Homeotic Sexual Translocations and the Origin of Maize (Zea Mays, Poaceae): A New look at an old problem

摘要: In the Origin of Maize Controversy, Orthodox Teosinte Hypothesis (OTH; Beadle 1939, 1972; Iltis 1971), five key mutations change 2-ranked (distichous) ears teosinte (wild Zea) with a single row grains per rank to 4- many-ranked (polystichous) maize double rank. BUT are lateral 1° branch axes, ears, like their male homologues, I° tassel spikes, terminal, an enigma long unrecognized, hence ignored. Catastrophic Sexual Transmutation Theory (CSTT; 1983b, 1987), now abandoned, (male) (spikelets soft-glumed, paired, i.e., double-rowed rank, as in ears), when brought under female hormonal control by condensation, becomes feminized into proto-ear. should then have remained teosintoid (2-ranked, each grains), yet fact double-rowed. Combining OTH and CSTT, new Translocation (STLT) is based on: first, branching pattern ear clusters (Camara-H. & Gambino 1990), sequentially maturing, sympodially branching, typically Andropogonoid systems, called rhipidia (sing, rhipidium), where higher order (younger) originates its lower order, earlier maturing predecessor; second, on 3 or 4 [cupule reduction, softening glumes, doubling spikelets], which, projecting outward grains, invited human domestication making them accessible. Within cluster, earliest nutrient-monopolizing largest would be selected, all younger already nutrientinhibited, suppressed. As fewer, larger evolved, internode condensation moved tassels zones, homeotic conversions translocated morphology terminal positions: first replacing II° tassels, ultimately (male), (female). With this, structure apically dominant, most nutrient-demanding position gradually suppressing subsidiary beneath it, for polystichy (contingent nutrient overload) were finally allowed become expressed, multi-rowed (at atavistic tail) evolved. Favored selection, these increases apical dominance stepwise sexual explain both archeological morphological realities, but need harmonized recent results developmental genetics. Current evidence suggests that was tended green sugary pith hunter-gatherers occasional rainy-season food small “garden” populations away from homeland, not abundant grain-containing, hard fruitcases, which easily mass-collected useless food, unknown record. A rare grain-liberating mutation (probably expressed only one “founder” plant, mazoid “Eve”), exposed encased grain easy harvest, soon recognized useful, collected planted (or self-planted). Thus started way unique horticultural comparable temperate Old World mass-selected agricultural grains.