A study has been done in which analysis of the evolutionary tree of the reptiles has been done. The study has been carried out by a group of researchers from George Washington University in Washington.

The journal Ecology Letters-published research has found that 175 million years ago, the ancestors of modern-day geckos and pythons used to give live births like humans. The trend has changed now as most snakes and lizards now lay eggs.

Alex Pyron, a biologist at the university was of the view that knowing that at that time species used to give live birth is not less than a shock. The research is supported by fossils of lizards from the Cretaceous period.

After studying the fossils, it has been found that there were embryos inside female lizards. This gives an idea that they used to give live births at that time. Around 10,000 species of lizards and snakes are alive today and out of them, around 8,000 lay eggs.

But rest of the 2,000 that give live birth are said to have adapted the ability recently. "Before, researchers long assumed that the ancestor of snakes and lizards laid eggs, and that if a species switched to live birth, it never reverted back. We found this wasn't the case", affirmed Pyron