|Cyanobacteria, such as this Anabaena,
are photosynthetic bacteria that came
about through the combination of
electron transfer chains from two
different sulfur bacteria through
horizontal gene transfer.
Photo by Elapied.
|The most common form of carpel in
flowering plants is like these in Eranthis,
appearing as leaves folded around
developing seeds (ovules).
|Early stamens may have
been flat and leaf-like,
as in this Degeneria
More recently, maize (or corn in America), Zea mays, originated rather suddenly through modification of just a few genes that controlled the location of the female flower spikes, and the nature of the seeds, in a wild plant called Teosinte.
In sum, through the tricks of horizontal gene transfer, endosymbiosis, hybridization, mutation in regulatory genes, and epigenetics, the evolution of photosynthetic organisms has periodically taken dramatic leaps forward.