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Stem Cell Breakthrough Questions

Stem cell breakthrough withdrawn; Elephants are able to differentiate between human ethnicities and genders; Wet climate may have boosted the expansion of the Mongolian Empire

The future of regenerative medicine is pinned on stem cells, which can transform into any other type of tissue. So far, stem cells could only be gained through complicated and costly methods. In January, a study, published in the journal Nature, became a huge story that reported dipping cells in acid could cheaply and quickly convert them into stem cells. Meanwhile, controversies about the findings have arisen and study author Professor Teruhiko Wakayama proposed to withdraw the research paper. The BBC’s science and health reporter James Gallagher joins us with the details.

Elephants Recognise Human Voices
Elephants in eastern Africa regularly come into conflict with livestock-herding Masai people. A PNAS study suggests the animals are trying to adapt to this threat. Researchers played different human voice recordings to elephants and observed their reactions. They responded more fearfully to the voice of a Masai man, than to those of a Kamba man who pursue an agricultural lifestyle. The reactions triggered by voices of women and boys were also less defensive. Lead researcher Professor Karen McComb concludes that the animals can differentiate human ethnicities, gender and age.

Climate and Mongol Conquests
Eight hundred years ago, small armies of mounted warriors led by Genghis Khan suddenly left the cold, arid grasslands of Mongolia, and conquered the largest contiguous empire in history. How did they do it? A new study suggests that climate change played a role. Scientists used pine tree rings to reconstruct water availability during the last 1,100-years. The rings reveal an unusually wet period during the time of the Mongolian expansion. This could have resulted in a boom of grass production, providing Khan’s empire with lush resources to support a culture based on horses and cattle. Professor Neil Pederson from the Tree Ring Lab at Columbia University explains the details.

(Photo caption: Working on stem cells © Getty Images)

Presenter: Jon Stewart
Producer: Ania Lichtarowicz, Lennart Pyritz

Available now

18 minutes


  • Controversial Stem Cell Study

    Japanese author wants to withdraw his own publication.

    Duration: 05:34

  • Elephants Recognise Human Voices

    Elephants are able to differentiate between human ethnicities and genders.

    Duration: 05:14

  • Climate and Mongol Conquests

    Wet climate may have boosted the expansion of the Mongolian Empire under Genghis Khan.

    Duration: 06:06