Mass extinctions made life on Earth more diverse—and might again

https://www.popsci.com/mass-extinction-and-life-diversity/

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tk (Ton Bangkeaw/Shutterstock/)

In the past half-billion years, Earth has been hit again and again by mass extinctions, wiping out most species on the planet. And every time, life recovered and ultimately went on to increase in diversity.

Is life just incredibly resilient, or is something else going on? Could mass extinctions actually help life diversify and succeed—and if so, how? Given that we’re currently facing another extinction event, there’s extra urgency in trying to work out how mass extinctions affect diversity.

Mass extinction is probably the most striking pattern in the fossil record. Vast numbers of species—even entire families—disappear rapidly, simultaneously, around the world. Extinction on this scale usually requires some kind of global environmental catastrophe, so severe and so rapid that species can’t evolve, and instead disappear.

Catastrophic eruptions are the main driver of mass extinctions.

Catastrophic eruptions are the main driver of mass extinctions. (Wikipedia/)

Massive volcanic eruptions drove the extinctions at the end of the Devonian, Permian and Triassic periods. Global cooling and intense glaciation drove the Ordivician-Silurian extinctions. An asteroid caused the end-Cretaceous extinction of the dinosaurs. These "Big Five" extinctions get the most attention because, well, they’re the biggest. But lots of lesser yet still civilisation-threatening events occurred as well, like the pulse of extinction before the end-Permian event.

These events were indescribably destructive. The Chicxulub asteroid impact that ended the Cretaceous period shut down photosynthesis for years and caused decades of global cooling. Anything that couldn’t shelter from the cold, or find food in the darkness—which was most species—perished. Perhaps 90% of all species disappeared in just a few years.

But life bounced back and the recovery was rapid. 90% of mammal species were eliminated by the asteroid, but they recovered and then some within 300,000 years, going on to evolve into horses, whales, bats and our primate ancestors. Birds and fish experienced similarly rapid recovery and radiation. And many other organisms—snakes, tuna and swordfish, butterflies and ants, grasses, orchids and asters—evolved or diversified at the same time.

Butterflies and asters both diversified in the wake of the end-mass extinction.

Butterflies and asters both diversified in the wake of the end-mass extinction. (wikipedia/)

This pattern of recovery and diversification happened after every mass extinction. The end-Permian extinction saw mammal-like species take a hit, but reptiles flourished afterward. After the reptiles suffered during the end-Triassic event, the surviving dinosaurs took over the planet and diversified. Although a mass extinction ended the dinosaurs, they only evolved in the first place because of mass extinction.

Despite this chaos, life slowly diversified over the past 500m years. In fact, several things hint that extinction drives this increased diversity. For one, the most rapid periods of diversity increase occur immediately after mass extinctions. But perhaps more striking, recovery isn’t only driven by an increase in species numbers.

In a recovery, animals innovate – finding new ways of making a living. They exploit new habitats, new foods, new means of locomotion. For example, our fish-like forebears first crawled onto land after the end-Devonian extinction.

Evolutionary innovation

Extinction doesn’t only drive this process of speciation. It also drives evolutionary innovation. It’s not a coincidence that the biggest pulse of innovation in life’s history – the evolution of complex animals in the Cambrian Explosion – happened in the wake of the extinction of the Ediacaran animals that went before them.

Innovation may increase the number of species that can coexist because it allows species to move into new niches, instead of fighting over the old ones. Fish crawling onto land didn’t compete with fish in the seas. Bats hunting at night with sonar didn’t compete with birds that were active during the day. Innovation means evolution isn’t a zero-sum game. Species can diversify without driving others extinct. But why does extinction drive innovation?

Over 1,000 bat species have evolved without directly competing with birds.

Over 1,000 bat species have evolved without directly competing with birds. (Wikipedia/)

Stable ecosystems may prevent innovation. A modern wolf is probably a far more dangerous predator than a velociraptor, but a tiny mammal couldn’t evolve into a wolf in the Cretaceous because there were velociraptors. Any experiments in carnivory would have ended badly, with the poorly adapted mammal competing with—or just eaten by—the already well-adapted Velociraptor.

But, in the lulls after an extinction, evolution may be able to experiment with designs that are initially poorly adapted, but with long-term potential. With the show’s stars gone, the evolutionary understudies get their chance to prove themselves.

The extinction of Velociraptor gave mammals the freedom to experiment with new niches. Initially, they were poorly equipped for a predatory lifestyle, but without dinosaurs competing with or eating them, they didn’t need to be terribly good to survive. They only needed to be as good as the other things around at the time. So they flourished in an ecological vacuum, ultimately evolving into big, fast, intelligent pack hunters.

Creative destruction

Life isn’t just resilient, it thrives on adversity. Life will even recover from the current wave of human-induced extinctions. If we disappeared tomorrow, then species would evolve to replace woolly mammoths, dodo birds and the passenger pigeon, and life would likely become even more diverse than before. That’s not to justify complacency. It won’t happen in our lifetime, or even the lifetime of our species, but millions of years from now.

This idea that extinction drives innovation may even apply to human history. The extinction of ice-age megafauna must have decimated hunter-gatherer bands, but it also may have given farming a chance to develop. The Black Death produced untold human suffering, but the shakeup of political and economic systems may have led to the Renaissance.

Economists talk about creative destruction, the idea that creating a new order means destroying the old one. But evolution suggests there’s another kind of creative destruction, where the destruction of the old system creates a vacuum and actually drives the creation of something new and often better. When things are at their worst is precisely when the opportunity is the greatest.


Nick Longrich is a Senior lecturer of Palaeontology, at Milner Centre for Evolution, University of Bath.

This article was originally featured on The Conversation.

The Conversation

via Popular Science – New Technology, Science News, The Future Now https://www.popsci.com

September 17, 2019 at 08:07AM

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Genetically Modified Mosquitoes Are Breeding in Brazil, Despite Biotech Firm’s Assurances to the Contrary

https://gizmodo.com/genetically-modified-mosquitoes-are-breeding-in-brazil-1838146152

Jacobina, Brazil, where hundreds of thousands of genetically modified mosquitoes were released from 2013 to 2015.
Image: Ari Rios (CC BY-SA 3.0

An experimental trial to reduce the number of mosquitoes in a Brazilian town by releasing genetically modified mosquitoes has not gone as planned. Traces of the mutated insects have been detected in the natural population of mosquitoes, which was never supposed to happen.

The deliberate release of 450,000 transgenic mosquitoes in Jacobina, Brazil has resulted in the unintended genetic contamination of the local population of mosquitoes, according to new research published last week in Scientific Reports. Going into the experimental trial, the British biotech company running the project, Oxitec, assured the public that this wouldn’t happen. Consequently, the incident is raising concerns about the safety of this and similar experiments and our apparent inability to accurately predict the outcomes.

The point of the experiment was to curb the spread of mosquito-borne diseases, such as yellow fever, dengue, chikungunya, and Zika, in the region. To that end, Oxitec turned to OX513A—a proprietary, transgenically modified version of the Aedes aegypti mosquito. To create its mutated mosquito, Oxitec took a lab-grown strain originally sourced from Cuba and genetically mixed it with a strain from Mexico.

The key feature of these bioengineered mosquitoes is a dominant lethal gene that (supposedly) results in infertile offspring, known as the F1 generation. By releasing the OX513A mosquitoes into the wild, Oxitec hoped to reduce the population of mosquitoes in the area by 90 percent, while at the same time not affecting the genetic integrity of the target population. The OX513A strain is also equipped with a fluorescent protein gene, allowing for the easy identification of F1 offspring.

Starting in 2013, and for a period of 27 consecutive months, Oxitec released nearly half a million OX513A males into the wild in Jacobina. A Yale research team led by ecologist and evolutionary biologist Jeffrey Powell monitored the progress of this experiment to assess whether the newly introduced mosquitoes were affecting the genes of the target population. Despite Oxitec’s assurances to the contrary, Powell and his colleagues uncovered evidence showing that genetic material from OX513A did in fact trickle to the natural population.

“The claim was that genes from the release strain would not get into the general population because offspring would die,” Powell, the senior author of the new study, said in a press release. “That obviously was not what happened.”

That genetic material from OX513A has bled into the native species does not pose any known health risks to the residents of Jacobina, but it is the “unanticipated outcome that is concerning,” said Powell. “Based largely on laboratory studies, one can predict what the likely outcome of the release of transgenic mosquitoes will be, but genetic studies of the sort we did should be done during and after such releases to determine if something different from the predicted occurred.”

Indeed, lab tests conducted by Oxitec prior to the experiment suggested that around 3 to 4 percent of F1 offspring would survive into adulthood, but it was presumed these lingering mosquitoes would be too weak to reproduce, rendering them infertile. These predictions, as the new research shows, were wrong.

To conduct the study, Powell and his colleagues studied the genomes of both the local Aedes aegypti population and the OX513A strain prior to the experiment in Jacobina. Genetic sampling was performed six, 12, and 27 to 30 months after the initial release of the modified insects. The researchers uncovered “clear evidence” showing that portions of the genome from the transgenic strain had “incorporated into the target population,” the authors wrote in the new study. The project resulted in a “significant transfer” of genetic material—an amount the authors described as “not trivial.” Depending on the samples studied, the researchers found that anywhere from 10 to 60 percent of mosquitoes analyzed featured genomes tainted by OX513A.

As the researchers note in the study, the Oxitec scheme worked at first, resulting in a dramatic reduction in the size of the mosquito population. But at the 18-month mark, the population began to recover, returning to nearly pre-release levels. According to the paper, this was on account of a phenomenon known as “mating discrimination,” in which females of the native species began to avoid mating with modified males.

The new evidence also suggests that some members of the F1 generation were not weakened as predicted, with some individuals clearly strong enough to reach adulthood and reproduce. The mosquitoes in Jacobina now feature genetic traits from three distinct mosquito populations (Cuba, Mexico, and local), which is a potentially troubling development. In nature, the intermingling of traits between different species can sometimes provide an evolutionary boost in a phenomenon known as “hybrid vigor.” In this case, and as the researchers speculate in the new study, the added genetic diversity may have resulted in a more “robust” species, a claim Oxitec denies.

Powell and his team tested the hybrid mosquitoes to determine their susceptibility to infection by Zika and dengue. The researchers found “no significant differences,” as noted in the study, but “this is for just one strain of each virus under laboratory conditions,” and that “under field conditions for other viruses the effects may be different.” It’s also possible that the intermingling of genetic traits might have also introduced entirely new characteristics, such as increased resistance to insecticides, the authors warned in the new paper.

An Oxitec spokesperson told Gizmodo the company is “currently in the process of working with the Nature Research publishers to remove or substantially correct this article, which was found to contain numerous false, speculative and unsubstantiated claims and statements about Oxitec’s mosquito technology.” The spokesperson provided a three-page document detailing Oxitec’s concerns with the research, noting that the new paper did not identify any “negative, deleterious or unanticipated effect to people or the environment from the release of OX513A mosquitoes.”

According to Oxitec, the “OX513A self-limiting gene does not persist in the environment,” and that the “limited 3-5% survival of the OX513A strain means that, within a few generations, these introduced genes are completely eliminated from the environment.”

Oxitec also disputes the researchers’ claim that female mosquitoes began to avoid mating with modified males, saying, “Selective mating has never been observed in any releases of close to 1 billion Oxitec males worldwide. The authors provide no data to support this hypothesis.”

Gizmodo reached out to Powell for comment did not hear back by the time of posting.

German broadcaster Deutsche Welle reports that the news that the Oxitec experiment didn’t go as planned is raising alarms among scientists and environmentalists:

Biologists critical of genetic engineering go one step further with their criticism, among them the Brazilian biologist José Maria Gusman Ferraz: “The release of the mosquitos was carried out hastily without any points having been clarified,” Ferraz told the newspaper Folha de S. Paulo.

The Munich-based research laboratory Testbiotech, which is critical of genetic engineering, accuses Oxitec of having started the field trial without sufficient studies: “Oxitec’s trials have led to a largely uncontrollable situation,” CEO Christoph Then told the German Press Agency, dpa. “This incident must have consequences for the further employment of genetic engineering”, he demanded.

That this project didn’t go as planned is legitimately troubling. The episode demonstrates that releasing genetically modified organisms into the wild can have unintended, unpredictable consequences and that independent scientific monitoring of the outcomes is crucial.

via Gizmodo https://gizmodo.com

September 16, 2019 at 05:03PM

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Engineering: Timelapse Of A 30,000 Ton Bus Terminal Getting Rotated 90-Degrees

https://geekologie.com/2019/09/whoa-timelapse-of-a-30000-ton-bus-termin.php


This is a timelapse video from Xiamen, China of a bus terminal in the way of a new highspeed railway station being rotated 90-degrees to make room for the new construction. The outer ring of the terminal was moved a very impressive 288-meters (945 feet), and set a new Guinness World Record for longest arc rotation in the process. Talk about a feat of engineering. For reference, if I were in charge I would have just demolishing the bus station with the intention of building a new one but never built a new one because I misappropriated all the funds and I’m incredibly lazy. Related: do you think a person on their deathbed has ever regretted napping? Keep going for the video.

Thanks to Carmen, who informed me he saw the same thing attempted with a home once with much more disastrous results. Man, wish I could have been there.

via Geekologie – Gadgets, Gizmos, and Awesome https://geekologie.com/

September 16, 2019 at 01:03PM

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Google may soon let you search with a screenshot

https://www.engadget.com/2019/09/16/google-smart-screenshot-apk/

Google might be about to do pair up two mobile screen-related features, "Edit & Share screenshots" and the AI-powered "What’s on my Screen," according to some APK digging by 9 to 5 Google. A new feature called "Smart Screenshots," tucked into the latest version of the Google 10.61 app, brings up an updated toolbar when you take a screenshot. As before, you get edit, share and the option to use your favorite app to send the shot, but there’s a new option with the latest version: Lens.

By selecting Lens, you can perform a search, do optical character recognition (OCR) or find visually similar items. The current annotating, cropping and sharing editing tools will likely remain as they are. It’s not yet clear whether the new Lens function will work for all screenshots or just those taken in Google Search. However, it seems likely that it will eventually become a replacement for screen search, in much the same way that Lens has taken over from other Google Assistant functions.

Source: 9 to 5 Google

via Engadget http://www.engadget.com

September 16, 2019 at 02:21AM

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Amazon Music HD offers lossless streaming starting at $12.99 per month

https://www.engadget.com/2019/09/17/amazon-music-hd-high-quality-lossless-audio-streaming/

Amazon is launching a new tier for its Music subscription service that will offer high quality, lossless audio streams and downloads, the company has announced. With Amazon Music HD, as the plan is called, Amazon says people are going to have access to over 50 million high-resolution tracks at CD quality and better, thanks to support for 16-bit files and sample rates of 44.1kHz and above. The service will also come with "millions of tracks in UHD," which includes hi-res audio streaming at up to 24-bit/48kHz (or 96 to 192kHz) — in case you’re a hardcore audiophile and need the absolute highest quality possible.

Set to live inside the existing Amazon Music app, available for iOS, Android, the web and Amazon’s Fire and Echo devices, Music HD is rolling out starting today in the US, UK, Germany and Japan. Here in the States, the streaming service will cost $12.99 per month for Amazon Prime members, or $14.99 for regular customers. If you’re one of the "tens of millions" already paying for Music Unlimited, that means you only have to shell out $5 more per month for the new hi-res, lossless audio subscription. And, for those who haven’t paid for its music-streaming service yet, Amazon is offering new subscribers a free 90-day trial to Music HD.

FRANCE-US-INTERNET-TECHNOLOGY-MUSIC

Steve Boom, VP of Amazon Music, told Engadget that the company wanted to launch Music HD because even though streaming services give people access to millions of songs on demand, they’re not listening these tunes as it was intended. "We’re not hearing music the way the artist records it in the studio," he said. "It means you’re missing out on highs of music, lows of music, the details in the music." He added that Amazon has spent a lot of time talking to consumers and artists, who both agree they want a better, higher quality listening experience.

At the same time, Boom knows the audience for hi-res audio streaming may be niche, but he believes that doesn’t have to be the case. That’s why Amazon wanted to price Music HD competitively, he said, noting that the company will make a major push to try to sell people on its new service. At $12.99 for Prime customers, Music HD is $7 cheaper than similar premium offerings like Tidal HiFi, which is $19.99 per month. Boom also said Amazon plans to expand outside the US, UK, Germany and Japan eventually, but right now it just wanted to focus on its biggest music markets. "Wherever the consumer demand is, we will go meet it," he said.

via Engadget http://www.engadget.com

September 17, 2019 at 08:03AM

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Cows Burp Out Tons of Methane. Feeding Them Seaweed Could Help

http://blogs.discovermagazine.com/crux/?p=13134

Adding seaweed to cows’ diet would help tamp down their methane emissions. (Credit: Jan K/ Shutterstock)
Every morning, Breanna Roque goes out to the barn to feed the cows. But this isn’t your typical farm – in fact, it’s a laboratory. The University of California, Davis graduate researcher spends her time among bovines, tweaking their diets so that they burp less. Why? Less burps means less methane. And less methane, on a global scale, could mean slowing down climate change.  
Roque is p

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September 16, 2019 at 07:04PM

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NASA Puts Bigelow Aerospace’s Giant Inflatable Space Habitat Prototype to the Test (Photos)

https://www.space.com/bigelow-aerospace-space-habitat-nasa-test.html

NORTH LAS VEGAS, Nev. — NASA is kicking the tires on one of its prospective astronaut abodes.

The space agency is currently conducting a two-week ground test on Bigelow Aerospace’s B330 habitat here at the company’s headquarters. Eight NASA astronauts have participated in the trial so far, and four were on the scene Thursday (Sept. 12) to assess various aspects of the big, expandable module.

The tests, which involve two B330 test units, are part of NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) program. In 2016, NextSTEP awarded funding to Bigelow and five other companies to develop ground prototypes for habitats that could help NASA astronauts journey to the moon, Mars and other deep-space destinations.

Related: Inflatable Space Stations of Bigelow Aerospace (Infographic)

Bigelow is the last of the awardees to go through this round of ground tests, NASA officials said. But that doesn’t mean a decision is imminent.

“The purpose of this test program is not to pick a winner or a loser but to find what we like and what we don’t like,” former NASA astronaut Mike Gernhardt, the principal investigator for the NextSTEP habitat-testing program, said during a media event here Thursday. (Reporters were allowed to photograph the interior of one of the test modules, the all-steel Mars Transporter Testing Unit. But the other one was off-limits for imagery.)

“And that will all be melded into requirements going forward for the final flight design,” added Gernhardt, who flew four space shuttle missions during his astronaut career. 

Inside Bigelow Aerospace's all-steel Mars Transporter Testing Unit, during a NASA ground test of the company’s B330 habitat concept on Sept. 12, 2019.

Inside Bigelow Aerospace’s all-steel Mars Transporter Testing Unit, during a NASA ground test of the company’s B330 habitat concept on Sept. 12, 2019.

(Image credit: Mike Wall/Space.com)

The B330 is designed to be an independent space station; it will have its own life-support and propulsion systems, for example. The module takes its name from its 330 cubic meters (11,650 cubic feet) of internal volume. That’s a lot of space. For comparison, the pressurized volume of the entire International Space Station (ISS) is about 930 cubic m (32,840 cubic feet).  

The B330 is designed to support four astronauts indefinitely and five “for many months,” Bigelow Aerospace founder and President Robert Bigelow said in a statement today.

Bigelow Aerospace founder and President Robert Bigelow (left) and former NASA astronaut Mike Gernhardt, the principal investigator of NASA's Next Space Technologies for Exploration Partnerships (NextSTEP) habitat-testing program, stand outside Bigelow’s Mars Transporter Testing Unit on Sept. 12, 2019.

Bigelow Aerospace founder and President Robert Bigelow (left) and former NASA astronaut Mike Gernhardt, the principal investigator of NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) habitat-testing program, stand outside Bigelow’s Mars Transporter Testing Unit on Sept. 12, 2019.

(Image credit: Mike Wall/Space.com)

Like Bigelow’s other habitats, the B330 is expandable; see, for example, the much smaller and more bare-bones Bigelow Expandable Activity Module, which has been attached to the ISS on a test run since 2016. At launch, the B330 will be compressed enough to fit inside a 16.5-foot-wide (5 m) payload fairing. After it reaches space, the module will be inflated using onboard gas canisters.

The module’s expandable nature is its chief selling point; the B330 will provide much more habitable volume per unit of launch mass than is available in a traditional aluminum module, Bigelow Aerospace representatives stressed. 

Blair Bigelow, Bigelow Aerospace's Vice President of Corporate Strategy, gives a tour of the company's Mars Transporter Testing Unit on Sept. 12, 2019. (The "does not exist" tags point out pieces that would not be part of the real space habitat, which wouldn't need walkways and other gravity-related structural elements.)

Blair Bigelow, Bigelow Aerospace’s Vice President of Corporate Strategy, gives a tour of the company’s Mars Transporter Testing Unit on Sept. 12, 2019. (The “does not exist” tags point out pieces that will not be part of the real space habitat, which won’t need walkways and other gravity-related structural elements.)

(Image credit: Mike Wall/Space.com)

Bigelow hopes that NASA ultimately selects the B330 for use on the Lunar Gateway, the moon-orbiting space station the agency plans to begin assembling in 2022 as part of the Artemis program. (Artemis also aims to put two astronauts down near the lunar south pole by 2024 and to establish a sustainable, long-term presence on and around the moon by 2028).  

Indeed, much of the current ground test is Gateway-centric, Gernhardt said. For example, one of the many test tasks involves assessing how astronauts would operate rovers on the lunar surface from the various habitats.

Bigelow Aerospace's B330 habitat will feature two lavatories.

Bigelow Aerospace’s B330 habitat will feature two lavatories.

(Image credit: Mike Wall/Space.com)

Getting a B330 up to the Gateway is the company’s chief focus at the moment, Robert Bigelow said during Thursday’s event. If NASA does go with a B330, he added, Bigelow Aerospace could get one ready for launch within 42 months of receiving the green light.

NASA envisions the Gateway, and the lunar exploration it will help enable, as a steppingstone to the ultimate human-spaceflight destination: Mars. And the Gateway could also be the start of even bigger things for the B330, if things go according to plan for Bigelow.

“It can go anywhere,” Robert Bigelow said. “We have an architecture where we make it a lunar base.”

Mike Wall’s book about the search for alien life, “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook

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September 13, 2019 at 05:47AM

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