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

Polymeric and monomeric IgA response in serum and milk after parenteral cholera and oral typhoid vaccination

The effect of vaccinating lactating Pakistani mothers with a combination of live oral typhoid vaccine and parenteral inactivated cholera vaccine on specific milk and serum IgA antibodies in both monomeric (m) and polymeric (p) forms was analysed. IgA antibody titres peaked for both antigenic specificities 2 weeks after the first dose of vaccine. 82±7% of anti-Vibrio cholerae and 72±17% of anti-Salmonella typhi IgA were in the polymeric form. These serum pIgA antibodies were mainly dimeric IgA, not complexed with the secretory component. They disappeared more rapidly from serum than mIgA antibodies. Anti-V. cholerae IgA responses were parallel in serum and milk samples, whereas anti-S. typhi responses were dissociated. In milk, IgA antibodies were secretory IgA for both antigenic specificities, being probably of local origin in the mammary gland. Our results indicate that both oral and parenteral vaccinations can induce pIgA antibodies in serum and secretions, confirming that the presence of pIgA in serum does not necessarily reflect an immune stimulation only at the mucosal level.SCOPUS: ar.jFLWNAinfo:eu-repo/semantics/publishe