Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology

notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations

Phorbol Ester-induced Myeloid Differentiation is Mediated by Protein Kinase C-Alpha and-Delta and not by Protein Kinase C-BetaII, -Epsilon, -Zeta, and -Eta.

It is generally accepted that the multiple, similar protein kinase C (PKC) isoq mes are responsible for different specialized physiol < gical processes, but evidence that directly assigns specific functions to specific isozymes is scarce. To test whether specific PKC isozymes are involved in myeloid differentiation, we have studied the effect of overexpression of PKC-a, -011, -6, -6, -( and -q in 32D, a mouse myeloid progenitor cell line that does not differentiate in response to 12-0-tetradecanoylphorbol-13-acetate (TPA). No significant morphological or phenotypic changes could be observed in unstimulated cells that overexpress any of these isozymes. However, the cell lines that overexpressed PKC-a or -6 had acquired the ability to become mature macrophages 2-6 h after TPA stimulation. The overexpression of PKC-BII, -6, -f, or -q, in contrast, did not permit TPA-induced differentiation. These results indicate that only these two members of the PKC gene family can participate in TPA-induced myeloid differentiatio