from the world's big
Humans Aren't Worst Polluters in History, Not Even Close
The foul distinction belongs to ancient cousins of ours: cyanobacteria.
This post originally appeared in RealClearScience's Newton blog. Read the original here.
If you think humans are polluting the planet to a degree never before seen in history, well, "You're suffering from a species-level delusion of grandeur," insists science writer Annalee Newitz in her new book, Scatter, Adapt, and Remember. "We're not even the first creatures to pollute the Earth so much that other creatures go extinct." That foul distinction belongs to ancient cousins of ours: cyanobacteria.
About 2.5 billion years ago, the Earth was much different than it is today. Rotating at faster speeds, there were about 450 20-hour days in a year. Far from cool and invigorating, the planet's atmosphere was superheated, and comprised mostly of methane and carbon, not oxygen and nitrogen, the primary constituents of today's atmosphere. The surface was no more hospitable to modern life. Magma seeped and bubbled amidst immense, acidic oceans. 2.5 billion years ago, Earth was a hot mess.
But in this environment -- one we would deem noxious -- life persisted. Oxygen-despising anaerobic bacteria floated in the ocean deep, kept cozy by hot magma streams. They subsisted on simple amino acids and sugars. Earth was turbulent, but alive.
Then cyanobacteria ruined everything. As the first organisms to use photosynthesis, they drank in the oceans' water and absorbed photons from sunlight, using the energy from those photons to separate water's two hydrogen molecules from its lone oxygen molecule. Afterwards, the microbes consumed the hydrogen and spit out the oxygen as a waste product.
This recipe was so successful that after millions of years cyanobacteria, also known as blue-green algae, nearly blanketed the planet's surface, continuously belching boatloads of oxygen in the process. All of the smokestacks from all of today's factories and power plants couldn't come close to their polluting prowess.
Eventually, Earth's natural oxygen absorbers -- like iron -- became saturated with the gaseous element, and an "oxygen apocalypse" ensued. We recognize oxygen as a bringer of life, but it's also a powerful degrader of organic compounds and quite toxic to anaerobes. With oxygen now suffusing throughout the atmosphere, pretty much all life except the cyanobacteria gradually became extinct. Excess oxygen also reacted with the atmosphere's methane, turning it into a weaker greenhouse gas: carbon dioxide. With a diminished ability to retain heat, the planet entered an ice age that lasted upwards of 300 million years!
One thing that this fascinating, true story demonstrates is that one bacteria's trash is another life form's treasure. Over many millions of years, organisms evolved that could use the built-up oxygen, mixing it with sugars to create energy. Pollution problem solved.
Of course, there's also a more humorous and ironic takeaway. Today, we oxygen-breathers are steadily working towards the goal of turning our Earth back into the hot mess that it once was. In 2012, humans emitted 31.6 billion tons of carbon dioxide. We're also putting more methane into the atmosphere, although at a much slower rate.
Will we ever atone for the dirty sins of our blue-green cousins and give the Earth totally back to the anaerobes? Probably not. It will take a far more concerted pollution effort than the comparatively paltry one we are currently mustering.
Primary Source: Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction, Annalee Newitz
(Image: Iron Ore Pit via Shutterstock)
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- A new study found that women clear coronavirus from their systems much faster than men.
- The researchers hypothesize that high concentrations of ACE2-expressing cells in the testes may store more coronavirus.
- There are many confounding factors to this mystery—some genetic, others social and behavioral.
Where is coronavirus hiding?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1NTgxNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0ODY4NzkxMX0.D84W6ZUOhv6Q-Ki7ddiF3zmDLK_Z6vuXtzfB9R8zLAA/img.jpg?width=1245&coordinates=0%2C179%2C0%2C180&height=700" id="1cc38" class="rm-shortcode" data-rm-shortcode-id="b4e083fb45357e1fb56a8571e8cdc553" data-rm-shortcode-name="rebelmouse-image" />
A laboratory technician at Queen Elizabeth University Hospital, Glasgow, holds a container of test-tube samples from people tested for novel coronavirus.
Further research required<div class="rm-shortcode" data-media_id="z9vH49bb" data-player_id="FvQKszTI" data-rm-shortcode-id="7ef1ab8ca2f90b28543d580c408ed25f"> <div id="botr_z9vH49bb_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/z9vH49bb-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/z9vH49bb-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/z9vH49bb-FvQKszTI.js"></script> </div> <p>The Montefiore-Einstein study is currently preliminary, and further research will be required before researchers can determine what, if anything, its results illuminate.</p><p>The study is currently published on <em>Medrxiv</em>, a <a href="https://www.aje.com/arc/benefits-of-preprints-for-researchers/" target="_blank">preprint</a> distributor. This means the study has been shared publicly before undergoing the <a href="https://undsci.berkeley.edu/article/howscienceworks_16" target="_blank">peer-review process</a>.</p><p>Preprints allow researchers to communicate their findings before official publication, which can take months if not a year or longer. This pre-publication can lead to early feedback, increased visibility, and new collaborations. It's especially helpful for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6400415/" target="_blank">early-career researchers</a> trying to establish themselves.</p><p>However, given the speed at which coronavirus is spreading, researchers have leaned on preprints as a means of disseminating data to other experts faster than the peer review allows. As a result, <em>Medrixiv</em> has seen a <a href="https://www.nytimes.com/2020/04/14/science/coronavirus-disinformation.html" target="_blank">surge of preprint studies</a>, but they must be read within the context of their preliminary status.</p><p>The Montefiore-Einstein also has its limitations. The study had an initial sample size of only 68 subjects (48 males, 20 females) and a further examination of three families. And the connection of coronavirus to ACE2 enzymes in the testes came from database research, not direct observation.</p><p>The researchers acknowledge the need for further investigation. In particular, Shastri stresses the need to confirm the coronavirus's ability to infect and multiply in testicular tissue. If other researchers find their data promising, they could move forward with new research to build upon the study and see if this clue fits into the mystery.</p>
One clue among many<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1NTc5NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTQ3NjEzMX0.G-p4KniVRhsHXoIOyFfzEARdN5nGXWWkkQa85x6_ooM/img.jpg?width=1245&coordinates=0%2C281%2C0%2C298&height=700" id="d50c6" class="rm-shortcode" data-rm-shortcode-id="938d51b21df264aae5e883e5f1f9c894" data-rm-shortcode-name="rebelmouse-image" />
Coronavirus protesters in Los Angeles. Men are more likely than women to disregard health warnings from officials.
The word "learning" opens up space for more people, places, and ideas.
- The terms 'education' and 'learning' are often used interchangeably, but there is a cultural connotation to the former that can be limiting. Education naturally links to schooling, which is only one form of learning.
- Gregg Behr, founder and co-chair of Remake Learning, believes that this small word shift opens up the possibilities in terms of how and where learning can happen. It also becomes a more inclusive practice, welcoming in a larger, more diverse group of thinkers.
- Post-COVID, the way we think about what learning looks like will inevitably change, so it's crucial to adjust and begin building the necessary support systems today.
The coronavirus pandemic has brought out the perception of selfishness among many.
- Selfish behavior has been analyzed by philosophers and psychologists for centuries.
- New research shows people may be wired for altruistic behavior and get more benefits from it.
- Crisis times tend to increase self-centered acts.