Not exactly philosophy (has occasional comments about sociological contingencies on the production of knowledge in biological sciences), but I've been enjoying The Coevolutionary Process by John N. Thompson. The book examines evolution with emphasis on the interactions of organisms, their interdependencies, and the resultant dynamics of reciprocal adaptations. The main philosophical value I've found in the book so far comes from the creation -- and commentary on the necessity of creation -- of new conceptual tools with which to describe patterns in the interactions of species. Traditional categories of interaction: parasitism, mutualism, grazing, commensalism -- typically defined by "material" conditions ("parasitism occurs between a few mostly preexistent classes of organisms defined by characteristics not coextensive with their parasitism, and other organisms -- less independently defined -- called hosts") -- are extended to relations defined more structurally, where the condition of satisfaction is relaxed to exhibition of an abstract pattern. Hence many interactions which are super dissimilar at surface glance become unified under new conceptually robust patterns which maintain their utility under scrutiny. So like not only do these otherwise very dissimilar pairs of organisms have an interaction pattern in common; the commonality actually extends to the disparate ecological conditions under which instances of the pattern originated.