Online resources
Organizations promoting scientific understanding
The mission of the National Center for Science Education is to defend the teaching of evolution in public schools. They are a great source for news about evolution-related events and policies.
The National Science Teachers Association also promotes the teaching of evolution in public schools and provides useful evolution FAQ and resources for teachers on their evolution resources page.
Pennsylvania Citizens for Science is a local organization dedicated to protecting the teaching of science in schools. Their site provides blog-stype updates on local and national events and resources for Pennsylvanians looking to support the teaching of evolution.
The newly-formed Scientists and Engineers for America is a group dedicated to electing public officials who understand the importance of considering scientific evidence when making public policy.
Science authorities
The National Academy of Science is the most established scientific authority in the United States and provides resources to the U.S. government and the American public. The Academy elects scientists into membership who have made significant and esteemed contributions to research. Their Evolution Resources page provides links to resources produced or advocated by the Academy.
Websites providing good evolution tutorials
The Understanding Evolution site hosted by the University of California, Berkeley is a comprehensive resource that covers everything this site attempts, and more. Here you’ll find basic explanations of evolutionary biology, discussions on the the evolution “controversy” and resources for teachers.
PBS has created a television series on evolution, available here online, along with other multimedia resources and online lessons for teachers and students.
The ever-useful Wikipedia provides some handy and informative coverage of evolution and Charles Darwin.
Science-based sites addressing the evolution / creationism conflict
The Panda’s Thumb is a community blog-style site dedicated to discussing evolutionary biology and critiquing the anti-evolution movement.
The Talk.Origins Archive is a collection of essays and articles, most of which originated in the Talk.Origins Usenet newsgroup, which is dedicated to discussing the evolution/creationism controversy from a mainstream science perspective. It also provides an extraordinary list of evolution-related websites.
Dr. Kenneth Miller, a professor of biology at Brown University, has been one of the most vocal scientists in defending the integrity of evolutionary biology and in debating anti-evolution advocates. His site publishes many of his essays and debates.
Organizations challenging evolution
The Discovery Institute is a well-funded not-for-profit organization that promotes conservative Christian values, including an anti-evolution agenda. The Center for Science and Culture is a division of the Institute that has been influential in advocating intelligent design.
Answers in Genesis is a Christian ministry that actively promotes young-earth creationism. They publish the online Answers Research Journal, which produces articles reporting “science research” within a biblical framework.
Here is a list of anti-evolution and creationist websites that will make your head swim, provided by the Talk.Origins Archive.