Biology
Maternal Effects on Offspring Phenotype in Oviparous Reptiles
Quick fact
In some oviparous reptiles, females can adjust the amount of yolk or hormones they allocate to eggs, and the temperature of the nest they choose can determine the sex of their offspring—allowing mothers to influence offspring traits before hatching, beyond just DNA.
Why this is interesting
A mother lizard can alter her offspring's size, speed, and even sex without changing a single gene. How?