Last time, I criticized Ann Gauger’s Evolution News and Views article “A Simple Transition to Multicellularity — Not!” for asserting that the requirement for kinesins in Volvox inversion implied a requirement for novel genes in the evolution of multicellularity. In a similar vein, Dr. Gauger presents programmed cell death and sex as problems for this transition:
The somatic cells commit suicide by a process known as apoptosis — programmed cell death — that I wrote about here. This process involves a minimum of several novel genes as well.
Where does this assertion that programmed cell death in Volvox “involves a minimum of several novel genes” come from? Programmed cell death (PCD) occurs in many unicellular eukaryotes, including Chlamydomonas reinhardtii. Furthermore, two types of metacaspases, genes involved in PCD in many algae and plants, are found in both Chlamydomonas and Volvox.