DIVE DRY WITH DR. BILL #791: SEX CHANGE... NO THANKS

[MaxBottomtime]

You have to wade through facts and opinions. Many people these days can't tell the difference. That would explain most of these protests you see on the news every day. So many people get upset over something they perceive as fact without any effort to research the truth.

 

[drrich2]

I'm not talking about sequential hermaphrodites like the California sheephead that begin as girls but turn into men later in life.

Any thoughts on what the adaptive value is in transitional sex roles vs. 'fixed,' the latter being what seems to be the dominant approach? I recall that parrot fish also change sex over their live times; does this offer an advantage?

Richard.

 

[drbill]

Sam... we're already seeing changes in the marine biota here (and elsewhere on the California coast). Check out my article on them in California Diving News's October issue.

 

[drbill]

Any thoughts on what the adaptive value is in transitional sex roles vs. 'fixed,' the latter being what seems to be the dominant approach? I recall that parrot fish also change sex over their live times; does this offer an advantage?

Richard.

Really depends on the nature of the transitions. For example, California sheephead begin life as females and some transition later into males. Since the males mate with several females, the sex ratio in the population need not be 1:1. If a male is removed from a reef, it can be replaced and be reproductively successful. However with the turtles, gender is fixed at birth. If the population skews highly toward females in some locations, this may greatly affect reproductive success of the population in that location.