For most animals, reproduction is straight forward as some species lay eggs, while others give birth to young babies alive. But a study found out that an Australian species of lizard can apparently do both in the same pregnancy. However, scientists at the University of Sydney witnessed this in a three-toed skink, which layed three eggs and then later gave birth to a live baby. This was an event that had never been witnessed in any vertebrate species before.
However, this little lizard belongs to a rare group of species that are "bimodally reproductive" meaning that some of it's members lay eggs, while others give birth to their offspring live. Physiologically, this evolution from egg-laying to live birth is no mean feat as it requires a whole suite of changes such as the evolution of a placenta, new specialist body organ, loss of the hard outer eggshell and also ability of keeping embryos inside the body for a long period of time.
Although, it was not still clear on what was responsible for the triggering of female to lay eggs and give birth to a live baby from the same pregnancy but findings suggest that transition between egg-laying and live bearing may hedge bets reproductively before a true transition to live birth begins to evolve.
Content created and supplied by: Joebaby (via Opera News )