Learn about common ancestors shared by every human; evolution’s multiple directions; and universal facial expressions.

There's a point in the past when every person on Earth was an ancestor to every person alive today by Grant Currin

• Hershberger, S. (2020, October 5). Humans Are All More Closely Related Than We Commonly Think. Scientific American. https://www.scientificamerican.com/article/humans-are-all-more-closely-related-than-we-commonly-think/
• Hopkin, M. (2004). Human populations are tightly interwoven. Nature. https://doi.org/10.1038/news040927-10
• Numberphile. (2019). EVERY baby is a ROYAL baby - Numberphile [YouTube Video]. In YouTube. https://www.youtube.com/watch?v=Fm0hOex4psA
• Rohde, D. L. T., Olson, S., & Chang, J. T. (2004). Modelling the recent common ancestry of all living humans. Nature, 431(7008), 562–566. https://doi.org/10.1038/nature02842

Evolution Doesn’t Have Just One Direction by Ashley Hamer

• Is the human race evolving or devolving? (1998, July 20). Scientific American. https://www.scientificamerican.com/article/is-the-human-race-evolvin/
• Waimanu, the first penguin. (2010, January 30). March of the Fossil Penguins; March of the Fossil Penguins. https://fossilpenguins.wordpress.com/2010/01/30/waimanu-the-first-penguin/
• Morber, J. (2016, October 6). 5 Times Evolution Ran in “Reverse.” Science; National Geographic. https://www.nationalgeographic.com/science/article/reverse-evolution-explained-hagfish-penguins-snakes-science?loggedin=true
• Elliott, K. H., Ricklefs, R. E., Gaston, A. J., Hatch, S. A., Speakman, J. R., & Davoren, G. K. (2013). High flight costs, but low dive costs, in auks support the biomechanical hypothesis for flightlessness in penguins. Proceedings of the National Academy of Sciences, 110(23), 9380–9384. https://doi.org/10.1073/pnas.1304838110
• How Birds Lost Their Teeth. (2014, December 12). Audubon. https://www.audubon.org/news/how-birds-lost-their-teeth
• The evolution of whales. (2021). Berkeley.edu. https://evolution.berkeley.edu/evolibrary/article/evograms_03
• How did whales lose their hind legs? - Popular Mechanics. (2006, May 23). Popular Mechanics. https://www.popularmechanics.co.za/science/null-610/

Are facial expressions universal? by Ashley Hamer (Listener question from Jared in Vancouver)

• Price, M. (2016, October 17). Facial expressions—including fear—may not be as universal as we thought. Science | AAAS. https://www.sciencemag.org/news/2016/10/facial-expressions-including-fear-may-not-be-universal-we-thought
• Ekman, P., & Friesen, W. V. (1971). Constants across cultures in the face and emotion. Journal of Personality and Social Psychology, 17(2), 124–129. https://doi.org/10.1037/h0030377
• Crivelli, C., Russell, J. A., Jarillo, S., & Fernández-Dols, J.-M. (2016). The fear gasping face as a threat display in a Melanesian society. Proceedings of the National Academy of Sciences, 113(44), 12403–12407. https://doi.org/10.1073/pnas.1611622113
• Krys, K., Melanie Vauclair, C., et. al. (2015). Be Careful Where You Smile: Culture Shapes Judgments of Intelligence and Honesty of Smiling Individuals. Journal of Nonverbal Behavior, 40(2), 101–116. https://doi.org/10.1007/s10919-015-0226-4

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