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The better half?

Klaus Esterluss
October 11, 2017

Some animal species can do very well without male partners. Mourning geckos are just one of many examples. Their reproduction method — known as parthenogenesis — is our natural phenomenon of the week.

Jungferngecko Lepidodactylus lugubris
Image: picture-alliance/Hippocampus-Bildarchiv

More or less once every two to four weeks over her five-year lifespan, the female mourning gecko goes through the same ritual: The reptile begins the search for a well-protected place to hide one or two of her eggs. Fifty to 75 days later, new geckos hatch from these eggs. Not very spectacular, right?

Jungferngecko Lepidodactylus lugubris
Image: picture-alliance/Hippocampus-Bildarchiv

But the nocturnal climbers look exactly like their mother. And if they lay egg, once they reach maturity after eight months, their offspring will look exactly like them. That's because mourning geckos clone themselves — and all of them are female. No males are required to reproduce.

A completely normal phenomenon

That reptiles do not need males is not totally unusual in nature and various other species do the same. Some crabs, snails, and plants as well as komodo dragons and single-celled organisms — all of them come into the world alive and well without a male. The process behind this is called parthenogenesis which means something like "virgin birth."

Being born in this way is possible because nature is pretty clever and has even produced different methods of parthenogenesis. In one process, hormones pretend that an unfertilized egg cell has been fertilized, kicking off development. Another method involves the existence of two sets of chromosomes in an egg, both of which have the same origin. In this case — and this also applies to the mourning gecko — a clone, a direct copy of the mother, is born.

A method to fail?

This kind of reproduction has advantages and disadvantages for the geckos. First and foremost, it is very practical because all offspring are females and therefore every specimen can reproduce. That means the geckos can spread quickly and easily. In addition, nobody has to put in much effort or worry about the stressful search for a romantic partner.

But it's not all sunshine and roses. If a disease or mutation creeps into the genetic material, then all the affected animal's clone-offspring will have that disease or mutation. If it is fatal, the entire population would quickly face extinction.

In sexual reproduction, this risk does not exist because both parents contribute different genetic information and the gene-pack reshuffles with each new offspring.

The stickiness of gecko feet

Animal Adhesion - Imitating the Stickiness of Geckos without Glue # 02.01.2012 # Tomorrow Today