Cladogram of ascidians. This figure shows the transitional states predicted by Gilbert’s (2015) historical model (Fig. 6). Cladogram is organized by suborders A Phlebobranchia, B Aplousobranchia, C Stolidobranchia, and the form of histocompatibility (fusion-rejection) behavior employed (see Appendix for methods).

  Part of: Gilbert OM (2020) Natural reward drives the advancement of life. Rethinking Ecology 5: 1-35.