* Rats found to understand cause and effect:
The discovery contradicts common assumptions among scientists, according to researchers.
* Sex, cleaner of genomes:
Sometimes, evolution needs a little help erasing harmful mutations. Sex may come to the rescue, a study has found.
* Study: stock market acts oddly before a crash
Before and after crashes, stock prices behave in some ways like heartbeats and earthquakes, physicists have found.
* Study: complex decisions best left to your unconscious:
It may be best to forget about a decision temporarily before making it, scientists say.
* Next dinosaur news likely to come from small packages:
Dinosaurs seem bigger than life. But the next big answers about them may come from tiny remains, scientists predict.