(Roughly) Daily

Henry Gee, paleontologist and senior editor of Nature, argues that we Homo sapiens are setting ourselves up for collapse. He cites population decline, a lack of genetic variation, our socioeconomic fixation on growth (and the way that that’s plundered the planet), among other factors. But he singles out one phenomenon in particular…

 The most insidious threat to humankind is something called “extinction debt.” There comes a time in the progress of any species, even ones that seem to be thriving, when extinction will be inevitable, no matter what they might do to avert it. The cause of extinction is usually a delayed reaction to habitat loss. The species most at risk are those that dominate particular habitat patches at the expense of others, who tend to migrate elsewhere, and are therefore spread more thinly. Humans occupy more or less the whole planet, and with our sequestration of a large wedge of the productivity of this planetwide habitat patch, we are dominant within it. H. sapiens might therefore already be a dead species walking.

The signs are already there for those willing to see them. When the habitat becomes degraded such that there are fewer resources to go around; when fertility starts to decline; when the birth rate sinks below the death rate; and when genetic resources are limited—the only way is down. The question is “How fast?”…

Eminently worth reading in full: “Humans Are Doomed to Go Extinct,” from @EndOfThePier in Scientific American (@sciam).

For chorus effect, see also “Headed for a sixth mass extinction? MIT geophysicist warns oceans are on the brink.”

And for a look at the (possible) aftermath, explore “The Earth After Humans.”

* Neil deGrasse Tyson

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As we remind ourselves that “hope is a discipline,” we might send expansively-creative birthday greetings to Freeman Dyson; he was born on this date in 1923. A theoretical and mathematical physicist, mathematician, and statistician, he made material contributions– both processes and concepts— in quantum field theory, astrophysics, the mathematical formulation of quantum mechanics, condensed matter physics, nuclear physics, and engineering.

He will forever be remembered by SciFi fans as the originator of the idea of (what’s called) the Dyson Sphere (or Dyson Shell): he proposed that a highly advanced technological civilization would ultimately completely surround its host star with a huge shell to capture 100% of the useful radiant energy. This Dyson Sphere would have a gigantic cluster of artificial planetoids (“Dyson cloud”) with billions of billions of inhabitants who would make use of the energy captured by the Dyson Sphere. He also made the intriguing speculation that a Dyson Sphere viewed from other galaxies would have a highly distinctive, unnatural light. He suggested astronomers search for such tell-tale colored stars, which should signify advanced, intelligent life.

Dyson was skeptical of some climate science, believing that the advantages of global warming (e.g., greater crop yields) were underweighted and that climate models were underdeveloped (and thus untrustworthy). Still he sounded the alarm (in a way resonant with Gee’s, above) as to the possibility of humanity poisoning its own future:

In the near future, we will be in possession of genetic engineering technology which allows us to move genes precisely and massively from one species to another. Careless or commercially driven use of this technology could make the concept of species meaningless, mixing up populations and mating systems so that much of the individuality of species would be lost. Cultural evolution gave us the power to do this. To preserve our wildlife as nature evolved it, the machinery of biological evolution must be protected from the homogenizing effects of cultural evolution.

Unfortunately, the first of our two tasks, the nurture of a brotherhood of man, has been made possible only by the dominant role of cultural evolution in recent centuries. The cultural evolution that damages and endangers natural diversity is the same force that drives human brotherhood through the mutual understanding of diverse societies. Wells’s vision of human history as an accumulation of cultures, Dawkins’s vision of memes bringing us together by sharing our arts and sciences, Pääbo’s vision of our cousins in the cave sharing our language and our genes, show us how cultural evolution has made us what we are. Cultural evolution will be the main force driving our future…

“Biological and Cultural Evolution– Six Characters in Search of an Author”

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