Koch Foundation

NOVA Science Trust Logo

Elastic Electrodes Promise More Powerful, Longer-Lasting Batteries

<section class="entry-content instapaper_body clearfix" itemprop="articleBody">
<div class="add-container clearfix" id="add-block-placer">
</div>
<p>
  A breakthrough in chemical engineering may pave the way for more powerful, longer-lasting batteries.
 </p>
<p>
  For modern battery-powered devices like electric cars, lithium-ion batteries’ relatively low energy capacity limits how far they can travel. Their anodes, the parts through which electricity enters the battery, are currently made from graphite. Batteries with graphite anodes have a relatively low battery capacity, which is why electric cars have to recharge frequently. Silicon anodes have the potential to increase battery capacity by three to five times, but lithium-silicon batteries can only be used a small number of times before they decay.
 </p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://staging.pbs.org/wgbh/nova/media/images/toshiyuki-imai.width-990_zsW8YKU.jpg"/>
<figcaption>This advancement could significantly cut down on how often you need to charge your electric devices.
        
    </figcaption>
</figure>
<p>
  The research team, based at KAIST, a South Korean research university, has developed a molecular pulley system that significantly slows the decay of the battery, making it much more practical for public use. This molecular system “resolves the issue” of silicon decay and makes lithium-silicon batteries “commercially viable,” said Soojin Park, a professor of energy and chemical engineering at the Ulsan National Institute of Science of Technology who did not contribute to the research. The team’s work was published yesterday in
  <em>
   Science
  </em>
  .
 </p>
<p>
  Silicon is cheap and there’s plenty of it, so it has great potential for use in higher capacity batteries. But as the battery charges, the silicon expands dramatically, leading to significant stress on the system and causing electrode particles to fracture. As a result, these silicon anodes quickly lose their high energy capacity.
 </p>
<p>
  According to Park, the team’s novel insight was the construction of an elastic network of molecular strings and rings that allow the anode to expand without breaking. “This system can rapidly release the internal stress,” so the battery is able to maintain a large fraction of its energy capacity over a long period of time, Park wrote in
  <a href="http://science.sciencemag.org/cgi/doi/10.1126/science.aan6685">
   a commentary
  </a>
  also published
  <em>
   Science
  </em>
  .
 </p>
<p>
<video autoplay="autoplay" height="349" loop="loop" width="620">
<source src="http://www.pbs.org/wgbh/nova/next/wp-content/uploads/2017/07/choi1.mp4" type="video/mp4"/>
</video>
</p>
<div class="inline-caption">
  A network of molecular rings and strings forms an elastic web that helps hold the anode together while charging and discharging.
 </div>
<p>
  This has important implications for the commercial use of lithium-silicon batteries, allowing people to use these more practical and powerful batteries for longer periods of time, which could help to popularize the use of electric vehicles. We could see these batteries in use in cars on the road “in the near future,” Park said.
 </p>
</section>
<p>
 Photo credit:
 <a href="https://www.flickr.com/photos/matsuyuki/3580764915/">
  Toshiyuki IMAI/Flickr (CC BY-NC 2.0)
 </a>
</p>

The Moon’s Interior Might Be Wet

<section class="entry-content instapaper_body clearfix" itemprop="articleBody">
<div class="add-container clearfix" id="add-block-placer">
</div>
<p>
  Much of the moon’s interior may contain water, new research finds.
 </p>
<p>
  Scientists from Brown University found evidence of water from satellite imaging of the remains of volcanic eruptions across the surface of the natural satellite. Since this material was expelled from below the moon’s surface, this suggests that the water came from the moon’s mantle. And nearly all the volcanic, or pyroclastic, deposits studied contained evidence of water, suggesting that the water is spread out across the planet’s whole interior and is relatively plentiful.
 </p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://staging.pbs.org/wgbh/nova/media/images/145983.width-990_kCIcYZa.png"/>
<figcaption>Evidence from ancient volcanic deposits suggests that lunar magma contained substantial amounts of water, bolstering the idea that the moon's interior is water-rich.
        
    </figcaption>
</figure>
<p>
  Here’s Space.com’s Samantha Mathewson talking to Ralph Milliken, the study’s lead author:
 </p>
<blockquote>
<p>
   “Our work shows that nearly all of the large pyroclastic deposits also contain water, so this seems to be a common characteristic of magmas that come from the deep lunar interior,” Milliken said. “That is, most of the mantle of the moon may be ‘wet.’ ”
  </p>
</blockquote>
<p>
  Scientists first began to suspect that the moon contained more than trace amounts of water back in 2011, when volcanic glass beads from the Apollo 15 and 17 missions were found to contain similar amounts of water to volcanic rock on Earth, suggesting that near the source of the Apollo samples, the moon’s interior contains as much water as Earth’s.
 </p>
<p>
  But the possibility remained that these samples were anomalous, and that the rest of the moon’s interior contained very little water. The fact that Milliken’s team, which published the research yesterday in
  <em>
   Nature Geosciences
  </em>
  , was able to find water in so many places suggests that the Apollo beads are representative of the entire mantle.
 </p>
<p>
  What’s impressive about this research is that it detects the presence of water without even landing on the moon. Satellite equipment measured the wavelengths of sunlight reflected by the moon in order to determine the minerals and compounds contained on the surface.
 </p>
<p>
  This finding raises the question of the water’s origin. Scientists previously believed that the collision that formed the moon produced too much heat for water to survive. So either the collision wasn’t too hot, or something else must have brought the moon its water.
 </p>
</section>
<p>
 Photo Credit: Olga Prilipko Huber
</p>

Should Testosterone Be Regulated in Female Athletes?

<div class="related"></div>
<p>
 In 2014, Indian sprinter Dutee Chand was barred from competing in the Commonwealth Games, an international sporting tournament between former territories of the British Empire. Chand hadn’t doped—a rampant problem in the sport—or consumed any illicit substances.
</p>
<p>
 But officials deemed that Chand, who was not favored to win the competition, had a seemingly unfair advantage: her body naturally produced a lot of testosterone.
</p>
<p>
 At least, that’s according to a regulation issued by the International Association of Athletics Federation (IAAF). Suspended in 2015 by the Court of Arbitration for Sport (CAS), the regulation was aimed at females whose bodies produce unusually high levels of androgens, a group of hormones that includes testosterone. Concerned in part that this condition, called hyperandrogenism, gave female athletes an unfair competitive advantage, the IAAF ruled that if athletes were unable to prove their body was incapable of using the testosterone, women with over 10 nanomoles of testosterone per liter of blood would either have to undergo surgery or take hormone suppressants before they would be allowed to return to competition.
</p>
<figure class="richtext-image full-width">
<img alt="Seb Coe" class="richtext-image full-width" src="https://staging.pbs.org/wgbh/nova/media/images/seb-coe.width-990_IJFToj5.jpg"/>
<figcaption>IAAF president Sebastian Coe announced last summer that the governing body would appeal the CAS's suspension.
        
    </figcaption>
</figure>
<p>
 Men typically have much higher testosterone levels then women, and the IAAF believes that this is part of the reason why, on average, elite men outperform elite women by about 10% in track and field events. Take, for example, Genzebe Dibaba, an Ethiopian distance runner who holds five women’s world records between indoor and outdoor track and field. While Dibaba runs a blazing fast 4:13 mile, all twelve American high school boys at this year’s Brooks P.R. Invitational, the premiere high school meet of the summer, bettered Dibaba’s fastest career time. It would seem that we segregate men and women in track and field events with good reason—otherwise, one of the best female milers the world has seen in years would struggle to compete in national meets at the high school level.
</p>
<p>
 The IAAF argues that to uphold the integrity of women’s athletics, testosterone levels require greater scrutiny. The organization has until today to present evidence to the CAS that they hope will convince the court to reinstate the regulation.
</p>
<div class="pullquote">
<p>
 Most experts agree that the IAAF’s body of evidence is unlikely to convince the CAS to end the suspension.
</p>
</div>
<p>
 It’s expected that the IAAF will include in its package of evidence
 <a href="http://bjsm.bmj.com/content/early/2017/06/26/bjsports-2017-097792">
  a study published earlier this month
 </a>
 in the British Journal of Sports Medicine that links testosterone levels to athletic performance in a subset of women’s track and field events. While the authors conclude that their findings suggest that female athletes with high testosterone levels have a competitive advantage in these events and imply that they support the IAAF’s regulation, other scientists argue that the study is limited, lacks conclusive evidence, and that these conclusions about the research’s broader implications are unsubstantiated.
</p>
<div class="ad"></div>
<p>
 Most experts agree that the IAAF’s body of evidence is unlikely to convince the CAS to end the suspension. But the ban’s ethical complications are manifold—and that’s where opinions differ.
</p>
<p>
 Just about everyone agrees that the sport’s governing body should regulate athletes’ use of unnatural substances, like steroids. But to what degree should they control what occurs naturally in people’s bodies?
</p>
<h2>
 The History of Sex Testing
</h2>
<p>
 Sorting people into one of two of categories isn’t easy, because sex is not a neat binary of male and female, says Katrina Karkazis, an anthropologist, bioethicist, and senior researcher at Stanford University’s Center for Biomedical Ethics whose research focuses on intersex traits. Scientists used to think people could either have an X and a Y sex chromosome, and were therefore male, or two X chromosomes, and were therefore female. But as Karkazis explains in
 <a href="http://www.tandfonline.com/doi/full/10.1080/15265161.2012.680533?src=recsys">
  her 2012 paper
 </a>
 in The American Journal of Bioethics, those aren’t the only two options. Some people are born with two X chromosomes and one Y chromosome. Also, not everyone has the same sex chromosome pairing in every cell—some people have some cells with an XY pairing and other cells with an XX pairing.
</p>
<p>
 There are also at least five other markers of sex, including hormones, internal genitalia, and external genitalia, and the way that these markers—like chromosomes—express themselves is also not black and white. To further complicate things, a person might have one of these markers present as male, another present as female, and a third present as something in between—an intersex trait.
</p>
<p>
 Sports’ governing bodies struggled for decades with what to do with athletes who can’t be sorted into one of these two categories, resulting in numerous horror stories. Jaime Schultz, a professor of kinesiology at Penn State,
 <a href="https://theconversation.com/so-what-if-some-female-olympians-have-high-testosterone-62935">
  described in The Conversation
 </a>
 “nude parades” in the 1960s in which female athletes were forced to present themselves naked to gynecologists at the 1966 European Championships and the 1967 Commonwealth Games. Later, the IAAF switched their chromosome testing to a less invasive but still ethically questionable cheek swabbing.
</p>
<p>
 The IAAF and International Olympics Committee (IOC) ended systematic sex testing in the 1990s. But individual athletes have still been subject to scrutiny by the sport’s governing bodies, most recently Chand—the Indian sprinter—and South African 800-meter runner Caster Semenya. Because of her dominant performance at the 2009 World Championships and her stereotypically masculine build, Semenya, a teenager at the time, was “reportedly subjected to a two-hour examination during which doctors put her legs in stirrups and photographed her genitalia.” After the championships, “intensely intimate details about Semenya’s body became a topic for public debate and scrutiny,” Karkazis wrote in
 <a href="http://www.tandfonline.com/doi/full/10.1080/15265161.2012.680533?src=recsys">
  her 2012 paper
 </a>
 .
</p>
<p>
 After Chand appealed the 2014 ban, the CAS reinstated her and suspended the hyperandrogenism regulation. The CAS wrote in its decision that “the Hyperandrogenism Regulations are based on an implicit assumption that hyperandrogenic females enjoy a
 <i>
  significant performance advantage
 </i>
 over their non-hyperandrogenic peers, which outranks the influence of any other single genetic or biological factor.” It gave the IAAF two years to gather evidence supporting this assumption.
</p>
<h2>
</h2>
<div class="newsletter"></div>
<h2>
 The IAAF Evidence
</h2>
<p>
 Joanna Harper, a medical physicist and the only transgender person ever to be an advisor to the IOC on matters of gender and sport, says that the IAAF is likely to include
 <a href="http://bjsm.bmj.com/content/early/2017/06/26/bjsports-2017-097792">
  a study by Stéphane Bermon
 </a>
 , a physician and exercise physiologist, that’s receiving a lot of public attention.
</p>
<p>
 The study divided athletes in each track and field event at the 2011 and 2013 World Championships into three groups based on their fT levels (fT stands functional testosterone, or testosterone that the body can use). The authors then tested for a statistically significant difference between the average times of athletes in the upper third of fT levels and those in the lower third. It concluded that “female athletes with high fT levels have a significant competitive advantage over those with low fT” in five track and field events, and that this advantage should be considered by those writing legislation.
</p>
<p>
 While it’s published in the peer-reviewed and highly respected BJSM, the study has raised a few eyebrows. Schultz is skeptical of the research’s merit because of the authors’ ties to the IAAF. Bermon, the lead author, is a member of the IAAF’s Medical and Antidoping Commission, and co-author Pierre-Yves Garnier is the Director of the IAAF’s Health and Science Department. Schultz says that “the federation has been clear that it intends to return to court with proof that testosterone is linked to improved athletic performance,” so the IAAF has a vested interest in producing results that favor the regulation. “It’s very clear that the article is written with a purpose of…[defending] that particular regulation,” Karkazis echoes. “They have a dog in this fight.” Neither author was available for comment.
</p>
<p>
 Beyond the conflict of interest, Garnier’s reputation has recently taken a hit—according to
 <a href="http://www.reuters.com/article/us-sport-doping-athletics-suspensions-idUSKCN0YW0VA">
  Reuters
 </a>
 , the IAAF suspended Garnier last summer for allegedly receiving cash payments in a cover-up of Russian doping cases.
</p>
<p>
 Three statisticians who did not contribute to the research—Dorit Hammerling of the National Center for Atmospheric Research, Joe Guinness of North Carolina State University, and Richard Smith of the University of North Carolina—say that the paper does have some statistical merits. They wrote in a group email with NOVA Next that the paper successfully demonstrates a measurable difference in performance between female athletes with high testosterone and those with low testosterone in the five relevant events.
</p>
<p>
 But these findings do come with a few caveats. First, the authors ran tests on 43 events (21 women’s and 22 men’s events), so it’s possible that a few of the five statistically significant results are due to random error. Second, the authors didn’t account for the fact that almost a fifth of the female athletes competed in both World Championships, so a significant number of subjects are counted twice. The authors also only had access to one time and one fT level for each athlete, so they could only analyze a narrow sliver of each athlete’s career. Smith thought a different type of analysis would have been better given the limited amount of available data, but he said “that would require a much higher level of statistical expertise than is show in the rest of the paper.” Smith said he would have liked to see the analysis performed excluding known dopers, whose artificially boosted T levels could have skewed the results.
</p>
<div class="pullquote">
<p>
 Two runners can have different times without one having a significant competitive advantage over the other.
</p>
</div>
<p>
 While the authors are justified in arguing that they found five significant results, some of their other claims are harder to defend. Smith points out that there’s a difference between a statistically significant result and a practically significant result. Two runners can have different times without one having a significant competitive advantage over the other. And while most in the track and field community would consider the two-second difference found between low-T 800 meter runners and high-T 800 meter runners to be significant, that’s only the authors’ best guess for the time difference—it could be a difference as small as a fraction of a second, or as large as four or five seconds. As Smith says, “the broader implications are unclear.”
</p>
<p>
 This distinction is pivotal for the IAAF. Karkazis says “the CAS didn’t say you needed a statistically significant finding, but a finding of a performance difference of a particular magnitude,” a magnitude that the study did not find. The three statisticians agree that the paper doesn’t “[settle] the issues regarding athletes such as Chand or Semenya whose eligibility to participate in female events has been challenged.”
</p>
<p>
 Finally, while the authors make clear in one part of the paper that what they’ve found is merely a correlation and that they can’t conclude that the higher fT levels are causing the better performances, their implication that this evidence is in support of the regulation makes it sound like they actually have found causation. Karkazis says that these are conclusions that “support the regulation but which the science itself in the study doesn’t support.”
</p>
<h2>
 Testosterone and ‘Fair Sport’
</h2>
<p>
 Harper acknowledges the limitations of the study but argues that “you’d see even a more robust difference between the low T and the high T athletes” if the authors had more data to work with. Much of the performance difference between men and women can be prescribed to testosterone differences, she says.
</p>
<p>
 But Karkazis begs to differ. “There are plenty of studies that show a much more complicated and equivocal relationship than what policy makers would like to claim,” she says.
</p>
<p>
 Schultz agrees, saying that “so many different variables—internal and external—have to align for top performance.” But Harper argues that it’s misleading “to compare testosterone advantages to other natural advantages,” saying the advantages of testosterone far outstrip those of other biological components. She references as evidence studies conducted in Germany in the 1970s and 1980s showing that increases in exogenous testosterone were “spectacularly effective” at improving performances in elite female athletes.
</p>
<p>
 The IAAF claims that the hyperandrogenism regulation protects the integrity of female athletics and promotes “fair sport.” But Karkazis says that by focusing on testosterone, a singular biological component, the IAAF overlooks not just other biological factors, but also inevitable social and economic inequalities in athletics. Athletes in richer countries, for example, have access to better training facilities, coaches, and equipment, and can afford to dedicate more time to training. Professional athletics will always be littered with people who have incredible genetic gifts and socioeconomic benefits. The existence of professional sports itself may even depend on that un-level playing field.
</p>
<p>
 Regardless of where experts align themselves in the debate over testosterone, most seem to agree that the IAAF’s package of evidence will not be enough to convince the CAS to reinstate the hyperandrogenism regulation. Ross Tucker, an exercise physiologist and strong advocate for the regulation,
 <a href="http://sportsscientists.com/2017/07/testosterone-performance-intersex-athletes-will-iaaf-evidence-enough/">
  wrote on his blog
 </a>
 “The Science of Sport” following the publication of the new Bermon study that “the IAAF evidence does not go far enough, either in terms of the depth or the range.”
</p>
<p>
 “To reduce an athlete’s excellence to her androgen serum level or to disqualify an athlete because of her biology doesn’t strike me as appropriate,” says Schultz. Karkazis, too, argues that women shouldn’t be forced to undergo medical treatment just so they can continue to compete. “The athletes that we’re talking about are no different than any of the other women who are born and lived as women for their entire lives. And I just cannot for the life of me see a reason to treat those women differently.”
</p>
<p>
 Photo credits:
 <a href="https://www.flickr.com/photos/globalsportsforum/6966828681/in/photolist-bBCPrT-dQmgwk-bBCVNk-boHY7C-dQmgnv-bBCWyK-aHtegt-77diQp-7d4vEM-bBCRb6-bW5n7m-a7FejC-5sTZG1-9GYjxc-e3vKUF-fczEka-boHVVs-fjVj1o-bxhuVb-e3vKXF-fczEv2-ceHp2L-fczEH2-ceHppG-9qBfdC-fjVQLf-auP7pc-fjVNtN-ou6bX9-auRMpN-aEB99p-bXkZ6x-ceHpfS-bXkZ3B-fcPYzd-ceHp6A-bW5n9f-bXkZeM-9qBfdG-5XeG8q-34Qdyx-eBZDvU-boHZzm-bXkZbT-B3r2A5-dZMJ7R-8LocBS-7mBYMi-fczE4r-cHFPow">
  Global Sports Forum/Flickr (CC BY-NC 2.0)
 </a>
 ,
 <a href="https://www.flickr.com/photos/az1172/6141323034/in/photolist-78NgQv-8uTc4N-cQ3AWw-d9bmpU-amFTnU-cRCJDY-6YGtw4-LhUfcY-cSFkUN">
  André Zehetbauer/Flickr (CC BY-NC 2.0)
 </a>
</p>

<p>Scientists debate the ethics of regulating female athletes’ testosterone levels.</p>

Deadly New Strain of Anthrax Stalks Chimps in Tropical Africa

<section class="entry-content instapaper_body clearfix" itemprop="articleBody">
<div class="add-container clearfix" id="add-block-placer">
</div>
<p>
  A population of chimps in Ivory Coast’s Taï forest is at risk of being wiped out by a frightening new threat—a diverse strain of anthrax.
 </p>
<p>
  Scientists believe that the strain,
  <em>
   Bacillus cereus
  </em>
  , causes around 40% of all wild mammal deaths in the forest and will likely extinguish this group of chimps in the next 150 years.
 </p>
<p>
  Fabian Leendertz, a researcher at the Robert Koch Institute, first noticed that the chimpanzees were dying in 2001, and, to his surprise, discovered that the bacterium anthrax was killing them. He originally thought the culprit was
  <em>
   Bacillus anthracis
  </em>
  , known to kill animals in arid regions rather than rainforests. In 2010, his team was able to pinpoint the
  <em>
   B. cereus
  </em>
  , a little-understood but evidently deadly strain that thrives in the rainforest and has cropped up in several forests across Africa.
 </p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://staging.pbs.org/wgbh/nova/media/images/chimpanzee.width-990_W1DV5Ae.jpg"/>
<figcaption>A chimpanzee can die from an anthrax infection only a few hours after first showing symptoms.
        
    </figcaption>
</figure>
<p>
  Leendertz’s team found the strain in 81 of 204 animal carcasses spanning 20 different species and found over the course of 25 years in the Taï. The researchers believe that there is a very good chance that the infection eventually will kill the remaining 400 of the forest’s chimpanzees.
 </p>
<p>
  Chimpanzees have already disappeared from four African countries, according to the World Wildlife Foundation, and the wild population has shrunk and fragmented in recent decades. Habitat loss and hunting have taken their toll, as has Ebola.
 </p>
<p>
  While scientists have injected some chimps with a vaccine, it’s not easy to capture them, and the vaccine wears off over time. On top of that, scientists still understand little about how the infection spreads and how it works.
 </p>
<p>
  Here’s Ed Young reporting for
  <em>
   The Atlantic
  </em>
  :
 </p>
<blockquote>
<p>
   “‘It definitely challenges our understanding of how anthrax works,’ says Katie Hampson from the University of Glasgow, who has studied the disease in Africa before. ‘We know almost nothing about anthrax in rainforest settings.’”
  </p>
</blockquote>
<p>
  The bacterium doesn’t just infect the chimpanzees. Beyond killing other wildlife, it’s possible it’s spreading to local humans, who eat chimpanzee meat and don’t have the tools to properly diagnose an anthrax infection.
 </p>
</section>
<p>
 Photo credit:
 <a href="https://www.flickr.com/photos/smorchon/2321103614/">
  Sergio Morchon /Flickr (CC BY-NC 2.0)
 </a>
</p>

Air pollution is an issue around the world, though its effects are not evenly distributed.

Too Much Pollution for One Place

<p>Emissions from waste treatment facilities and power plants contribute to a slow-motion public health disaster in Chester, PA.</p>

New Fossils Push Back Earliest Single-Celled Skeletons 200 Million Years

<div class="related"></div>
<p>
</p>
<p>
 Imagine trying to eat food without teeth, or walk without a backbone.
</p>
<p>
 While the single-celled organisms that dominated early Earth’s oceans didn’t have much need for teeth, they did find some evolutionary advantage in making their own minerals. According to research published last week, life has been making its own hard parts for at least 810 million years, about 200 million years longer than previously thought. It’s the first occurrence of what scientists call biomineralization, and it could give us deeper insight into both the evolution of living things and Earth’s early climate.
</p>
<p>
 Previously, scientists hadn’t found evidence of organisms making their own skeletons before the rapid diversification of life around 490-550 million years ago known as the Cambrian explosion. But in the mid-2000s, Phoebe Cohen, a Williams College paleontologist and lead author of the recent study, re-examined fossil evidence that would end up setting the date back much further.
</p>
<p>
 Cohen was in the Yukon studying microfossils from a 200-foot-thick section of lime, mudstone, and slate, and she suspected that they could have been formed by biological processes. These microfossils were originally discovered in the 1980s, when they were dated to the Neoproterozoic Era, about 250 million years prior to the Cambrian explosion. But scientists at the time were unable to determine the exact age of the fossils, nor were they able to discern whether they were crafted by geology or life itself.
</p>
<div class="ad"></div>
<p>
 To unlock the minerals’ secrets, Cohen and her co-author Nicholas Tosca borrowed a method of microscopic imaging from materials scientists that uses electrons instead of light. That imaging revealed highly organized, long, and slender crystals that were oriented and spaced in such a way that they could only have been made biologically, Cohen said.
</p>
<p>
 The minerals possibly served as an armor-like casing constructed by now-extinct organisms, though Cohen and her team did not find conclusive evidence of their function, nor did they find remnants of the cells themselves, which rarely preserve for so long. Cohen said these parts could have been a defense against a predation, since some single-celled organisms today use hard parts for protection. Plus, evidence in the fossil record suggests that predatory single-celled organisms would have existed at the same time as Cohen’s fossils.
</p>
<p>
 Shuhai Xiao, a paleobiologist at Virginia Tech who did not contribute to the paper, said it’s a reasonable hypothesis. “Organisms don’t make something just because there is material available,” Xiao said. “There must also be an ecological need.”
</p>
<p>
 Cohen and Tosca’s research cleverly uses “the way a mineral is constructed” to determine its origin, said Sara Pruss, a Smith College geologist who did not contribute to this study. It’s the first study to use a detailed analysis of crystal structure to find evidence of biomineralization. The same technique could be used to find other biomineralization from the same era in other parts of the world.
</p>
<p>
 The analysis also revealed that the minerals were composed of a particular flavor of phosphorus called hydroxylapatite, which is rarely found in oceanic single-celled organisms today. Cohen and her team found evidence in the rocks suggesting that the oceans at the time contained less oxygen than today. This provided a suitable environment for elevated phosphorus concentrations, which may have helped spur its use in biomineralization.
</p>
<p>
 “Hydroxylapatite is not very stable, so the preservation of the mineral in rocks of this age is remarkable,” Xiao said.
</p>
<p>
 The team was able to constrain the age of the fossils to an unusually narrow time-frame – 810 million years ago, give or take about 6 million years. As a result, Cohen thinks she’ll be able to find more fossils because she will only have to search a much narrower slice of the fossil record than before. “I was looking through a hundred million years of time before, and now I’m looking through ten million years,” she said.
</p>
<p>
 The new study leaves a few questions unanswered, and poses a few new ones of its own. For one, biomineralization has evolved several different times. This study illustrates how one branch of life gained the ability to make skeletal parts, but there are still several others to puzzle out. And then it blasts open a period of more than 200 million years in which scientists so far have found no evidence of biomineralization, a range of time that Cohen points out is as wide as that between the present day and the dawn of the dinosaurs.
</p>
<p>
 “We’re seeing a little bit of a mystery there,” Cohen said of the gap. They will now try to pinpoint when the shift from using phosphorus to using carbon occurred and find out what, if anything, organisms were making during that time. “That’s the big open question,” Cohen said.
</p>
<div class="newsletter"></div>
<p>
 Photo credit: Phoebe A. Cohen
</p>

<p>These 810 million-year-old fossils suggest early marine life protected itself by making skeletons from phosphorus.</p>

Protecting A Little More Land Could Save A Lot More Biodiversity

<div class="related"></div>
<p>
 Save the Amazon rainforests. Save the whales. Save the giant pandas.
</p>
<p>
 The conservation movement has historically focused on protecting a specific species or its habitat, but there are a lot of species and habitats to save—far too many to make slogans for them all. As humanity’s footprint continues to expand, the list continues to grow, spurring scientists to find a more sophisticated—though less glamorous — way to protect biodiversity. According to a new study, we may only need to protect a little more land to preserve a significantly greater amount of biodiversity.
</p>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://staging.pbs.org/wgbh/nova/media/images/33980901271_fb4cb86b57_o.width-990_6IjenEG.jpg"/>
<figcaption>An African elephant and its offspring.
        
    </figcaption>
</figure>
<p>
 The paper by Laura Pollock, Wilfried Thuiller, and Walter Jetz argues that strategies for more efficiently conserving biodiversity can pinpoint areas that could be significant contributors to global diversity–more specifically, that a 5% expansion of protected land could as much as triple the amount of protected biodiversity.
</p>
<p>
 In the past, conservation often meant rounding up endangered species and building a fence around them. But biologists know it’s not that simple.
</p>
<p>
 For one, there’s more than one type of biodiversity. For a long time, scientists primarily considered only the number of species in a protected area. But now studies like this latest one also consider phylogenetic diversity, or the degree to which the tree of life is well represented, as well as functional diversity, such as the variety of diets or body sizes, present in an ecosystem.
</p>
<p>
 Scientists also have to balance preserving high densities of biodiversity at the local level and wide ranges of biodiversity at a global level. It’s a matter of choosing between whether “we want to capture every little piece of biodiversity” or try to maximize biodiversity in certain areas, said Pollock, a postdoc at University of Grenoble in France.
</p>
<p>
 Pollock and her colleagues’ paper maps out which unprotected parts of the globe, if protected, would maximize each of these three facets of biodiversity—species, phylogenetic, and functional—for both mammals and birds. While other papers have looked at each of these aspects before, none have applied as broad a scope as Pollock’s. “What’s novel is the application to a global scale,” said Marc Cadotte, an associate professor researching conservation, ecology, and evolution at University of Toronto-Scarborough who did not contribute to this paper. “It’s nice to see this all coming together to a global view of conservation.”
</p>
<p>
</p>
<div class="ad"></div>
<h2>
 Conservation by Big Data
</h2>
<p>
 Such in-depth, large-scale analyses require a finely organized library of data and a wealth of processing power. Jetz said that this paper was six to eight years in the making—four to six years of organizing genetic data into a reasonable approximation of the tree of life, followed by two years of analyzing the data, including running algorithms that search for the most efficient ways to conserve biodiversity. “It’s computationally quite tricky to run these,” he said.
</p>
<p>
 Before, simpler analyses assumed that conserving the most diverse areas would protect the most biodiversity. When deciding whether to protect an area, biologists would only consider whether this or other areas contained more biodiversity. In their analysis, Pollock and her team didn’t assume that the most diverse areas are the most important. Instead, they checked all of the possible combinations of areas to see which protect the most biodiversity as a whole. It’s not unlike IBM’s computer Deep Blue’s strategy for defeating Grandmaster Garry Kasparov in chess, in which the computer assessed almost all possible moves for each of its turns.
</p>
<p>
 The benefit of these cumbersome analyses is that they do a much better job of conserving biodiversity than traditional methods, according to the study. Pollock and her team found that their algorithms expanded protected land by just 5% but included over 1,500 more bird species than simply prioritizing diverse areas. “We were able to much more efficiently—that is, over much less space and with much less resources—conserve more of the tree of life and functional diversity,” Jetz said.
</p>
<p>
 It’s not a universal solution, though. Local and global conservation require two very different strategies. The end goal “matters a lot in terms of which areas you would protect,” Pollock said.
</p>
<p>
 Her study also found that strategies for conserving phylogenetic and species diversity were more similar than strategies for saving functional diversity. In other words, if you’re trying to protect large chunks of the tree of life, you’ll probably succeed in conserving a lot of different species. But you might omit important functions in the ecosystem, perhaps cutting out a key link in the food chain, for example.
</p>
<p>
 Improving efficiency is a priority for conservation biologists because so much biodiversity is either poorly protected or not protected at all. According to the paper, 13% of the bird tree of life and 23% of the mammal tree of life are unprotected. Even in protected areas, diversity has suffered. Pollock said that around a quarter of all species worldwide are absent from any protected area, a fact she finds “alarming.” And even diversity currently well-contained could be lost in the future. There continue to be problems worldwide with underfunded and poorly managed conservation sites, Cadotte said, as well as sites ravaged by poachers, leaving species that are theoretically protected still vulnerable to extinction.
</p>
<p>
 Pollock and her colleagues intend to replicate and refine their methods. Future iterations of the study could use more data about each species’ role in the ecosystem, Jetz said, particularly for tropical species. They could also include a more detailed mammalian tree of life, as well as more finely grained spatial maps.
</p>
<p>
</p>
<div class="newsletter"></div>
<p>
 To him, improvements will come not from improved methods but from expanded data sets, saying that progress will “require good old-fashioned observations from the field.” Scientists only began collecting phylogenetic and functional data in the last 20 years, a relatively short time ago compared with other data. Pollock said that more work also needs to be done linking their methods to specific conservation goals, such as determining which approaches are better for global priorities than local priorities or which conserve a greater swath of the tree of life over ecosystem functions.
</p>
<p>
 The authors hope their approach will be useful both for policy makers and non-governmental organizations. Pollock sees the study not so much as rewriting the rulebook for conservation as simply shifting a perspective. “We need to start taking a broader look at these other metrics at the same time because we do not want to miss really important species,” she said.
</p>
<p>
<a href="https://mol.org/species/">
  Interactive maps
 </a>
 of global biodiversity distributions could help groups trying to shape public policy, Jetz said, pointing out that policy makers take notice when their country sticks out on conservation maps as a global priority.
</p>
<p>
 While the plans ultimately will be carried out by local governments and organizations, the global approach shouldn’t be forgotten, Pollock said. “Conservation is very narrowly focused…we very rarely look at a broader scale,” she said. “Taking a step back and keeping that larger perspective in mind when doing local conservation would be an ideal way forward.”
</p>
<p>
 Photo credits:
 <a href="https://www.flickr.com/photos/paulrin/33980901271/">
  fcmarriot/Flickr (CC BY-NC 2.0)
 </a>
 ,
 <a href="https://www.flickr.com/photos/craigoneal/3965742769/">
  Craig ONeal/Flickr (CC BY-NC 2.0)
 </a>
</p>

<p>By applying algorithms to giant datasets traits, researchers found more efficient strategies for conserving biodiversity.</p>

Will Sullivan

Articles