These were not swift, massive die-out's of the kind that famously wiped out the dinosaurs 65 million years ago, but rather a fadeout of species which could not cope with habitat loss or competition, especially when Ice Ages kicked in.
As they became extinct, other species emerged.
"At any given time, there would be around 15 (rodent) species in residence," van Dam said. "During the extinction waves, about five or six species would disappear over a period of about 100,000 years or so."
The paper, which appears on Thursday in the British journal Nature, is confident that the species turnover among rodents also happened to other mammals and possibly other biological groups too.
Astronomical impact "provides a crucial missing piece in the puzzle" of regular species turnover, it says.
Previous research has also established that Earth's climate system can be affected by massive volcanic eruptions or the impact of an asteroid or comet. These can kick up so much dust that the planet receives less sunlight, and in turn plant species suffer.
In addition to natural factors, the world's climate system and its biodiversity are also being affected by the burning of fossil fuels.
Oil, gas and coal, and to a lesser degree agriculture, release carbon gases into the atmosphere, creating a "greenhouse effect" that traps solar radiation and causes Earth's surface temperature to warm.
