The blinking red lights of climate science is sending us yet another severe warning. We are killing ourselves, and most people don’t seem to understand that fact, or they don’t care.
I refer to the fact that we are tampering with the complicated web of life by pumping deadly gases into the atmosphere. New research from stunned researchers is beginning to document disturbances within the circle of life that are unfolding at a rapid rate.
Much of the news that covers climate focus on the chaos that we witness such as wildfires in California, stronger rain-laden hurricanes, deglaciation, and other strange phenomena that are to our burning of fossil fuels which results in greenhouse gas emissions into the atmosphere. A good portion of the media fails us by not connecting the dots to the climate crisis, because deforestation, species loss, pollution, plastics, and climate change could trigger widespread adverse consequences. Rating killer, both sides bull crap - the lack of urgency is revolting and absurd. Whether the media reports it or not, this insane experiment of changing our climate will enable the collapse of “critical biological systems whose interactions and dynamics we only imperfectly understand.”
If we want to understand how we can soften the inevitable body blow we will suffer from climate change to our civilization, truth, and reality should be up there on a par with an imaginary border wall of an illegitimate president that has saturated news coverage for three years now.
One of the myriads of the threat to life on earth is the damage reproduction is experiencing from heatwaves, specifically the sex of offspring, such as sea turtles being born exclusively female in locations such as Florida and Australia. That is until the increasing heat boils the contents of the eggs and they exit the world.
This will not end well.
The Washington Post reports on the damage to male sperm that more frequent heatwaves are causing to reproduction for insects, plants, and mammals which include humans. (Note: Trump’s fossil fuel saboteurs embedded in government agencies have purged government websites of heatwave reports and data).
Isaac Stanley-Becker writes:
Heat doesn’t just kill. It is also diminishes the vitality of sperm, curtailing the capacity to reproduce, as scientists have documented.
“Heatwaves reduce male fertility and sperm competitiveness, and successive heatwaves almost sterilise males,” wrote the authors of a study published Tuesday in the peer-reviewed Nature Communications.
But the research points newly to an even longer-lasting effect. Ecologists and evolutionary biologists at the University of East Anglia in Norwich, England, found that heat stress appears to be associated with transgenerational fertility problems.
That means that organisms may bear the effects of elevated temperatures long after the initial exposure — in the form of reduced lifespans, reproductive challenges and other types of defects passed to offspring.
The scientists found that heat waves undermine sperm production and viability, and also interfere with movement through the female. They further discovered that extreme heat “reduced reproductive potential and lifespan of offspring when fathered by males, or sperm, that had experienced heatwaves.”
Matthew Gage writes in Ecology and Evolution.
Reproductive biologists have long known that male fertility and sperm function can be extra-sensitive to temperature. Evolution wouldn’t allow important organs producing such vital cells in so many species to hang so vulnerably if there wasn’t a significant benefit to their externalization. In fact, a wealth of research since the start of last Century, mainly on warm-blooded mammals (including humans), has shown that environmental or experimental warming by even a few degrees can cause declines in sperm quality and male ability to fertilise. We don’t really know why sperm cells are so vulnerable to temperature, but their highly specialized function probably has a lot to do with it: not many eukaryotic cells have to individually navigate through a non-self (and sometimes hazardous) environment and transport a perfectly-packaged code for new life to the ovum –often in competition with rival sperm.
Despite the wealth of work on fertility in warm-blooded species, which can buffer their body temperatures against environmental variation, scant attention has been paid to the impacts of thermal variation on reproduction in ‘cold-blooded’ ectotherms. Drosophila fruit flies are the exception: fly-flippers are well aware that the upper temperature when populations become non-viable is also the point at which males also become sterile. This lack of knowledge for ectothermic taxa seems an important gap: most of life on Earth is cold blooded – and most terrestrial species are insects.
Given this knowledge on heat and male fertility but neglect for ectotherms, it also seems relevant to explore how temperature affects reproduction in cold-blooded species because Earth’s climate is changing at an unnaturally fast rate, and heatwave events are predicted to be more frequent and extreme. We know that biodiversity is responding to climate change, with thousands of studies confirming this in one way or another, and we know that insect numbers are crashing, but we understand remarkably little about the particular mechanisms driving population declines. This isn’t too surprising, because the natural environment, especially when it’s changing unnaturally, is a very complex place. We therefore decided to examine in detail how heatwaves affected reproduction through an experimental approach under controlled conditions in the laboratory, and using a model insect system to inform us about what might be going on in nature. Insects are critical players in almost every terrestrial ecosystem, and ‘To a rough approximation, and setting aside vertebrate chauvinism, it can be said that essentially all organisms are insects.’ (Robert May (1988) Science).
The red flour beetle Tribolium castaneum is a truly tractable lab model, which has taught us a lot about reproduction. The beauty of the Tribolium system is that it is very amenable to very well replicated and tightly controlled experiments, and many protocols are established for measuring the dynamics of mating behaviour, reproductive fitness, paternity, egg count and hatch, sperm count and viability, and sperm migration in vivo through the female tract.Pollinators in nature are what feed us. If pollinators die, we die, it’s as simple as that.
Thanks for reading and caring.