We all know that sharks rays and chimaeras are some of coolest things ever to swim the oceans. My research explores the big picture of the evolution and ecology of chondrichthyans. They have some of the most diverse way of producing offspring – raging from egg-laying to placental live birth and provisioning developing offspring through cannibalism, uterine milk and placentas. I want to know the sequence of evolution of this diverse array of reproductive modes and the life history and ecological correlates of the evolution of live bearing and maternal investment.
The evolution of live bearing and maternal investment
The diversity of egg-cases
The traditional view of the evolution of reproductive modes is of a progression toward increasing complexity.
We found instead that there have been numerous reversal from more complex to simpler ancestral forms – which suggests a more flexible “horses for courses’ adaptive model for the acquisition and maintenance of complex reproductive traits.
The macroecology of reproductive investment
Do live-bearing species have larger geographic ranges? Do broadcast spawners have larger geographic ranges? Scientists are keen to understand links between reproductive life histories, dispersal and the maintenance of geographic range sizes.
Life histories, demography and population dynamics
Ultimately these are just the early questions, generally I am keen on understanding life history evolution and the links to demography and population dynamics and in turn how these traits confer resilience and vulnerability to fishing