perhaps other older MSYs.

Chromosome Segregation

Towards building a chromosome segregation machine in Nature.
All organisms, from bacteria to humans, face the daunting task of replicating, packaging and segregating up to two metres (about 6 × 10^9 base pairs) of DNA when each cell divides. This task is carried out up to a trillion times during the development of a human from a single fertilized cell. The strategy by which DNA is replicated is now well understood. But when it comes to packaging and segregating a genome, the mechanisms are only beginning to be understood and are often as variable as the organisms in which they are studied.

Quantum Computers

Physics: Quantum computing in Nature.
The race is on to build a computer that exploits quantum mechanics. Such a machine could solve problems in physics, mathematics and cryptography that were once thought intractable, revolutionizing information technology and illuminating the foundations of physics. But when?

Martian Methane

Planetary science: A whiff of mystery on Mars in Nature.
Methane has been discovered in the Martian atmosphere. Could that be a sign of life?