Stranger things: The uncanny world of animal pregnancy

Animals are strange, but only when you’re a stranger, so join us for some intriguing insights into the uncanny world of animal pregnancy at Stranger Things, a special JD Stewart lecture to celebrate National Science Week with Dr Camilla Whittington on Wednesday 16 August.

From bacteria, to plants to cockroaches and seahorses, organisms have developed diverse methods of reproduction to ensure the continuation of their kind. But the age-old question remains: what came first, the chicken or the egg?

“Our earliest vertebrate ancestors laid eggs, well before chickens came along, so tracing back far enough in evolutionary time, we can say with some conviction that the egg came first,” said Dr Whittington from the Sydney School of Veterinary Science and the School of Life and Environmental Sciences.

“Shelled eggs contain all the nutrients a growing embryo needs, and protect it from drying out before it hatches.”   

But getting laid is not all it’s cracked up to be.

“A really important biological adaptation is to incubate embryos internally.”

And that’s what our ancestors evolved to do. Perhaps around the time of the Preggo-saurus.

“Somewhere between 160 and 140 million years ago, our mammalian ancestors developed viviparity – the ability to give birth to live young, and incubate offspring internally.”

But interestingly, viviparity has evolved independently hundreds of other times in very diverse species, including lizards, sharks, seahorses and even cockroaches.  

“Even though these animals get pregnant and give birth to live young, there are major differences in the physiology, morphology and ecology of viviparity in different species, and in the way the embryos obtain their nutrients from their mother.”

Camilla will highlight some of the weird and wonderful ways embryos get their nutrients, including eating a special egg the mother produces, eating their mother from the inside out, and even engaging in a spot of sibling cannibalism.

“Even inside the uterus, it’s a competitive case of survival of the fittest.  

“There are animals that display different incubation methods in different environments. The diversity and complexity is truly astounding, and improving our understanding of how these particular strategies have evolved provides us with a basis for predictions on how animals might respond to future environmental change,” Camilla said.

Camilla’s pet projects circumnavigate the sea-section, with much of her current research in the Syngnathidae family which includes seahorses, pipefish and weedy and leafy seadragons.

And because Camilla seems to be drawn to the stranger things in life, of course the seahorse displays something very strange indeed for the animal world.

“Male pregnancy.”

Why is this so? Did the females run out of womb?

Camilla will give us a rundown of the birds and the bees of seahorse courtship, “But what is way more exciting is the pregnancy itself.

“I am using genetic techniques to investigate the genes, or instructions that control what happens during seahorse pregnancy. We want to understand more about the seahorse pouch and the ways it protects and supports the baby seahorses.”

A seahorse can have 1500 buns in the oven at once.

“We are also learning more about pregnancy and labour hormones.

“Seahorses are emerging as important model species for understanding the evolution of viviparity and reproductive complexity, and we can draw some parallels between seahorse pregnancy and human pregnancy.”

A range of fun, hands-on activities to test your gestational, embryonic, evolutionary and animalistic knowledge will be available after the talk.  

Register now for Stranger things: The uncanny world of animal pregnancy, Wednesday 16 August in the Eastern Avenue Auditorium, Camperdown.