Earth's wobbly orbit blamed for mass mammal extinctions

Scientists have named a prime suspect in the mysterious case of the missing mammals. The reason history is littered with suspiciously regular extinctions is all down to the Earth's wobbly orbit, according to research published today.

Apart from mass extinctions caused by asteroids thumping into the planet and other cataclysmic natural events, records reveal that mammal species die out anyway, usually 2.5m years after they first emerge ... Guardian Unlimited | Science