You might first wonder if it's genetic. Maybe some change in the makeup of a particular group being studied has caused the decline (crudely, you could call this the 'dumb people have more babies' hypothesis). But that seems to be ruled out by the new research, which shows that even within single families IQ has declined. Marginal Revolution blogger economist Tyler Cowen sums up what that means: "In other words, we have started building a more stupidity-inducing environment."
In an article called Our Fragile Intellect, Crabtree argued that human intellectual fitness has been on a slow but steady decay for 3,000 years, and it is due to our relatively easy lifestyle that has freed us from a state of 'survival by thinking.'
Research suggests that sperm counts have dropped by half in the last 50 years or so and that a higher percentage are poor swimmers.
A recent study that tested both men and dogs added to concerns that chemicals in the environment are damaging the quality and quantity of sperm
Plantagenet wrote:I like the theory that the decrease in human brain size in the late Pleistocene occurred because humans domesticated dogs. Once primitive man delegated to dogs the job of tracking animals by smell, then those parts of the human brain dedicated to deciphering smells were no longer necessary and the human brain shrunk.
I fully expect the same king of thing to happen again now that we've got cell phones. The parts of our brain dedicated to navigating and answering trivia questions can be replaced by Siri on a cell phone, so those parts of the modern human brain are now superfluous and will eventually disappear in future generations.
eclipse wrote: I learned to use a chainsaw as an adult, and my wife never jogged until her 40's and now she jogs regularly. Divergent interests, a varied population, and aged adult neuroplasticity. These are things.
Ibon wrote:eclipse wrote: I learned to use a chainsaw as an adult, and my wife never jogged until her 40's and now she jogs regularly. Divergent interests, a varied population, and aged adult neuroplasticity. These are things.
These are real assets of humans and external consequences will ramp up the ingenuity and exercise that neuropasticity as those very consequences bring back the evolutionary selection pressures to winnow down the population so that those who remain are selected for that very neuroplasticity!
You see, we have been several generations of no real winnowing, no real separating the chaff from the wheat.
All of this neuropasticity however is not going to keep the current population at the levels it is nor allow for further growth.
What is sorely lacking in our neuroplasticity is the ability to exercise humility and restraint in our breeding and consumption. But no worries, natural selection is about to return is spades in the form of consequences.
Consequences are our species friend, not our enemy. To embrace rather than battle them is a sign of advanced neuroplasticity!
The first extensively drug-resistant (XDR) strains of Salmonella Typhimurium, a pathogen which is responsible for millions of bloodstream infections per year in sub-Saharan Africa, have been identified in the Democratic Republic of Congo (DRC). Drug-resistance has increased in successive groups of S. Typhimurium over time. These new strains are resistant to all but one of the commonly available drugs in the DRC, with one sample showing reduced susceptibility to this final antibiotic.
Most Salmonella infections result in symptoms associated with food poisoning. While unpleasant, symptoms are not life-threatening in the vast majority of cases. But in sub-Saharan Africa, Salmonella such as S. Typhimurium can cause infections of the blood, known as invasive non-typhoidal Salmonella (iNTS) infections.
Every year, iNTS infections are estimated to affect 3.4 million people and result in 681,316 deaths globally, of which the majority are caused by S. Typhimurium. The containment and treatment of iNTS infections in places like the DRC is complicated by limited access to healthcare, infrastructure challenges and weakened immunity, with children under five years of age particularly at risk.
It is known that iNTS infections in sub-Saharan Africa are dominated by a type of S. Typhimurium known as ST313, which is associated with antibiotic resistance. Two groups of ST313 (named lineage I and II) split off independently and subsequently spread over the African continent. Antibiotic resistance has been growing over time, with lineage II now the primary cause of iNTS infections.
... "All antibiotic resistance genes contributing to "XDR' are present on the same plasmid. This is worrying because a plasmid is a mobile genetic element that could be transferred to other bacteria. While accumulating more antibiotic resistance, we discovered that the novel Salmonella Typhimurium line is also showing further genetic and behavioral changes which suggest ongoing evolution of the bacteria towards bloodstream infections."
The evidence is unequivocal: biodiversity, important in its own right and essential for current and future generations, is being destroyed by human activities at a rate unprecedented in human history.
Governments around the world recognised this at the Earth summit in Brazil in 1992 and established the Convention on Biological Diversity to protect and conserve biodiversity. But the situation has become more and more dire. I have chaired or co-chaired three international assessments on the state of knowledge of biodiversity, and all have repeated the same message – we are destroying it at an alarming rate. Each time we have called for action, only to be largely ignored.
[biodiversity] is central to development, through food, water and energy security. It has significant economic value, which should be recognised in national accounting systems. It is a security issue in so far as loss of natural resources, especially in developing countries, can lead to conflict. It is an ethical issue because loss of biodiversity hurts the poorest people, further exacerbating an already inequitable world. And it is also a moral issue, because we should not destroy the living planet.
To date, climate crisis has received most of the attention. The limited attention on biodiversity tends to focus on saving large charismatic animals, rather than informing the public of the importance of biodiversity to human life.
dohboi wrote:Back to general mass die off/mass extinction event:
Biodiversity touches every aspect of our lives – so why has its loss been ignored?
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