Unraveling the Ancient Mystery: What Came First, Chicken or Egg?

The age-old question of whether the chicken or the egg came first has long puzzled both scholars and schoolchildren. However, scientists may have finally unravelled the mystery.

Scientists from the University of Bristol and Nanjing University have made a groundbreaking discovery regarding the evolution of birds and reptiles. Contrary to the prevailing belief that hard-shelled eggs were crucial to the success of these species, the researchers propose that their early ancestors gave birth to live young instead.

The findings, published in the Journal Nature Ecology and Evolution, challenge the long-held notion that amniotic eggs were essential for the development of amniotes. The study analyzed 51 fossil species and 29 living species, revealing that all branches of Amniota, including mammals, retained embryos within their bodies for extended periods. This extended embryo retention likely provided the animals with ultimate protection.

Professor Michael Benton of the University of Bristol remarked that this research dismisses the traditional “reptile egg” model, highlighting the significance of extended embryo retention for these organisms.

Furthermore, the study found that live-bearing lizards can easily switch back to laying eggs, suggesting flexibility in their reproductive behaviours.

In light of this study, it can be said that the ability to give birth to live young may have preceded the development of hard-shelled eggs. However, it is important to note that the specific order of events in the evolutionary timeline is still a subject of ongoing scientific investigation and debate.