Today we'll feature some of the most interesting conversations we've had on our program's ‘One on One’ segments.   Curiosity Spots Ancient Streambed on Mars - Dawn Sumner from the University of California/Davis the Mars Science Laboratory team. Canadian scientists found that the effect humans have on ecosystems and the food chain has been greatly underestimated.  – Marco Musiani from the University of Calgary A study showed that there's been a ''pause'' in global warming over the past decade. - Alexander Otto, from Oxford University’s Environmental Change Institute A heavy bombardment of meteorites delivering an important chemicals may have kick-started life on Earth. - Matthew Pasek, from the University of South Florida