I know Iâve let Friday Science entries slide lately. I just havenât had the time or energy to do any research. Thatâs why todayâs entry is brought to you by the letter R, which stands for Robin who sent me the link. You know that scene in Jurassic Park where they find all the dinosaur eggs and whatâs-his-name has to explain how female amphibians can âturnâ? male in predominately female environments? Todayâs entry is kind of like that. Researchers have found that sharks can reproduce asexually.
The investigation all started when a female hammerhead shark was born at the Omahaâs Henry Doorly Zoo. What was so mysterious about the birth was that is happened in a tank that only contained female sharks. Sort of like a shark version of Jerry Springer, âwhoâs my babyâs daddy?â?. The research team determined that the genetic makeup of the baby shark perfectly matched one of the females in the tank, but without any sign of a male parent.
The process is called parthenogenesis and happens when a byproduct called a sister polar body (formed when eggs are produced) fuses with an unfertilized egg. This occurs naturally in some species like plants, vertebrates such as aphids, and vertebrates like reptiles and fish. Parthenogenesis is a form of animal cloning because the new organism is identical to the cell donor. This process also decreases genetic variability which could be problem over time putting offspring at a genetic disadvantage.
Parthenogenesis is a testament to the resourcefulness of animals like sharks and reptiles. Mammals canât reproduce asexuallyâ¦yet.