Monday, March 22, 2010

Arthropod Phylogeny

Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences in Nature.
The evolutionary interrelationships of arthropods has long been a matter of dispute. A new phylogeny applies an arsenal of techniques to more than 41,000 base pairs of DNA from 75 arthropod species. The results support the idea that insects are land–living crustaceans, that crustaceans comprise a diverse assemblage of at last three distinct arthropod types, and that myriapods (millipedes and centipedes) comprise the closest relatives of this great 'pancrustacean' group

See also Surprising New Branches on Arthropod Family Tree
The the newly defined sister group to the Hexapoda (insects and related species) is the Xenocarida or strange shrimp some unusual recently discovered marine crustaceans. So insects are actually more closely related to some oddball marine crustaceans than other terrestrial arthropods such as spiders.

High Energy Cosmic Rays

Cosmic-ray theory unravels in Nature.
Astrophysicists ponder whether ultrahigh-energy particles really do come from the centre of galaxies

Could they be iron nuclei instead of protons?

Pregnant fathers selective abortion

Evolutionary biology: Pregnant fathers in charge in Nature.
Pipefish and related species provide rare examples of extreme male parental care. Controlled breeding experiments allow the resulting conflicts of interest between female, male and offspring to be explored

The Golden Ratio found in a magnet

Solid-state physics: Golden ratio seen in a magnet
The golden ratio — an exact 'magic' number often claimed to be observed when taking ratios of distances in ancient and modern architecture, sculpture and painting — has been spotted in a magnetic compound

Sterile Neutrinos

Hunt for the sterile neutrino heats up in Nature.
Neutrinos like to keep to themselves. These ghostly particles are so reluctant to interact with ordinary matter that billions zip harmlessly through each person every day, and it takes giant, specialized detectors to capture even a handful of them. Now astronomers are finding hints of an even more elusive type of neutrino, one so shy that it could never be detected directly: the sterile neutrino