No subject

[John Grehan]

 Interesting to note that Blackburn's Blue in Hawaii
>lost its gland because there are (were?) no ants on the island.
>
>Jo

Perhaps to rephrase - they lost their glands either because
 some individuals lacked the feature and these were at 
a selective advantage in terms of reproductive output,
or because there was an orthogenetic trend resulting
in loss of the gland throughout the species.

John Grehan