Life Sciences and Chemistry

In news that will surely fan the flames of the heated debate over genetically modified crops, scientists have found evidence that genes from GM plants can spread far and wide to native ones. According to a report published today in the journal Nature, wild corn from the remote mountains of Oaxaca, Mexico contains transgenic DNA. This, the researchers note, bolsters concerns that such unintentional contamination can threaten the genetic diversity of natural crops.

DNA analyses of the Oaxaca

Rewiring the egg: mechanism remains murky.

From a scientific viewpoint, the cloning of human embryos may be more of a step than a leap, say sceptics. If the signals that turn adult cells into embryonic ones can be found, the creation of cloned embryos for tissue repair may become redundant.

Researchers at Advanced Cell Technology (ACT) in Worcester, Massachusetts, now report that they have created cloned human embryos. They aimed to make blastocysts, hollow balls of cells fr

The size and types of the largest local land animals vary greatly from place to place, prompting scientists to question what controls the success of animals of certain sizes over others. Now a report published in the current issue of the Proceedings of the National Academy of Sciences shows that the size of a landmass limits the maximal body size of its top animal.

Gary Burness and Jared Diamond of the University of California School of Medicine, together with Timothy Flannery of the South

New research is helping to unravel the machinery that allows a mosquito to sniff out its human quarry, which could lead to more and better ways of foiling the disease-spreading insects. A report published today in the online version of the Proceedings of the National Academy of Sciences describes four genes that appear to produce odor-sensing molecules in Africa’s Anopheles gambiae, a carrier of malaria, the number two killer in the developing world. Understanding how such genes operate could en

Talk about multi-tasking. A new study reveals that in the St. John’s Wort plant, Hypericum calycinum, the same chemical not only attracts pollinating insects but also deters herbivores that pose a threat to its survival. The findings appear in the current issue of the Proceedings of the National Academy of Sciences.

To the human eye, the flowers of H. calycinum appear as uniform yellow disks (top image). Insects with ultraviolet-sensitive eyes, however, see a dark, ultraviolet-absorbing ce

Evolution may make men ignorant and gullible.

Gentlemen: ignorance is bliss and gullibility is the best policy. A new mathematical analysis suggests that evolution favours babies who don’t much resemble their fathers, and males who believe their partner when she says a child looks just like him.

Anonymous-looking newborns make for uncertain fathers. But they also allow men to father children through undetected adultery, Paola Bressan of the University of Padova calculates