Dinosaur legs have been grown on chicken embryos in laboratory by scientists whose findings have been published in the journal Evolution. You might yourself want to leg it!
Dinosaurs are thought to have evolved into birds: following the mass destruction event that prompted their extinction, some of them survived, and were subject to evolutionary changes such that they turned into birds over the course of millions of years. What about the processes that happened in between? How has the gradual transition occurred?
Scientists are still working on drawing out the anatomical modifications that took dinosaurs to birds. To add to the bulk of work conducted for this purpose, a team of researchers have grown dinosaur legs in chicken embryos. They had also grown dinosaur-like feet on chickens in 2015. This might remind you of another study last year involving the growing of a dinosaur-like snout on a chicken.
Modern birds are claimed to have come from the group of dinosaurs known as coelurosaur (the Tyrannosaurus, for example, was part of this group). It is thought that the Coelurosauria developed into the Archaeopteryx, which later evolved into birds as we know them. The Archaeopteryx displayed a tube-shaped bone, the fibula, that extended till the ankle. The fibulae of modern-day birds, though, do not reach the ankle. This is the change that the scientists wanted to understand.
They inhibited the expression of the gene named ‘Indian Hedgehog’ (IHH) in the chicken. Following this, the dinosaur-like fibula was able to grow till the ankle. This deactivation was also associated with a greater activity of another bone-growth-related gene named PthrP which caused the fibulae to continue growing till the ankles. The scientists also found that this growth interruption happened when ankle bone calcaneum develops.
This finding shows that the fibulae of modern chickens are prevented from growing, a mechanism happening at the level of their genetics.
Oh, and lest you become worried about geneticists developing dinosaurs in laboratory, know that the scientists said that these dinosaur-like chickens were not hatched.