Making babies without daddies

Hey ladies—if only! There is a species of North American lizards that is entirely female. Thepropagates without males, through asexual reproduction. But unlike other living things that reproduce asexually, the New Mexico whiptail lizards produce genetically unique offspring. This is because they have double the chromosomes of their lizard relatives. Biologists don't understand how or why, but this bizarre adaptation eliminates the major problem with asexual reproduction. As we learned in Curio #80 and Curio #330 —both about the impending—asexual reproduction eliminates genetic variety, making organisms very susceptible to environmental dangers like disease or predators. But when New Mexico whiptailare created asexually, they still have to select among sister pairs of chromosomes. This preserves the whiptails', so offspring don't automatically inherit characteristics that spell their doom. Characteristics such as susceptibility to the Panama disease. That's the flaw currently wiping out the genetically defenseless seedless Cavendish banana. And while the New Mexico whiptails avoid the major pitfall of asexual reproduction, they benefit from the major benefit: mating with yourself is extremely efficient. There's a funny closing line here for sure, but may I remind we are running a family-friendly operation? So you'll have to provide your own giggles, kind of like the poor New Mexico whiptail.