More than two and a half billion years ago, Earth differed greatly from our modern environment, specifically in respect to the composition of gases in the atmosphere and the nature of the life forms inhabiting its surface. While today's atmosphere consists of about 21 percent oxygen, the ancient atmosphere contained almost no oxygen. Life was limited to unicellular organisms. The complex eukaryotic life we are familiar with – animals, including humans – was not possible in an environment devoid of oxygen.

In prehistoric times farmers across the world domesticated wild plants to create an agricultural revolution. As a result the ancestral plants have been lost, causing problems for anyone studying the domestication process of modern-day varieties, but that might change. A team led by Fabiola Parra at the Universidad Nacional Autónoma de México (UNAM) has managed to trace a domesticated cactus, the Gray Ghost Organ Pipe (Stenocereus pruinosus) to its living ancestor that can still be found in the Tehuacán Valley in Mexico. The research is published in the September 2010 edition of the Annals of Botany at http://aob.oxfordjournals.org/cgi/content/abstract/106/3/483

A microscopic look into the genes of a Colorado wheat variety has allowed Texas AgriLife Research scientists to identify a wheat streak mosaic virus-resistance gene.

Studies of the spinal fluid of patients given anti-HIV drugs have resulted in new findings suggesting that the brain can act as a hiding place for the HIV virus. Around 10% of patients showed traces of the virus in their spinal fluid but not in their blood – a larger proportion than previously realised, reveals a thesis from the University of Gothenburg, Sweden.