In this video collaboration from Khan Academy and 23andMe, you'll learn how chromosomes and genes are passed down from parent to child.

In this video collaboration from Khan Academy and 23andMe, you'll learn how your observable traits, or phenotypes, are the result of interactions between your genes and environment.

In this video collaboration from Khan Academy and 23andMe, you'll learn how your observable traits, or phenotypes, are the result of interactions between your genes and environment.

In this video collaboration from Khan Academy and 23andMe, you'll find out why women don't have a Y chromosome. Even with no Y, women can still learn about their paternal ancestry with genetic testing from services like 23andMe.

Final video in a series from 23andMe and Khan Academy that introduces human prehistory, this video describes how when people started crossing oceans, genetic and cultural differences between people from different continents began fading.

Second in a series of videos from Khan Academy and 23andMe, this video introduces human prehistory, this video describes how our human ancestors spread throughout Africa and then into other regions such as Australia and Europe. How did they reach Australia so early on? What happened when our ancestors encountered Neanderthals?

Third in a series of videos from Khan Academy and 23andMe that introduces human prehistory, this video describes how early humans continued to defy the odds and populated the Americas during the last ice age.

Fourth in a series of videos from Khan Academy and 23andMe that introduces human prehistory, this video describes how agriculture changed human societies and genetics throughout the world.

This award-winning video collaboration from Khan Academy and 23andMe introduces human prehistory starting over 200,000 years ago. Who were our first human ancestors? Where did they live?

oerc-1844 Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.