- Duck Penis Length Depends on Other Guys
- Video: Meteor Explodes Over New Mexico
- Why Do We Care About Luxury Brands?
- Physicists Dream Up the Antilaser
- Cheaper, Better Satellites Made From Cellphones and Toys
- Under Pressure
- Genome Surprise: Guinea Pigs Have Ebola!
- Controlling Soot Might Quickly Reverse a Century of Global Warming
- Photoshop of Horrors: Wired Readers Show BP How It’s Done
- Warming of Oceans Will Reduce and Rearrange Marine Life
Posted: 02 Aug 2010 11:46 AM PDT
WILLIAMSBURG, Virginia — New measurements find that the maximum length of a duck's penis depends on the company he keeps. And in this case, it's his fellow males who make the difference.
A drake's penis substantially wastes away at the end of one breeding season and then regrows as the next season begins. Among lesser scaup and ruddy ducks, the regrowth varies in length or timing depending on whether males have to compete with a bunch of other guys, said Patricia Brennan of Yale University.
In many bird species, males don't grow specialized organs to deliver sperm. Ducks typically do, their penises sometimes reaching considerable lengths (9.8 inches for a ruddy duck, more than half its body length). That extra length may give a male a competitive advantage in delivering sperm when females have multiple mates. Brennan's past research has documented strong sexual conflict in ducks, with males forcing copulation and females employing strategies such as corkscrew-shaped vaginas, developed over the course of duck evolution, that apparently thwart male control of reproduction.
To see whether competition among males influences penis growth, Brennan housed some of her drakes in groups of seven to eight males with just five or six females. Other males lived with just one female.
Among the scaup, males competing in groups grew penises 15 percent longer, and sometimes up to 25 percent longer, than drakes with no mating rivals, Brennan reported.
The scaup species doesn't show many signs of conflict between males and females, though, she said. Scaup drakes, for example, rarely force themselves on a resistant female. In contrast, ruddy duck relations seem rife with conflict, with males often forcing themselves on females in chaotic mating scenes.
Among ruddies, penis length did not differ overall between males in competitive crowds and those in lucky privacy. What did differ was timing.
In the competitive groups, a few big males grew prodigious organs as if dominating the group. Other males grew more moderate penises, which started wasting away weeks earlier than those of dominant males or males with no competition.
Thus, Brennan said, male ducks are "prudent." In a crowd, a ho-hum male apparently doesn't bother sustaining a big investment in tissue that's not going to pay off.
The results shed light on how ducks became so well-endowed compared with other birds, Brennan said. "It's really likely that having a longer penis evolved in male-male competition." Guy-versus-guy battles then could have started playing a role in battles between the sexes.
"Elegant," says evolutionary ecologist Maydianne Andrade of the University of Toronto Scarborough, who has studied sexually cannibalistic spiders. The experiment shows that ducks "are essentially engineering their own phallus in response to social challenges." Now she'd like to know more about just how this duck physiology works and whether any other species respond to sexual competition the same way.
Image: 1) Flickr/milesizz. 2) Patricia Brennan.
Posted: 02 Aug 2010 11:31 AM PDT
A meteor exploded in the atmosphere near Santa Fe, New Mexico just before 5 a.m. on the morning of July 31. Local amateur radio astronomer Thomas Ashcraft captured the event from his personal observatory using an all-sky optical video camera developed by Sandia National Laboratories that is specifically sensitive to the near infrared flashes that meteors create.
The soundtrack comes from Ashcraft's forward-scatter radar array that is tuned to the plasma and ionization produced by meteors.
"I made the innovation of merging my radio meteor array with their optical and it produces a great deal of intricate data," Ashcraft wrote in an email to Wired.com.
The video only contains the first part of the fireball's four-minute-long echo captured by Ashcraft's antennas. Forward scatter radar is different from traditional radar detection because instead of sending out a cone of radio waves, it uses waves that are already beaming in the ionosphere.
"When a meteor strikes the Earth's atmosphere it makes a cone of ionization that has the capability of reflecting in the existing transmission beams," Ashcraft wrote. "It will reflect until the cone of ionization or plasma tube dissipates in the high atmospheric winds. Forward scatter is a 'poor man's radar' so to speak."
Ashcraft also has a network of dipole antennas on his three-acre observatory that he uses to record the sun's activity.
Posted: 02 Aug 2010 10:08 AM PDT
If I had access to a secret stash of iPhone knockoffs – a phone that worked identically to the real iPhone, but was a bootleg made of inauthentic parts – how much could I charge? Could I sell them for $10 less than the purchase price of a real iPhone? What about 25 percent off? How much is authenticity worth?
The pricing of fakes reveals something important about how the human mind calculates value. In many instances, we crave authenticity as an end unto itself. We want the real iPhone not because it works better but because it's the real one. The same logic explains why we splurge on Hermes bags, Rolex watches, Prada T-shirts, fancy Bordeaux, and expensive art. (How much would you pay for a fake Picasso print?) While a Rolex is a lovely piece of time keeping machinery, the value of the watch has nothing to do with its function. Instead, it depends on the intact authenticity of the brand.
It's easy to ridicule this behavior as mere snobbery. We might look down on the pretentious fools carrying Louis Vuitton luggage, or bragging about their Vertu phone, or wearing underwear with a big logo. We probably assume that they've just wasted a lot of money on some costly social signaling, or that they're using the brands to assuage their deep insecurity.
Unfortunately, we're all vulnerable to the same tendency. There's now suggestive evidence that our faith in the authentic – especially when the authenticity is supported by effective marketing campaigns – is a deep seated human instinct, which emerges at an extremely early age. Consider a clever experiment led by the psychologists Bruce Hood and Paul Bloom. The scientists tested 43 children between the ages of three and six. The children were shown a "copying machine" – it was actually tachistoscopes that were modified to have flashing lights and buzzers – and told that it could make an exact copy of any object. After the machine was demonstrated for the kids – the scientists "copied" a block and a rubber animal – Hood and Bloom then told the kids that the machine could also duplicate toys. A ''stretchy man'' was then placed in the box and the illusion repeated. Interestingly, the young children actually preferred the "duplicate" toy and chose it 62 percent of the time. The kids didn't worry about the "authenticity" of the stretchy man.
But Hood and Bloom didn't stop there. They also had many of the young kids bring in their "attachment objects," such as their favorite blanket or stuffed animal. (I still remember losing Johnny, my stuffed penguin, at the tender age of five. Grief.) The scientists then offered to "copy" the object for the kids. Four of the children simply refused – they wouldn't let their blankie anywhere near that nefarious device. But even those kids who allowed their attachment object to be "copied" almost always refused to see the objects as equivalent. The new duplicate was a bootleg blankie, an ersatz stuffed animal. Even though the children were assured that the objects were identical, they intuitively believed that the copy wasn't the same. It lacked a history, a bond, a sentimental attachment. It was inauthentic.
The same principle applies to brands. Although we outgrow stuffed animals, we never get beyond the irrational logic of authenticity and essentialism. There are certain things whose value depends largely on their legitimacy. While I might listen to bootleg music on my iPhone, I want the phone to be genuine. I want that Apple logo to be real. Why? Because the brand has effectively woven itself into my emotional brain.* Because when I see that logo, I don't see a functional object. Instead, I've learned to respond to everything that isn't functional, all those subtle connotations conveyed in the glossy ads. There are many blankets in the world. But there is only one blankie. The best brands are blankies.
*The clearest demonstration of this phenomenon at a neural level remains the classic McClure/Montague study of Coke and Pepsi.
Image courtesy of Rolex.com
Posted: 30 Jul 2010 12:53 PM PDT
Fifty years after physicists invented the laser, ushering in everything from supermarket scanners to music CDs, scientists have conceived its opposite — the "antilaser."
Unlike its more popular cousin, the antilaser is unlikely to take over the world. Still, it could be useful one day, for instance in new types of optical switches for computers.
"It's kind of surprising that we've been using lasers for 50 years or so, and only now somebody noticed something pretty fundamental," says Marin Soljačić, a physicist at MIT who was not involved in the work.
Instead of amplifying light into coherent pulses, as a laser does, an antilaser absorbs light beams zapped into it. It can be "tuned" to work at specific wavelengths of light, allowing researchers to turn a dial and cause the device to start and then stop absorbing light.
"By just tinkering with the phases of the beams, magically it turns 'black' in this narrow wavelength range," says team member A. Douglas Stone, a physicist at Yale University. "It's an amazing trick."
Stone and his colleagues thought up the antilaser while wondering what might happen if they replaced the material inside a laser that reflects photons — the "gain medium" — with a material that absorbs light. In the right configuration, the absorbing material sucks up most of the photons sent into it, while the remaining light waves cancel out by interfering with one another.
Stefano Longhi, a physicist at the Polytechnic Institute of Milan in Italy, calls the concept "very clever and simple."
The Yale team refers to the device as a "coherent perfect absorber." Another name is a "time-reversed laser," since it is like running a laser in reverse using an absorbing medium rather than an amplifying one, says Yale postdoctoral fellow Yidong Chong.
Even though the antilaser absorbs perfectly, it does so only at specific wavelengths of light, making it unsuitable for applications like solar panels that take in a broad range of wavelengths. (Other, specially engineered materials called metamaterials can perform those kinds of absorptions.) But because the antilaser can switch from absorbing to nonabsorbing just by changing the wavelength of the incoming light, it could prove useful in optical switches — for instance in futuristic computer boards that will use light instead of electrons.
Other Yale researchers, led by experimentalist Hui Cao, are now trying to build an antilaser. Stone says progress so far looks "very promising."
One day the antilaser could even meet up directly with its relative, the laser. In a paper submitted for publication, Longhi argues it might be possible to make a device that combines an ordinary laser with one of these new absorbers — in essence, a laser and antilaser in one.
Posted: 30 Jul 2010 12:20 PM PDT
MOUNTAIN VIEW, California — Instead of investing in their own computer research and development, engineers at the NASA Ames Research Center are looking to cellphones and off-the-shelf toys to power the future of low-cost satellite technology.
The smartphone in your pocket has about 120 times more computing power than the average satellite, which has the equivalent of a 1984-era computer inside.
"You can go to Walmart and buy toys that work better than satellites did 20 years ago," said NASA physicist Chris Boshuizen. "And your cellphone is really a $500 robot in your pocket that can't get around. A lot of the real innovation now happens in entertainment and cellphone technology, and NASA should be going forward with their stuff."
The biggest challenge of sending cellphones and toys into space is whether the parts can get up there without shaking apart and work in a vacuum at extreme high and low temperatures.
To do some preliminary testing, two Nexus One cellphones caught rides on two rockets on July 24 that launched 30,000 feet into the atmosphere at a maximum speed of mach 2.4 (about 1,800 miles per hour). One of the rockets crashed into the ground after its parachute failed, but the other made it back with the cellphone unscathed.
Both cellphones were able to record the acceleration of the rocket using their built-in accelerometers, and the undamaged phone captured 2.5 hours of video of the event through a hole in the side of the rocket.
"Everything that didn't break is a piece of data," said volunteer engineer Ben Howard. "We know that the batteries didn't break and that the computer worked the whole time."
If the cellphones ultimately get used to power satellites, they will probably be sent up without a screen and with a different battery to make them lighter. The screen and battery make up 90 percent of the Nexus One's weight.
Next, the team will build a stabilizing mechanism for the satellite using the cellphone, $100 toy gyroscopes and parts similar to those of the Mindstorms Lego, so the satellite can orient itself in space. By installing three spinning gyroscopes and getting them to spin at different velocities, a satellite can move in any direction. The same technique is currently used on many satellites, but requires multimillion dollar technology.
The project will likely use CubeSat's as a standardized carrying case for their cellphone-powered satellites, because the boxes have already been tested and are known to hold up in the journey. Often companies who are sending up satellites on rockets have extra space on their rockets, which is how most amateur satellites will likely get into space, and the people paying like to be sure that nothing will break and damage the rocket on the way up.
The whole goal of the project is to make satellites cheap and affordable, so that anyone with bit of time and a couple of thousand dollars can send their own satellite into space.
Upgrading the computing power of satellites using cellphones would mean increased satellite capabilities, possibly including artificial intelligence.
"We're not sure yet exactly what people will want to do with their satellites, and that's the point," said NASA education specialist Matt Reyes. "What can you imagine doing with your phone in space?"
Images: 1) Toy satellite parts, and the two cellphones that were retrieved from the rocket launch/ Stefan Armijo/Wired.com. 2) motorbikematt/Flickr. 3) motorbikematt/Flickr. 4) Stefan Armijo/Wired.com.
Posted: 29 Jul 2010 02:07 PM PDT
Posted: 29 Jul 2010 11:28 AM PDT
The ebola virus is one of the nastiest pathogens known to man. It corrodes blood vessels and stops clotting, leaving most of its human victims bleeding to death through their pores. And guinea pigs — along with opossums, wallabies and insect-eating bats — have it in their genes.
A genomic hunt for virus genes traced sequences to Ebola and the closely related Marburg virus in no fewer than six vertebrate species. Echoes of the less-gruesome borna virus family appeared in 13 species, including humans. The genes appear to have been mixed in about 40 million years ago, and have stuck around ever since.
"Some of these sequences have been conserved," and that's almost certainly not a coincidence, said cell biologist Ann Marie Skalka of the Fox Chase Cancer Center. "We speculate that some of these must have provided an evolutionary advantage."
Skalka specializes in RNA viruses, which unlike most common viruses are made from single strands of primitive genetic material, rather than DNA.
Common viruses, better known as retroviruses, insert their DNA into the genomes of infected cells. They hijack its function and, should the cell survive, leave pieces of themselves behind. Retroviral leftovers have accumulated for hundreds of millions of years in animal genomes; they account for about 8 percent of the human.
RNA viruses, however, were long thought to leave no leftovers. They float outside a cell's chromosomes, hijacking its machinery from afar and ostensibly leaving genomes intact. But that assumption proved wrong.
In 2007, Israeli scientists studying a bee-infecting RNA virus noticed that some colonies were unusually resistant. When they analyzed the bees' genomes, they found fragmented gene sequences resembling those from the virus. The match wasn't exact; instead, the fragments seemed to date from some ancestral infection.
The findings spurred Skalka to compare more animal genomes to other RNA virus sequences. She wasn't alone: While writing the latest paper, published July 29 in Public Library of Science Pathogens, researchers from the University of Texas published a landmark finding of ancient borna virus genes in the human genome.
While those findings stole the thunder from the latest study, Skalka's work has now expanded the evidence for genomic RNA viral fossils across the animal kingdom. "We were amazed at how many we found," she said.
Skalka's team found evidence of 80 ancient RNA viral jumps in 19 of 48 vertebrate genomes, from lampreys to cows and humans. With two exceptions — genes from the little-known Midway virus in zebrafish, and Tamana bat virus genes in a fish called the Medaka — the genes came from borna viruses or filoviruses, a family containing the dread Ebola and Marburg.
In addition to the aforementioned guinea pigs, insect-eating bats, opossums and wallabies, shrews and palm-sized primates called tarsiers contained filovirus fragments. Among the species joining humans in carrying borna virus fragments are cows, lemurs and mice.
How these gene fragments jumped from viruses to vertebrates is a matter of speculation. Skalka suspects that malfunctioning machinery in sperm or egg cells could have copied RNA virus genes, then slipped them into chromosomes later duplicated during reproduction.
Also speculative is what these viral fragments did — or still do, given their conspicuous lack of random mutations that gather in unused genes — for their unwitting recipients.
In the Israeli bees, the RNA virus genes appear to be protective; they may act like a vaccine, or jam invading viruses with almost-but-not-quite-alike proteins. That could also be the case with humans, who are generally resistant to borna virus infection, and other animals flagged by the study.
"You could imagine that the proteins made by these genes would look like the virus proteins, but they're not exactly the same. And if these funny proteins are there, maybe they muck up the works," said Skalka, who plans to focus her research on fragments in the human genome. "There would be a real advantage to that."
According to Ian Lipkin, a genetic epidemiologist at Columbia University, Skalka's "elegant study" underscores the complicated, species-spanning nature of our bodies.
"The more we delve into genomics the more we become uncertain as to who and what we are," said Lipkin. "Fragments of retroviruses represent up to 10 percent of the human genome. The number of bacteria on and in our bodies outnumber human cells by 10 to 1. These are not silent passengers."
Images: 1) An ebola virus particle./University of Waterloo. 2) A phylogenetic tree of vertebrates with approximate dates of borna (circle) and ebola (triangle) virus insertions./PLoS Pathogens.
Citation: "Unexpected Inheritance: Multiple Integrations of Ancient Bornavirus and Ebolavirus/Marburgvirus Sequences in Vertebrate Genomes." By Vladimir A. Belyi, Arnold J. Levine, Anna Marie Skalka. Public Library of Science Pathogens, Vol. 6 No. 7, July 29, 2010.
Posted: 29 Jul 2010 10:05 AM PDT
A massive simulation of soot's climate effects finds that basic pollution controls could put a brake on global warming, erasing in a decade most of the last century's temperature change.
Compared to the larger, longer term task of getting greenhouse-gas pollution under control, limiting soot wouldn't be hard. Unlike new energy technology and profound changes in lifestyle, the tools — exhaust filters, clean-burning stoves — already exist.
"Soot has such a strong climate effect, but it has a lifetime in the atmosphere of just a few weeks. Carbon dioxide has a lifetime of 30 to 50 years. If you totally stop CO2 emissions today, the Arctic will still be totally melted," said Stanford University climate scientist Mark Jacobson. If soot pollution is immediately curtailed, "the reductions start to occur pretty much right away. Within months, you'll start seeing temperature differences."
Jacobson's simulation, currently in press at the Journal of Geophysical Research-Atmospheres, is the latest in a line of studies showing a powerful climate role for fine soot, also known as black carbon. (That's a somewhat misleading appellation, since some carbon is brown, and the pollution in soot contains a host of other compounds.)
Soot comes from the incomplete combustion of fossil fuels, and also from the burning of wood or dung for fuel. Crop residue and forest-burning are another major source. When aloft, the dark particles absorb sunlight, raising local temperatures and causing rain clouds to form, which in turn deprive other areas of moisture. When soot lands on snow or ice, its effects are magnified, because melts reveal fresh patches of heat-absorbing dark ground.
In 2003, a NASA simulation blamed soot for 25 percent of the past century's observed warming. A study last year suggested that soot was responsible for almost half of a 3.4-degree Fahrenheit rise in average Arctic temperatures since 1890 — a greater rise than anywhere else on Earth.
Soot also appears to be a culprit in drastic melts of Himalayan glaciers which provide water to much of South Asia, and in disrupting the monsoon cycles on which the region's farmers rely. The United Nations puts the soot-related death toll at 1.5 million people annually.
Jacobson's simulation, the culmination of 20 years of research on the dynamics of soot and its interaction with local, regional and global climate dynamics, reinforces those findings. It also studies a question implicit in the earlier studies, but not yet modeled: What would happens if soot pollution stopped?
"If you just eliminate soot, you get a significant climate benefit, and you can do it on a short time period, because soot has a life of just a few weeks," said Jacobson. "You don't get the full response for a while, as there are deep ocean feedbacks that take a long time, but it's a lot faster than controlling CO2."
Jacobson simulated the effects of curtailing soot from fossil-fuel emissions, something that's already possible with tailpipe and smokestack filters. He simulated the effects of replacing wood- and dung-burning cookfires with clean-burning stoves. And he simulated both advances simultaneously.
If soot disappeared overnight, average global temperatures would drop within 15 years by about 1 degree Fahrenheit, maybe a little more. That's about half the net warming — total global warming, minus cooling from sun-reflecting aerosols — experienced since the beginning of the industrial age. The effect would be even larger in the Arctic, where sea ice and tundra could rapidly refreeze.
"It will take some decades to phase down fossil-fuel emissions, so reducing dirty aerosols [soot] while we are doing that may help retain Arctic sea ice," said NASA climatologist James Hansen, one of the first researchers to study soot dynamics. But he emphasized that soot control is only a stopgap measure. "We should reduce soot for several reasons, especially its health effects, but it is only a modest help in controlling global warming," he said.
Nevertheless, soot could ease the delay between controlling greenhouse gas emissions and cooling. It might also help "avoid tipping points — nonlinear, abrupt and potentially irreversible climate change, especially in the Arctic," said Erika Rosenthal, a climate policy expert at the progressive nonprofit Earthjustice.
Soot-control policy, however, is scattered. According to Jacobson, climate policymakers have paid little attention to soot. Compared to well-studied greenhouse gases, its climate role is new and unfamiliar. "There are international efforts to limit greenhouse gases, but they completely ignore soot as something to control from a climate perspective," said Jacobson.
The draft international climate treaty negotiated last year in Copenhagen doesn't contain soot-specific provisions, but the United Nations Environmental Program is meeting in February to discuss policy options on soot. A relatively little-known U.N. effort called the Convention on Long-Range Transboundary Air Pollution has also established a black-carbon working group.
In the United States, a rare bipartisan environmental bill sponsored in 2009 by climate skeptic James Inhofe (R-Oklahoma) and environmentalist Barbara Boxer (D-California) foundered after its inclusion in massive energy legislation that recently died in Congress. It would have required the EPA to study and possibly regulate black-carbon emissions.
In anticipation of these legislative difficulties, the EPA was charged this year with launching a black-carbon study. More immediately, Congress is now debating reauthorization of the Diesel Emissions Reduction Act, a federal program that pays for putting clean tailpipes on diesel-fuel–burning automobiles, a prime source of black carbon. According to Rosenthal, the program has been fantastically successful, with retrofit requests exceeding available funds by $2 billion.
Controlling crop and forest burns isn't so easy, but clean stoves could be provided to the developing world for relatively little money. "We have the technology now. It's a matter of implementing it," said Rosenthal.
"It's low-hanging fruit," said Jacobsen. "It's straightforward to address, and it can be addressed."
Images: 1) Rennett Stowe/Flickr. 2) Average global air temperature decline following elimination of fossil-fuel–based soot (dotted line) and fossil-fuel– plus biofuel–based soot (solid line).
Citation: "Short-term effects of Controlling Fossil-Fuel Soot, Biofuel Soot and Gases, and Methane on Climate, Arctic Ice, and Air Pollution Health." By Mark Jacobson. Journal of Geophysical Research-Atmospheres, in press.
Posted: 28 Jul 2010 04:57 PM PDT
<< previous image | next image >>
We asked you last week to help us show BP that when hiring unethical photographers (or photo editors) in the future, they should look for Photoshop proficiency on their resumes.
In response, you put the company's pathetic photo-doctoring of oil-cleanup press photos to shame. Your work was not only more skilled, it was far more imaginative. Why just remove the ground beneath a parked helicopter when you could put that chopper on the moon instead?
As Kanye West would probably tell BP, "Ima let you finish your top kill, but … "
We've got some of the best, most clever and funniest of your work in this gallery, but if you want to see more, including some great ones that were too small to include here, check out the submissions at the bottom of last week's call for submissions.
The titles and captions were written by the artists.
BP Encounters an Act of God…
Submitted by cybersox13
Posted: 28 Jul 2010 12:43 PM PDT
The warmth of the ocean is the critical factor that determines how much productivity and biodiversity there is in the ocean, and where.
In two separate studies, researchers found that warming oceans have led to a massive decline in the amount of plant life in the sea over the last century, and that temperature is tightly linked to global patterns of marine biodiversity.
"We are just now understanding how deeply temperature affects ocean life," said biologist Boris Worm of Dalhousie University, a co-author on both papers appearing July 28 in Nature. "It is not necessarily that increased temperature is destroying biodiversity, but we do know that a warmer ocean will look very different."
In one study that looks at historical records of algae abundance over the last hundred years, Worm and his co-authors found that warming ocean temperatures are correlated to a massive decline in the amount of marine algae, or phytoplankton. Marine algae are the base of the entire ocean food chain, and were also responsible for originally creating oxygen on the planet.
The study estimates the decline in marine algae has been approximately 40 percent since 1950.
"I think that if this study holds up, it will be one of the biggest biological changes in recent times simply because of its scale," said Worm. "The ocean is two-thirds of the earth's surface area, and because of the depth dimension it is probably 80 to 90 percent of the biosphere. Even the deep sea depends on phytoplankton production that rains down. On land, by contrast, there is only a very thin layer of production."
The study on marine phytoplankton is the first to look at changes over the last century at a global scale with data from as far back as 1899. Similar models have been made using satellite data, but that data only extends back to 1979.
"One of the most important aspects of the new paper is that they've come up with the same answer but from a different approach than we saw from space," said marine botanist Michael Behrenfeld of Oregon State University. "I think that we should be concerned that this convergence of multiple approaches sees a reduction in the phytoplankton pigments as the ocean warms. If we continue to warm the climate we will probably see further reductions."
In a study of general marine biodiversity, scientists have made the first global map of the biodiversity of the oceans for more than 11,000 marine species, from tiny shrimp-like creatures to whales, building on 6.5 million records from the Census for Marine Life and other databases. Of all the factors they looked at to explain why some regions had more or fewer types of creatures, the only factor that consistently explained the patterns for the 13 groups of marine life they studied was temperature.
"It was surprising that we found such a strong correlation to marine biodiversity and temperature," said biologist Derek Tittensor of the University of Dalhousie, lead author of the marine biodiversity map study. "You might expect a different response to temperature from cold and warm-blooded animals, for example."
Ocean temperature had different effects on the number of different creatures in coastal habitats versus open-ocean habitats. The biodiversity hotspots for coastal marine ecosystems were mostly near the equator where ocean temperatures are warmest, much like on land.
But for open ocean ecosystems, which included many deep-sea creatures, whales and big fish like tuna, the hotspots for diversity were at the mid-latitudes, where temperatures were slightly cooler.
"What we can draw from this study is that it is very likely that we will see a reorganization of biodiversity in the ocean from a warming ocean, but right now it's very hard to predict exactly what that reorganization will be," said Tittensor.
The hotspots in biodiversity are also the areas that have attracted the most human impacts, such as fishing and habitat destruction, meaning that we are harming the areas that we should be trying to conserve.
By mapping where the biodiversity of marine life is today, scientists now have a baseline for comparing species distributions in the future. Understanding these changes will help them understand how marine biodiversity is being affected by changes in the amount of marine algae, for example.
"In order to understand life in the ocean, we need to understand where it is," said Worm. "It's a basis for understanding and also managing ocean life."
"The ocean is something that we're not very good at thinking about," Worm added. "It is one of those things that is so big to see that it has been hard to see it until now."
Images: 1)Phytoplankton Bloom Near Norway/ NASA Earth Observatory Collection. 2) Biodiversity map of coastal and oceanic marine creatures, red boxes mark hotspots/ Tittensor. 3) Papua New Guinea coral reef, A.A. Rosenfeld/Marine Photobank
Citations: 1) Daniel Boyce, Marlon Lewis and Boris Worm. "Global phytoplankton decline over the past century." Nature, July 28. 2) Derek Tittensor, Camilo Mora, Walter Jetz, Heike Lotze, Daniel Ricard, Edward Vanden Berghe, and Boris Worm. "Global patterns and predictors of marine biodiversity across taxa." Nature, July 28.
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