Long fathers were notified to wear boxing boards and to avoid hot tubes, to avoid too much heat damaging their reproductive opportunities.
Now it's turning the same effect – but there may be stronger heat waves that are driven by climate change – maybe behind huge reductions in insect numbers, he said Scientists in a study published on Tuesday in the Nature Communications magazine.
They found that the male red flour beetles that are exposed to heat temperatures in the laboratory have half the expected number of children, and that the exposure to hot heat, 10 days later, has been attracted to almost males.
Male flour beetles by heat-damaged dads also lived shorter lives and had much less success in reproduction, says Matt Gage, a biologist at the University of East Anglia in Norwich, England, and the head of the research team.
Although fewer pests in your flour may sound like good news, it seems that the same principles could be further relevant to the food chain, including potential people.
"We've been aware of hundreds of years that male fertility is heat sensitive," said Gage to the Thomson Reuters Foundation.
But, in particular, "the impact of intergenerationalities was very surprising" in the new research, he said.
"Effectively we heat up the planet and that prevents us from reproduction."
The 2017 study found that flying bird populations in German nature reserves migrated over 75 per cent for over 30 years.
The Gage team believes that it could be associated with an increasing number of heat hours over those decades – anxiety about the planet's biodiversity – which could be a parent – as climate change would bring hot, hot, hot tones.
Relevant to people?
Birth rates among people are already disappearing in very hot periods, and not because the possibility of a special scary can sound quite unpleasant, scientists believe.
A study published in this year's Demography journal found that "conceptual factor" was probably "sexually susceptible" behind dips in a heat wave concept, said Gage.
Instead, excessive heat may have damaged sperm, resulting in the risk of genetic harm and successful pregnancy being less likely, he said.
Could not one day notice notices doctors warn parents would not be pregnant during heat waves, to avoid potential genetic damage?
Gage is not as sure.
"We would like to know the mechanism of this cross generation damage," he said. "We know that radiation causes mutations in mothers. Heat may be doing similar things."
However, the findings of the new study "are very important in understanding how species respond to climate change," he noted.