His theory was that Martians were trying to bring water to the warm areas near the equator of the planet.

VOA: special.2010.07.11

Another theory says that the stress of having to pay constant attention to survive leads to Third Man hallucinations.

VOA: special.2010.02.24

Darwin had been working on his theory for over twenty years when he published " On the Origin of Species."

VOA: special.2009.12.01

Also,the broken windows theory did not fully investigate the exact conditions of disorders that appeared to lead to crime.

VOA: special.2009.03.03

One argument against the comet theory is that a comet would have left a large hole in the Earth's surface.

VOA: special.2009.01.20

The researchers had a theory. They thought that people who were bitten by infected mosquitoes,but recovered, were protected in the future.

VOA: special.2011.05.31

His theory of Martian life became so complex that he made maps of cities and waterways on the planet.

VOA: special.2010.07.11

The theory explains that as the sea floor spreads, the tectonic plates are pushed and pulled in different directions.

VOA: special.2011.01.04

In nineteen eighty-two, American researchers James Wilson and George Kelling wrote a report describing what they called the broken windows theory.

VOA: special.2009.03.03

And she explains the theory of evolution through natural selection in a way that both children and adults will enjoy.

VOA: special.2009.02.27

Studies support the theory that there are several causes, instead of a single environmental cause or genetic problem.

VOA: special.2009.01.06

The researchers had a theory. They thought that people who were bitten by infected mosquitoes, but recovered, were protected in the future.

VOA: special.2009.01.27

Charles Darwin developed the theory of how living things develop from simpler organisms over long periods of time.

VOA: special.2009.02.25

A separate study found no support for a theory that a biomarker called C-reactive protein causes heart disease.

VOA: special.2009.07.15