"What we have found is a major step toward understanding the age old question of sex determination."

Environmental sex determination is known to occur in a variety of species.

"The system of sex determination is turning out to be a lot more complicated than I was taught in medical school."

As a result of sex determination, the organism is either male, or female.

We've only just begun to understand the details of sex determination.

While temperature dependent sex determination is relatively common, there are many other environmental systems.

Today: both environmental and internal mechanisms of sex determination can operate in different species.

They later commit to sex determination, becoming either female or male under normal circumstances.

This is the common method of sex determination throughout the Hymenoptera.

He made many discoveries in the genetics and sex determination of bees.