Darwin's observations showed him that environments can change a little very quickly and a great deal over time.

VOA: special.2009.02.27

Rosalyn Schanzer brings to life the clues that suggested to Darwin that living things evolve, or change,over time.

VOA: special.2009.02.27

But they say the land formation continues to change slowly over time.

VOA: special.2009.04.15

Katrin Verclas says she hopes FAILFaire will change this problem over time.

VOA: special.2010.09.13

Some genes change or disappear over time.

VOA: special.2010.02.02

"Because it's happening so quickly, they haven't had time to adapt and change, if you imagine a climate changing over hundreds of thousands of years, bears and other animals would gradually move into other habitats,but because this is going to happen over decades, it will be too fast for them to adapt and look for other food sources,"

VOA: standard.2009.12.13