It has been estimate that, at the current rate, male fertility caused by
Y-chromosome decay will decline to 1% of its present level within 5,000
generations - roughly 125,000 years. Not exactly the day after tomorrow -
but equally, not an unimaginably long time ahead. Unless something
changes in the way we breed, women will vanish too and Homo sapiens will
disappear in the next 1-200,000 years. But is extinction inevitable?
Man seems to be addicted to finding new ways of hurting & killing each other. Chemicals in our food & water interfere with our reproductive health. I sincerely believe our extinction is closer than 125,000 years from now.
I agree...I'm not optimistic about our survival down the road...the world is too populated for sustainable healthy food, our consumer culture chews up natural resources to make products we don't need, polluting the environment in the process...if there isn't a monumental change in how we treat this Earth we are doomed as a species and we will have gotten what we deserve...this planet was better off before Man made his appearance...
I'm no scientist, but think someone meant to say infertility. I think there's so many chemicals that infiltrate our cells & increase infertility. Don't even get me started about cancers & STD's. Dennis is so right that treating our food supply & home like a sewer means we will reap what we have sown. I imagine you could Google y chromosome decay....
A documentary film entitled “The Disappearing Male” was first shown on CBC in June, 2009. It can be viewed online here.
Some of its rhetoric is reminiscent of Chicken Little:
“Where have all the boys gone?”
“Millions of males are disappearing.”
“We’re on the Titanic and we see the iceberg but we just can’t turn the ship.”
“It may be a threat to the survival of the species.”
The claims behind the rhetoric are that male to female sex ratios at birth are decreasing, sperm quality and fertility are decreasing, and genitourinary birth defects like hypospadias are becoming more common. The film blames environmental chemicals, especially endocrine disruptors, and it claims they are causing “the most rapid period of evolution our species has ever seen” and that this may lead to our extinction.
So yes, there has been a small decrease in the ratio of male to female births, and it is worth asking why; but we don’t have an answer to the question yet. Some would invoke the precautionary principle: if there is any chance that chemicals are dangerous, we should avoid exposure. The precautionary principle sounds good in theory, but there are many pitfalls in putting it into practice. Unfortunately, when we don’t fully understand the situation, our remedies may be counterproductive. For instance, the World Food Program supplied maize to Africa to stave off starvation. Maize lacks vitamin B3, and now Africa is seeing a resurgence of the vitamin deficiency disease pellagra. If you take Bisphenol A out of products, you have to replace it with something. Avoiding BPA might inadvertently increase our exposure to another hazard or cause harm to the environment. There can be unexpected and unforeseeable consequences to a proposed corrective action. It behooves us to use good science to try to understand what the decreased sex ratios mean before we go off half-cocked assigning blame and applying remedies. In Steven Novella’s excellent article on BPA he concludes:
Given the existing evidence I suspect that there are real but small effects from BPA at current human exposure. These effects may be too small to worry about, but (and here is where most agree) more research is necessary.
This film is irresponsible. It takes a legitimate scientific question and turns it into a 3-ring circus. Instead of informing the public, it distorts the facts to frighten the public. It creates fear of the plastic ducky in the kids’ bathtub. It creates guilt in parents who think they should have been able to protect their children from things like undescended testicles, which as far as we know are not preventable. It encourages paranoia.
Most people get their scientific information from the media. This film is a good example of how unreliable the media can be. Endocrine disruptors and other chemicals may be harming us: we need to continue to investigate that possibility with good science. But we don’t need to panic. Our males are not disappearing.
Thanks! It's true that none of us will have front row seats for the demise of our species. Can't find a lot to be hopeful for when much of our Middle Eastern foreign policy seems fixated on making "biblical prophecy" come to fruition. Or environmental catastrophes that further contaminate our only known habitat. Makes me sad & frustrated.
'A new look at the human Y chromosome has overturned longstanding ideas about its evolutionary history. Far from being in a state of decay, the Y chromosome is the fastest-changing part of the human genome and is constantly renewing itself.'
'In the Y, which originally had the same set of genes as the X, most of the X-related genes have disappeared over the last 200 million years. Until now, many biologists have assumed either that the Y chromosome was headed for eventual extinction, or that its evolutionary downslide was largely over and it has sunk into stagnation.
Dr. Page’s new finding is surprising because it shows that the Y chromosome has achieved an unexpected salvation. The hallmark of the Y chromosome now turns out to be renewal and reinvigoration, once the unnecessary burden of X-related genes has been shed.
“Natural selection is shaping the Y and keeping it vital to a degree that is really at odds with the idea of the last 50 years of a rotting Y chromosome,” Dr. Page said. “It is now clear that the Y chromosome is by far the most rapidly evolving part of the human and chimp genomes.”'
Well, all of these factors in mind, hopefully human ingenuity will find a way to bypass this problem somehow and not let it take its natural course, if everyone will come to their senses and stick together. As the world stands now, it follows that a 'house divided cannot stand', and that will sooner be our demise unless we can cheer the fuck up.