This mixed-methods study examined the interactions and learning outcomes of science teachers in an online graduate-level course on evolutionary biology intended to improve their content knowledge and science lesson planning. Discussion posts made by the teachers in this seven-week course were analyzed for cognitive presence using the Community of Inquiry framework. Compared to other studies examining cognitive presence, high levels of Integration level cognitive activity were observed (47% of total posts). This was most likely due to the design of the discussion prompts and expectations used to frame student participation. The questions were open-ended, and students were expected to use reference materials to construct their responses. During the course, 395 student posts contained statements that could be coded for scientific accuracy. Of these, 85% were coded as scientifically accurate. This reinforces reports from previous literature that the online environment is conducive to reflective and careful contributions by participants. As the course progressed, the number of faculty posts per discussion declined, while the number of student posts remained relatively constant. Student-to-student posts increased in frequency as faculty participation dropped. The number of student posts increased towards the end of each two-week discussion period, however the frequencies of posts with scientifically accurate statements and Integration level cognitive activity remained relatively constant over this same period. The increase in total posts was due to the increase in other types of communication in the discussions. Case study analysis was used to examine patterns of online behavior in three participants who achieved different course grades. A low-performing student had a pattern of intermittent activity, made low numbers of posts in each discussion, and had low percentages of posts that contained scientific statements or indicators of Integration level cognitive activity compared to classmates. A medium-performing learner posted infrequently but was efficient in making scientifically accurate posts that demonstrated Integration. Both the medium and low performer made most of their posts near the end of each two-week discussion period and had limited interaction with other learners. The high-performing learner demonstrated high levels of engagement with the course material. She posted frequently, introduced new resources to the other learners, and had high numbers of scientifically accurate and Integration level posts. An examination of teachers' views of the Nature of Science (NOS) using a pre- and post course Views of Nature of Science--C survey indicated that this group of teachers began the course with relatively informed views of many of the nature of science aspects. An exception was views about the nature of scientific theories and laws. At the start of the course 10 of 18 participants had naive views, five had partially informed views, and three had informed views. While scientific definitions of theories and laws were addressed in the course, there was no task that asked teachers to apply their understanding of this topic. When the course finished, six participants still had naive views, six held partially informed views, and six had informed views. Participants used course content to create teaching unit plans that indicated how they might use the course outcomes in their practice. Most of the learning objectives stated in the unit plans were grade-level appropriate when referenced to the Benchmarks for Science Literacy. The exception was the inclusion by some middle school teachers of detailed analyses of evolutionary relationships using genetic data. Although there was alignment of stated objectives to content from the online course and lesson activities, some of the teachers did not fully align assessments with their objectives. Based on these findings, it is suggested that designers of online instruction be mindful in the framing of learning tasks and use open-ended discussion prompts that require the use of reference materials if Integration level cognitive activity is the goal. The teachers in this course were generally able to utilize content from the course to create teaching applications, but more support for pedagogical applications could be an important addition for teachers who struggled with this task. This study reinforces previous research that indicates that online asynchronous discussions encourage reflection by learners. However, analysis of individuals who struggled in the course indicates that the online format may not suit all learners since consistent effort and the ability to communicate effectively in writing are important for success. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]