Sentences with phrase «hundreds of thousands to millions of years»

Over hundreds of thousands to millions of years, the change in gene frequency has altered the physical aspects of the species as a whole.

After each mass extinction, it took hundreds of thousands to millions of years for biodiversity to build back up to pre-crash levels.

Sedimentary rock layers provide a more compressed view of climate, as each layer of sediment is made over a period of hundreds of thousands to millions of years.

«Before the Lunar Reconnaissance Orbiter was launched in 2009, we thought that it took hundreds of thousands to millions of years to change the lunar surface layer significantly,» Speyerer said.

Even long - term climate cycles are short relative to geologic time, where «we're talking about hundreds of thousands to millions of years for plate tectonics,» Olive says.

«Isolating species has consequences — it can catalyze evolutionary change over hundreds of thousands to millions of years,» Behrensmeyer said, «but it also makes species more vulnerable to extinction.»

However, the Big Five occurred over periods of hundreds of thousands to millions of years, so Barnosky and colleagues also attempted to determine how long it might take us to reach mass extinction levels (75 % of species extinct).

The portions of Greenland not immediately adjacent to the ocean have been continuously covered in ice sheets for tens of thousands to hundreds of thousands to millions of years.

To answer this question, the scientists examined a hypothetical scenario in which the Big Five extinctions occurred suddenly, such that all of the species went extinct over just 500 years rather than over hundreds of thousands to millions of years.