A neat example is sex, one of the most obvious and striking axes of biological variation. Unlike humans where the presence or absence of an entire chromosome (X or Y) determines sex, there are turtles and reptiles that determine their sex based on ambient temperature alone.
The logical consequence is that a pair of female and male turtle twins can share exactly the same genome yet be different sexes — their sex is determined solely by how their genome is read (epigenetics).
A neat example is sex, one of the most obvious and striking axes of biological variation. Unlike humans where the presence or absence of an entire chromosome (X or Y) determines sex, there are turtles and reptiles that determine their sex based on ambient temperature alone.
The logical consequence is that a pair of female and male turtle twins can share exactly the same genome yet be different sexes — their sex is determined solely by how their genome is read (epigenetics).