title: Commentary on: "A common origin for immunity and digestion".
authors.affiliation: Department of Physiological Sciences, Stellenbosch University Stellenbosch, South Africa.
authors.forename: Gustav
authors.initials: G
authors.lastname: van Niekerk
authors.affiliation: Department of Physiological Sciences, Stellenbosch University Stellenbosch, South Africa.
authors.forename: Anna-Mart
authors.initials: AM
authors.lastname: Engelbrecht
keywords: adaptive immune system; evolutionary constraint; immunological novelty; intestinal biota