Glowing salamanders shed light on evolution

Hillary Maddin wanted to look inside the heads of animals as they grow to adulthood, so she found a unique method: Grafting glow-in-the-dark pieces into them when they are young.
Maddin is a paleontologist at Carleton University who was testing whether salamanders are primitive creatures similar to animal life many millions of years ago. (Short answer: No. More on that in a minute.)
She bought them from a breeder in Kentucky. 
The species is called a Mexican axolotl, and it’s normally