This video was filmed on November 11, 2011 as part of the National Geographic Live! Lecture series at National Geographic Society headquarters in Washington, D.C.


Nobel Laureate Martin Chalfie and National Geographic Emerging Explorer Beth Shapiro discuss why only certain species survive and how a growing knowledge of genomes reveals a deeper understanding of life's cycles and secrets. Beth Shapiro travels through time— observing mammoths, dodos, and other extinct animals; witnessing the last ice age and arrival of humans in North America; watching genetic diversity shrink in one species while blossoming in another. As a molecular biologist, her journey is made possible by ancient DNA samples and statistical models that give science a new view of our tumultuous past.


Martin Chalfie shared the 2008 Nobel Prize in Chemistry with Osamu Shimomura and Roger Y. Tsien for the discovery and development of the green florescent protein, GFP. Leading the discussion is Boyd Matson, host of National Geographic Weekend.


  • A common ancester (start-1:00 min.)
  • Polar bear/brown bear hybrids: overlapping ranges (1:01-1:33 min.)
  • Irish brown bears (1:34-1:49 min.)
  • The future of polar bears (1:50 -3:04 min.)


Strategies for Using Video in a Variety of Learning Environments

  • Have students preview several of the videos and choose the one they find most inspiring. Have students describe in writing a conversation they might have with the speaker(s).
  • Freeze the video on a relevant image. Have students observe details in the still image and jot down predictions of what the full video might address. Discuss students’ ideas before and after watching the video.
  • Pose an open-ended question before students watch the video, and have them discuss their ideas before and after in small groups.
  • Have students determine what they think the key message of this video is. Was the speaker effective in getting his or her message across?
  • Show a short clip to engage students during class, and then have students watch the full video at home and write a paragraph responding to the content or a question you give them.
  • Have students note statements that represent facts or opinions, including where it’s difficult to tell the difference. What further research might help distinguish facts and opinions? How might the speaker’s viewpoint compare with others’ viewpoints about a topic?



the study of heredity, or how characteristics are passed down from one generation to the next.


the end result of two different sources of input.

polar bear

large mammal native to the Arctic.


native, geographic area in which an organism can be found. Range also refers to the geographic distribution of a particular species.