Bacteria usually reproduce asexually, though exchange of genetic material between individuals can be achieved through conjugation. Most plant species are hermaphrodites. Certain species of plant, insect, fish and reptile are parthenogenic, having done away with the male sex and the presumed benefits of sexual reproduction.
Some fish undergo sex conversions, depending in part upon their place in a social heirachy.
Nature conspires in elaborate ways to dispell our elementary textbook notion of sexual reproduction and the genetic basis for it. Temperature-depenent sex determination in reptiles is but another example. The influence temperature has on the outcome of sexual differentiation in reptiles was first noticed by Charnier in 1966. He found that eggs of the lizard Agama agama incubated at 26-27 o C in wet sand produced only females whereas eggs incubated on moist cotton at 29 o C produced mostly males. His work was largely ignored, partly because he published in French in a obscure journal produced by the Society of Biology of West Africa, and partly because his finding were so at odds with prevailing views on the mechanisms of sex determination in tetrapod vertebrates.