Conclusion
We have tried to give a glimpse of the development of philosophy of biology since the “first wave” in the late 1960s and early 1970s, as well as some details about two areas of biological inquiry - systematics and selection - in which philosophers have had an active role in shaping the conceptual landscape.
We have also sketched a mounting problem in the foundations of the study of ecology and evolution, where there is interesting philosophical work to be done. We have not tried to survey the entire field, choosing instead to present miniature case studies of the kind of engagement with science that characterizes not only the best current work in philosophy of biology, but also first- and second-wave philosophy of biology. As the field develops into a widely recognized sub-specialization in philosophy of science, and it becomes possible to spend one's time responding to philosophers rather than to philosophers as well as biologists, it will be increasingly important to emphasize engagement with science and scientists.Having had a look at the past and present of philosophy of biology, one might ask what shape the fourth wave might take. The prospects are exciting. Because of the efforts of their progenitors, third-wave philosophers (and historians) of biology have found wider acceptance among their peers for work that is conducted collaboratively as well as for work that is conducted across disciplinary boundaries. Interdisciplinarity is not new in philosophy of science, of course, but the possibilities and opportunities are widening and may continue to do so. As more interdisciplinary groups and programs are formed, new avenues for intellectual work are opened, as are new channels of communication between scientists and philosophers. Philosophers have long been involved in cognitive science, evolutionary theory, and systematics, but as the case of ecology shows, there are other areas of biology in which there is work to be done that is both philosophically interesting and potentially of value to theorists in those areas.
These new possibilities for intellectual work are not limited to tackling conceptual problems faced by scientists. As it becomes accepted practice that philosophers should do part of their training in laboratories and in science courses, it also becomes clear that science can inform philosophy. Recent work on explanation is one example of this phenomenon. We inherited from philosophy of physics an account of explanation that did not obviously apply well to biology, as Hull (1974) and Wimsatt (1976) noticed a generation ago because they were deeply engaged in understanding science and its practice. Biological explanation and how it works is now one of the more lively topics of discussion in philosophy of science. Perhaps it is not too much to hope that as the fourth wave develops there will be continued interest in conceptual topics raised by scientists as well as in traditional issues in philosophy of science that are understood in new ways as the relevant science becomes a more prominent impetus for philosophical investigation.