
Hank guides us through the process of natural selection, the key mechanism of evolution. Crash Course Biology is now available on DVD! http://dftba.com/product/1av/CrashCourse-Biology-The-Complete-Series-DVD-Set Like CrashCourse on Facebook: http://www.facebook.com/YouTubeCrashCourse Follow CrashCourse on Twitter:... Read more »

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Hank takes us through the bowels of the human digestive system and explains why it’s all about surface area. Crash Course Biology is now available on DVD! http://dft.ba/-8bCC Like Crash Course? http://www.facebook.com/youtubecrashcourse... Read more »

The early 1900s was an amazing time for Western science, as Albert Einstein was developing his theories of relativity and psychology was born, as Sigmund Freud and psychoanalysis took over the scientific... Read more »