Progenesis
produced by negative
allometry & early offset
Timing
of metamorphosis in ascidian Tunicates is size-dependant (B on vertical axis).
If sexual maturity is achieved at an smaller size (B B', projected on vertical axis),
functional gonads will develop prior to metamorphosis (green bar
on horizontal axis).
This produces a motile, larval-like adult with functional
gonads, similar to the model for the earliest proto-chordates.
Text material © 2024 by Steven M. Carr