Magazine

January-February 2011

Current Issue

January-February 2011

Volume: 99 Number: 1

DNA is an exotic polymer that measures on the atomic scale in one dimension (width) and the human scale in the other (length). Every human cell contains about two meters of DNA, almost all wound around proteins called histones to form nucleosomes. Nucleosomes group together to form higher levels of structure about which, after a hundred years of investigation, we still know very little. We do know that the DNA packs tightly in some chromosomal territories and loosely in others, forming sheer walls and intergenic fissures, as seen in the cover image from a 3D animation by renowned molecular animator Drew Berry. In "Chromatin Evolving," evolutionary biologist Gregory Babbitt reviews what we know and don't know about the higher-level structures formed by DNA, including how they are investigated, how they affect gene regulation and how they evolve.

In This Issue

  • Agriculture
  • Art
  • Astronomy
  • Biology
  • Chemistry
  • Communications
  • Computer
  • Economics
  • Engineering
  • Environment
  • Ethics
  • Evolution
  • Physics
  • Policy
  • Psychology
  • Sociology
  • Technology

Fractures and Bindings of Consciousness

Mark D. Holmes, Don M. Tucker

Biology Evolution

From Treasury Vault to the Manhattan Project

Bruce Cameron Reed

Physics Policy

The U.S. War Department borrowed 14,000 tons of government silver in its drive to make the world's first atomic bomb

Chromatin Evolving

Gregory Alan Babbitt

Biology Evolution

Despite our long familiarity with the chromosome, much about its function and evolution remains a mystery

Galaxies

Virginia Trimble, Harlow Shapley

Astronomy

An American Scientist classic article

Scientists' Nightstand

Departments