The Current

Heat waves are damaging beetle sperm, and that could be bad news for the entire planet

A new study found male beetles exposed to heat waves suffered issues with fertility and produced fewer offspring, but also passed sperm-count and life-expectancy issues on to those they did have. Could that news include a climate change warning to humans?

Questions raised over effect of extreme temperatures on biosphere, human fertility

Not only did male flour beetles father less offspring after being exposed to heat waves, but male flour beetles sired by heat-damaged fathers also lived shorter lives themselves. (Peggy Greb/Agricultural Research Service/Wikimedia Commons)

Read Story Transcript

Could the fate of the world hang on the potency of beetle sperm?

A new study suggests fertility in male beetles can be negatively impacted by heat waves, and its author argues that has implications for other species and the wider biosphere.

"Beetles do all sorts of different things … they turn over nutrients, they're important to things like soil fertility," said Matt Gage, professor of evolutionary ecology and leader of the University of East Anglia research group that published the study.

"Eighty per cent of flowering plants around the world are pollinated by insects, and beetles play a big role in that as well," he told The Current's Anna Maria Tremonti.

Beetles comprise at least a quarter of the Earth's insect population, he added.

"They're kind of core to biodiversity, and biodiversity of course is core to Earth's life support system."

There are potentially some impacts of these kind of phenomena on human fertility.- Matt Gage

The study found that male beetles had half the expected offspring when exposed to heat waves of 5 C above normal temperature for five days. Subsequent heat waves rendered the beetles sterile.

The researchers also found that the offspring they did have lived shorter lives and had similar issues with sperm competitiveness.

The study's findings raise questions about the effect on the fertility of other species, including humans. (Charlie Riedel/Associated Press)

The findings raise questions about the impact climate change could have on the planet's biosphere, and whether extreme temperatures could affect the fertility of other species, like humans.

"Humans, obviously they're warm blooded, so they can protect their body temperature to a degree from environmental variation, and we've also got things like air conditioning to escape to," said Gage. 

"But there are potentially some impacts of these kind of phenomena on human fertility."

Allan Pacey, professor of andrology at the University of Sheffield, argued "humans are very different in their physiology and lifestyle" but that research in this area is still worth investigating.

"I think it would be incredibly complex to disentangle," he said, noting there are many factors which affect fertility, such as genetics, age and lifestyle.

"But if climate change is going the way that people say it is, then we don't have a lot of time to think about this and it would be useful to know the answer before it is too late."

Click 'listen' near the top of this page to hear the full conversation.

Written and produced by The Current's Danielle Carr.


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.