Michael Specter started working for The Washington Post in 1985 and became a staff writer with The New Yorker (cover is of the 3 December 2007 issue) in 1998. In between he worked in Europe for The New York Times.

'Darwin's Surprise' in this issue is about endogenous retroviruses which, Specter tells us, "infect the DNA of a species [and] become part of that species". Unlike regular viruses, retroviruses reverse the 'flow' of genetic code from DNA to RNA:

A retrovirus stores its genetic information in a single-stranded molecule of RNA, instead of the more common double-stranded DNA. When it infects a cell, the virus deploys a special enzyme, called reverse transcriptase, that enables it to copy itself and then paste its own genes into the new cell's DNA.

In this way, 'endogenous' retroviruses "alter our genetic structure" and it is a scientific fact that disabled retroviruses "make up eight per cent of the human genome".

Specter shows that the success of a species in one generation may cause it to be susceptible to a new retrovirus in a later age. In fact, the propeller-heads have shown this to be true. Our current problem with HIV is, they say, the result of our success in combatting another virus, called PtERV, four million years ago. Gorillas and chimps, who died in large numbers at that time due to this virus, are now immune to HIV.

But he goes further, noting, with gravitas conveyed by a researcher at the Institut Gustave Roussy, near Paris, Thierry Heidmann, that "without endogenous retroviruses mammals might never have developed a placenta, which protects the fetus and gives it time to mature";

That led to live birth, one of the hallmarks of our evolutionary success over birds, reptiles, and fish. Eggs cannot eliminate waste or draw the maternal nutrients required to develop the large brains that have made ammals so versatile.

Heidmann says that retroviruses, being "two things at once: genes and viruses", "helped make us who we are today just as surely as other genes did." It is a fascinating story.

Also in this issue is a piece, also long (in traditional New Yorker style), by Geraldine Brooks. It chronicles the entwined destinies of two families of Serbs, one Muslim and one Jewish.

It is a story of redemption and really is worth reading, although the odd-sounding names make it hard to follow at times. In it, a kindness given by a man in one generation, is returned in the next by a woman, and finally rewarded by the entire state of Isreal in the next. It ends in the mid-nineties when the war in that part of Europe was sizzling across our TV screens.

It is a war, as this story shows, for which the statute of limitations, in terms of the stories it may produce, is nowhere near ended. For this reason, we should study such authors as Dubravka Ugresic, whose experiences in Croatia during and after the period of turmoil, make good reading.