The heat has a significant impact on male fertility

When climate change causes extreme weather events, our minds are thrown into hurricanes that pull palm trees out of the ground or the storms that bury cars. But one of the most dangerous types of extreme weather events is far less obvious than, say, a tornade that ripped the roof of a house. The heat waves kill more people than all the other combined weather events, and they grow and grow.

During the summer of 2003, about 70,000 Europeans died when a deadly heat wave swept through the region. As the globe continues to warm, 150 Americans are projected to die each summer in the mid - 1920 ' s. Apart from direct death from heat shock, dehydration, other hot conditions, high heat also weakens the capacity of learning. Violent crimes also tend to grow in warmer days than the average.

Now, a new study has revealed another threat coming from heat waves. It turns out that prolonged exposure to high heat reduces male fertility, and repeated exposure to successive hot waves can cause sterility.

Research of reproductive performance in heat waves conditions

The recent study published in Nature examined the endurance of red flour beetle sperm under heat waves. In a corresponding post, study author Matthew Gage wrote: A rich research since the beginning of the last century, mainly in warm - blooded mammals (including humans), has shown that environmental or experimental warming, even with a few degrees, causes a decline in sperm quality and male ability to fertilize).

He points out that most of these studies have been conducted in endocerm animals or in warm blood, but very few studies have been conducted in exotic or cold - blooded animals, such as insects. Since the vast majority of animals are ecteromic and that insects serve as food or pressure for many animals and plants, understanding how climate change affects these creatures is critical to maintaining our ecosystem. Moreover, studying insect sperm sustainability serves as a model for how heat waves will affect other animals, such as humans.

What did they find out?

Researchers exposed their beetles to heat waves over five days. Red flour beetles like temperatures of about 35 degrees Fahrenheit [35 ° C], or 95 degrees Fahrenheit [95 ° C]. The experiment exposed them to an environment that was 42 degrees Celsius, or 107.5 degrees Fahrenheit. Depending on where you live, this may sound like an impossible temperature, but the authors noted that over 90 countries experience heat waves at that temperature or higher.

After the expanded suna session, beetles were given the opportunity to join a female of their kind. Compared to male beetles in the control group, beetles that were exposed to heat were less effective. They produced 75% less sperm, and only one third of their sperm was successful. In general, the reproductive performance of the beetles exposed to heat was 50% lower.

But nature is adaptable, isn't it? One can expect beetles to finally get the initial blow of their new, hot environment and have better performance. This research showed that this was not true, at least in the short term. A second exposure to high - heat conditions made beetles almost completely sterile.

Even worse; not only were the beetles exposed to heat less effective than their colleagues in the cold, their male offspring were also less fertile than the descendants of those who were in normal temperatures. Even when this new generation of beetles was not exposed to heat conditions, they had a 25% reduction in mating success. Moreover, they lived much shorter than beetles at normal temperatures.

We've known for a time that certain environmental conditions can affect the health and fertility of offspring, but usually this is in response to radiation, exposure to toxic chemicals or stress. When an animal is exposed to an unhealthy environment, the genetic material found in their sperms becomes damaged, damaging the future generation's ability to reproduce. This study suggests that exposure to high heat damages the reproductive capacity of offspring in the same way.

Environmental impact

As this study appeared specifically in beetles, data indicates that heat waves will affect mammals in the same way. Rat exposure at warmer temperatures reduces fertility by 75%, for example. In general, this job reveals that sperm is very sensitive to heat, writes Gage. Hot environmentally hot Vals damage sperm function, leading to fertility reduction and a decline in successive performance.

If this effect is widespread, it can cause a serious monkey's grief in the internal actions of our ecosystem. The importance of insects in the diets of large animals cannot be exaggerated. As the globe continues to warm up, insect populations are falling. A study in Germany found that the local insect population had fallen 78% in just 24 years, which appears to be part of a global trend. While it cannot be said that this is entirely due to increasingly common and extreme waves, this research suggests they can play a big role.