WIKIed Biology is a National Science Foundation Transforming Undergraduate Education in Science, Technology, Engineering, and Mathematics interdisciplinary project in which the authors developed and implemented a model for student centered, inquiry-driven instruction using Web 2.0 technologies to increase inquiry and conceptual understanding in biology. Web 2.0 applications enhance collaboration among users to find, create, manipulate, and disseminate information and can form a relevant connection between real-world science and students' learning of content. Students use Web 2.0 technologies in their daily lives; however, there is little empirical research into its impact on student learning. This paper describes a course in which Web 2.0 tools (del.i.cious, CiteULike, and Google docs and sites) were used to support the teaching--learning process, including the use of tagging and social bookmarking, academic resource management, and website collaboration and design. Students reported gains in understanding of the relationship between the science process, Web 2.0 technologies, and scientific communication, as well as skill in evaluating validity of sources from the internet. Critical Thinking Assessment Tests supported these data.