Wednesday, March 19, 2014
Apozygotic agamospermic apomictic agamospory
I'm making a table. Not the tisch, bord, tavolo, mensa kind. I'm making a table of comparisons of offspring viability between sexually and asexually produced offspring. This is polychallenging. Part of it is that the literature is scattered, so it takes a lot of hunting around, but that is a usual and interesting sort of challenge. Part of it is that I want to include lots of different kinds of organisms, and find basically comparable comparisons for each, and the measure one might use for offspring viability for a lizard is necessarily different than that used for an insect, plant or mold, but this is arises from the real diversity of biological process, and so is also interesting. The part that I am finding frustrating and difficult is the choking miasma of obfuscatory terminology. Some terms, like amictic, are used to mean different things by different authors. Clear concepts (e.g., what portion of seeds open and something live comes out) are referred to by a dozen different terms. Frequently a single author or group of authors will have a term that does not seem to be defined anywhere and isn't used by anyone else. Apozygotic, for example, seems to be used only by eastern European sugar beet scientists to mean agamospermic, which is a term botanists use to describe reproduction via diplospory, apospory or nucellar embryony, which are all (I think) non-automictic kinds of agamospory, which is close to what a zoologist would call apomictic parthenogenesis, which basically means that offspring are coming out of eggs (or seeds or spores) produced without any genetic recombination or changes in chromosome number along the way. There are various places in the literature or on the web where good intentions have tried to straighten all of this out and discard the duplicate or ambiguous terms, but of course they come to different conclusions and are frequently ignored.