June 18, 2013
Appalachia may be known for many things: its music, its industry, its culture, but what about its salamanders? It turns out, of the 550 known salamander species in the world, 77 can be found in this mountainous area, more than any other one region in the world. Many of them can only be found there. But this global hotspot of salamander diversity is in danger, according to the National Zoo; global warming, which dries salamanders’ naturally wet habitats, and water pollution are the two biggest threats. All of which is why the Zoo is bringing 10 different species to an upcoming exhibit, “Jewels of Appalachia,” even as observation in the field continues.
Salamanders are known to be a hardy bunch, having survived for more than 200 million years through three mass extinctions. But, because they have relatively long lifespans, it’s unclear if the rapid pace of climate change will leave them time to adapt.
June 14, 2013
Today, the National Museum of Natural History opens a new multimedia exhibition that’s all about the stuff that makes you you.
“Genome: Unlocking Life’s Code” examines the instruction manual built into all living things: the genome, an organism’s hereditary material bundled up in the nuclei of every one of its cells.
The exhibition, which was created in collaboration with National Human Genome Research Institute, part of the National Institutes of Health, covers 4,400 square feet with interactive games, 3D models, DNA sequencing equipment and videos of real-life stories. It aims to show the relevance of modern genomic research to everyday life as genetic sequencing becomes increasingly accessible.
Marking the 10th anniversary of the completion of the Human Genome Project as well as the 60th anniversary of Watson and Crick’s discovery of DNA’s double helix structure, the exhibition traces the major advances in human health, disease studies, ancestry and other natural sciences that have occurred since the genome project’s completion. It also looks ahead to how genomics will influence our lives as genetic sequencing becomes increasingly easy and inexpensive.
“Genomics is highly relevant, because it’s in the news every day, so people have a broad awareness of this topic, but almost no specific knowledge,” says Kirk Johnson, the Sant Director of the National Museum of Natural History. “You read the paper, and there it is, boom, but what does it mean when the police have my DNA? This exhibition helps to answer questions like this.”
In just the past few weeks, the Supreme Court ruled on two major decisions on genomic research: On June 3, the court ruled law enforcement could collect DNA from anyone who has been arrested. On Thursday, it then ruled naturally occurring human DNA could not be patented. Additionally, Angelina Jolie recently decided to get a preventative double mastectomy based on her predisposition to breast cancer as identified by genetic sequencing.
Genomics’ future raises major ethical questions surrounding human cloning, genetic engineering and prenatal genetic testing.
To address the array of complicated issues surrounding genomic research, the exhibition features four themed areas that cover what the genome is, how it relates to medicine and health, how it connects humans to all life and how it is part of each persona’s individual story. The displays are designed to be adaptable, with physical pieces and digital content that can be rearranged and replaced so that the displays can change as the field advances.
Johnson stresses the exhibition’s capacity to inspire the next generation of scientists who will have to come up with answers to genomics’ big questions. “Out of the millions of teenagers that will visit this exhibition,” he says, “some are going to walk in and go, you know, this is cool. We’re at the edge of this major biomedical revolution, and eighth graders, in 20 years, are going to be 32 -year-olds, and they’re going to be the ones prescribing our medicine. Science is often perceived as hard and boring in classrooms, so we want to break through that stereotype by making things fun and interesting.”
Eric Green, director of the National Human Genome Research Institute, believes the exhibition also will help assuage fears of genomics’ future. “Much of what people fear about genomic research is what they don’t understand,” he says. “So this exhibition gives visitors a foundation to think critically and in a more sophisticated way.”
“Genome: Unlocking Life’s Code” will be open in the Natural History Museum through September 1, 2014, after which it will travel around North America for about five years. To learn more about genomics, visit the exhibition’s website and check out Smithsonian Magazine’s own special report on the topic.
June 7, 2013
World Oceans Day often prompts reminders of all the terrible things that have already happened to the ocean and the even scarier prospects for the future. While there’s no doubt that all is not A-OK when it comes to ocean health, it’s worth remembering that when people have come together to make things better, they often succeed. These success stories span the globe and the gamut of marine habitats and organisms.
One of the biggest impacts people have had on Planet Ocean is through fishing and hunting. The Steller’s sea cow was exterminated a mere 27 years after its discovery in the North Pacific. Fortunately, protections have been put in place for many marine organisms, albeit sometimes just in the nick of time. North Atlantic right whale numbers are increasing, and the sea otter brings oohs and aahs from admiring tourists in northern California. Fish numbers have also often increased with protection, either through careful controls on harvesting methods and amounts or through the establishment of marine protected areas.
Sometimes our harvesting has destroyed the very habitat that the creatures we like to eat create. Oyster reefs once dominated shallow waters along much of the east coast of the U.S. But massive dredging efforts left muddy bottoms that new oysters can’t colonize, leading to a collapse of the populations of these magnificent bivalves who not only nourish us, but through their filtering clean the water where they live. In these cases, active restoration rather than simple protection has been required. This is sometimes harder than one might expect, but here progress is also being made.
Hunting and fishing are not the only things we do that can harm marine life. Declining water quality and other forms of pollution, such as the giant dead zone that forms off the mouth of the Mississippi each year, can also be a big problem. Once again, however, restrictions on what can be dumped into our waterways have resulted in dramatic turnarounds. Over a century ago, Monterey Bay was a mess, polluted by the industrial waste from the canneries on its shoreline. But now its ecosystem is restored—sustained and even thriving as a standout example of how public education programs and healthy tourism can have great impact. We still have a long way to go with plastic pollution, but communities around the world have started phasing out the use of plastic bags. China’s five-year anniversary of its ban on plastic bags has reportedly reduced consumption by 67 billion bags.
Ocean warming and ocean acidification loom as larger threats over the long term, and here successes are proving harder to achieve. But one of the important lessons of the last decade is that reducing local stressors can make a big difference, building the resilience of ocean ecosystems and buying us invaluable time as we figure out how to reduce the amount of carbon dioxide going into the atmosphere.
Bottom line? We need to think and act both locally and globally if we want to pass on a healthy ocean to future generations. In an era when catastrophes get much of the coverage, it’s important to remember that we can still make a difference. There are many successes to celebrate. Ocean conservation is working and we can learn from our successes. But there is plenty of work still to do.
May 28, 2013
Gaze at the stars this evening and you will see a rare phenomenon: three planets, all glowing so close to each other that it looks like they might bump. The trio—Venus, Jupiter and Mercury—actually are millions of miles apart, but on this special occasion their orbits are aligned with ours such that they appear side by side.
The Milky Way is home to an estimated 200 billion to 400 billion stars, and as many as 17 billion planets. Amazing things are happening around the cosmos every minute, but it is a treat when we can catch an unusual celestial event just by looking up, without even a telescope.
Tonight and in the coming months, a few of these events will be visible to the naked eye from any backyard in the United States so long as the sky is free of clouds. Be sure to mark your calendars—the events are fleeting, and occur at most once a year.
To make sense of these celestial happenings, we enlisted the help of Kimberly Arcand and Megan Watzke, authors of Your Ticket to the Universe: A Guide to Exploring the Cosmos, recently published by Smithsonian Books. Arcand and Watzke both work as communications officers for NASA’s Chandra X-ray Observatory, which means they have extensive experience dealing with the cosmos and capturing arresting astronomical images. The two have collaborated before on From Earth to the Universe and From Earth to the Solar System, two projects that bring the universe’s wonders down to earth in breathtaking photographs. Their new book features 240 full-color images from telescopes, observatories and in-space cameras, including the Hubble and Spitzer Space Telescopes and NASA’s Curiosity rover.
“You don’t need a medical degree to know when you’re sick or a doctorate in literature to appreciate a novel,” Arcand and Watzke write. “In the same spirit, even those of us who do not have advanced degrees in astronomy, astrophysics or space science can gain access to all the wonder and experience that the Universe has to offer.”
If this list whets your appetite for more exciting cosmological happenings, check out the book to learn far more amazing facts about the Universe, and peruse some of these lists of even more celestial events taking place this year.
Tuesday, May 28: Conjunction of Venus, Jupiter and Mercury
In celestial terms, “conjunctions” are when two or more objects appear really close together in the sky. On this rare night, Venus and Jupiter will come within 1 degree of each other, and Mercury, which has been close to the pair since Friday, will be within 5 degrees of them. According to NASA, the last time triple conjunction occurred in 2011, and another. won’t be seen until October 2015.
The three planets will be most visible 45 minutes to an hour after sunset. In the twilight, look west-northwest and low in the sky. Venus is the brightest of the three planets, and Jupiter will be close above it to the right.
Arcand and Watzke say:
Planets are always fun objects to try to find in the night sky. Because they are closer to us than the stars (other than the Sun, of course), they appear as tiny solid disks rather the just pinpricks of light. This means that the planets appear to be less affected by the blurring effects of our atmosphere, which is what causes the stars to “twinkle.” (But stars don’t actually twinkle. The movements of air and moisture in the Earth’s atmosphere makes the distant light look like it’s changing in ways that it is not.)
Venus and Jupiter are not actually any nearer each other than normal–they just appear to align from our vantage point on Earth. Venus is still closer to the Sun than the Earth, and Jupiter remains in its orbit as the fifth planet out at an average of about 500 million miles from the center of the Solar System.
Fun fact: Venus is often a great night sky viewing target and was long referred to as “the evening star” because of it’s clear and early appearance in the evening. So we’re often wishing on a planet and not a star if we wish up on the first bright light of the evening.
The biggest full moon of 2013! On Sunday at 7 a.m. GMT (that’s 3 a.m. in New York, midnight in Los Angeles), the moon will reach it’s closest point to earth of the year, a mere 221,824 miles away. That’s not quite close enough to touch, but it may look like it is.
Arcand and Watzke say:
As the Moon travels in its orbit around Earth, more or less of the Moon’s disk is illuminated by the Sun. When the Moon is behind the Earth with respect to the Sun, we can see its full face lit up by sunlight. This is what we know as the “full Moon,” and it occurs once every 27 days or so. Use the opportunity of a fully illuminated Moon—especially this big one—to get a really good look at our nearest neighbor in space. The pockmarks are the result of meteors that have struck the lunar surface. Because the Moon has essentially no atmosphere or weather like we do on Earth, these craters have been preserved in pristine condition instead of being erased like those on Earth largely have.
Fun fact: On the occasional times a full moon happens 13 times in a year, instead of 12, the last full moon is called a “Blue Moon”, which is where the phrase comes from.
Two major annual meteor showers, the Delta Aquarid and the Perseid, will be shooting across the night sky throughout most of July and August.
The Delta Aquarid Meteor Shower runs from July 12 to August 23, and peaks from July 27 to 28 with up to 20 meteors per hour. It comes from the debris of comets Marsden and Kracht. It is not highly visible in America, and best seen from the Southern Hemisphere and at low altitudes just north of the equator. Light from the moon, in its second quarter, will block most of the faint meteors from sight, too, but you should still be able to see at least some of the big ones if you’re on the lookout for them.
The Perseid Meteor Shower runs from July 17 to August 24, and peaks from August 11 to 12 with up to 60 meteors per hour. It is produced by comet Swift-Tuttle. Unlike the Delta Aquarid, it is highly visible in the Northern Hemisphere, and peaks during a first quarter moon, which means hardly any light will obstruct the show.
Arcand and Watzke say:
Meteor showers are great to plan summer evenings around. These showers happen when the Earth passes through a cloud of rocks from a comet that has been ripped apart by gravity. While many people want to use binoculars or telescopes in order to get the best views of events in the night sky, meteor showers are actually best viewed with just your eyes. That’s because binoculars or a telescope will limit your field of view. The game in watching meteor showers is to get the widest and darkest view of the night sky.
Fun fact: Despite their nickname of “shooting stars” in popular culture, these are not stars at all. Impress your friends and family by pointing out that these streaks of light are, in fact, pieces of rock and other debris whizzing through the Earth’s atmosphere.
May 8, 2013
The National Zoo’s two giant pandas have little interest in each other 11 months of the year. Mei Xiang, 15, and Tian Tian, 16, are solitary creatures, happy to spend most of their days chowing down and napping. But March was mating season. For 30 to 45 days, pandas undergo behavioral and physical changes that prepare them for an annual 24- to 72-hour window in which females ovulate, the only time they can conceive.
Just because they are able to mate, though, doesn’t mean they will. Mei Xiang and Tian Tian are what David Wildt, head of the Center for Species Survival at the National Zoo, calls “behaviorally incompetent.”
“Tian Tian tries really hard, and is very diligent in his duties,” he says, “but he’s just not able to pull Mei Xiang into the proper mating position.”
The pair is not alone. Of pandas in the United States today, only two, Gao Gao and Bai Yun at the San Diego Zoo, have been able to breed naturally. Captive pairs have succeeded elsewhere in the world as well—especially in China, the bears’ native home, where the captive population is much higher—but mating difficulties are still common. Panda’s total population, captive and wild, is about 2,000, so each failed match is a crucial missed opportunity for repopulation.
The species’ future is brighter than these mating difficulties suggest, though. Wildt is part of an international network of American and Chinese specialists—veterinarians, researchers and zookeepers—who have collaborated for years on improving captive panda breeding practices. In recent years, the team has made huge advances in understanding the bears’ biology and behavior, which has inspired new approaches to care that reduce faulty coupling, or even circumvent it.
Their studies are turning the tide. Today, the bears’ captive population is around 350, almost triple what it was 15 years ago.
When Mei Xiang began to ovulate on the last weekend of March, zookeepers closed the David M. Rubenstein Family Giant Panda Habitat to visitors, made sure she and Tian Tian were comfortable, then brought the lustful pair into the same room for the first time since last spring. The two had become rambunctious leading up to the encounter, and spent days staring longingly at one another through the fence that divides their yards. They had hardly touched their bamboo.
Despite the flirtatious fireworks, though—and while it was the seventh year in a row the two had been put together to mate—the two pandas again failed to copulate. As she has in the past, Mei Xiang flopped on her belly like a pancake when she met with Tian Tian—the opposite of good mating posture, which would have her rigid on all fours—and Tian Tian went about his usual routine of stomping around and standing on her, clueless what to do.
After multiple attempts, the keepers ushered the tired pair back to their separate yards.
Panda breeders’ challenge is overcoming unknown variables in the mating process, says Copper Aitken-Palmer, head vet at the Smithsonian Conservation Biology Institute. “There may be some developmental things that we are doing differently under human care, versus what they’re learning in the wild,” she says. Cubs often stay with their mothers for two or more years in the wild, for instance, so they might learn how to breed by watching or listening. Adults may need to mate with an experienced partner first to learn what to do. It’s hard to know for sure, Aitken-Palmer explains, because wild pandas are incredibly hard to observe in their bamboo-filled habitat in China’s southwestern mountains.
The National Zoo compensates for its lack of other pandas to mimic these conditions by preparing Mei Xiang and Tian Tian year-round for mating, both the act itself and the steps leading up to and following it. Since Mei Xiang arrived, she has been trained to receive injections, get blood drawn, milk and lie peacefully during ultrasounds, all without a fuss. (She even rubs the ultrasound gel over herself for her keepers.) The Zoo is trying to teach her to pancake onto a raised platform instead of the ground to make herself more accessible to Tian Tian, and also gives Tian Tian strengthening exercises so one day he might learn to pull her upright.
In China, zoos and breeding centers with a greater number of pandas use similar techniques to encourage coupling, and have begun to test the theory that pandas learn from observation by having cubs attend breeding sessions. On rare occasions, some Asian breeding centers have gone so far as to show their bears videos of other pandas mating—yep, panda porn. There’s no concrete evidence it works, though.
(Josh Groban has his own panda mating technique, but its success also hasn’t been confirmed.)
More than behavioral changes, the most significant improvements in breeding techniques have come at the chemical level. Researchers have developed increasingly accurate measurements of female pandas’ hormone levels and vaginal cell changes, and now are able to pinpoint the exact ideal time frame for a panda’s egg to be fertilized. This new-found accuracy not only dictates the best window to put two pandas together in the same room, but also dramatically improves the success of the practice that allows pairs who cannot figure out how to mate to have cubs anyways: artificial insemination.
“Because pandas’ reproductive activity is so infrequent, they don’t have many opportunities for sexual experimentation and figuring it out,” Wildt says. A panda in heat in the wild may mate with a number of males all competing for her, but those in America’s zoos are stuck with the one they’ve got, regardless of sexual compatibility. Artificial insemination is key to panda breeding, he explains, because it has allowed scientists to overstep the hurdle of sexual compatibility entirely. The technique, which deposits collected semen into a female while she is anesthetized, was “very rudimentary” in the early 2000s, in his words, but took off about seven years ago when scientists began to develop effective ways to freeze and store semen for multiple years and craft more precise tools, like tiny catheters that sneak through a female panda’s cervix to place sperm directly into her uterus.
So far in America, six panda cubs have been produced by artificial insemination, including two from Mei Xiang. That’s one more than the number of the country’s naturally conceived cubs—and as Wildt points out, those cubs all come from the same super-compatible couple in San Diego. (No exact data is available for China’s natural vs. artificial breeding stats, Wildt says, because its zoos often follow successful natural mating sessions with artificial inseminations the next day to improve the chances of fertilization.)
Artificial insemination is particularly valuable for America’s pandas, along with all others outside of China’s well-populated breeding centers, because it has the potential to increase genetic diversity, which is essential for maintaining the captive population’s health as it expands. Mei Xiang has been artificially inseminated every year she has failed to mate with Tian Tian since 2005. This year, for the first time, she was inseminated with semen from two males, first with a fresh-frozen combination of Tian Tian’s sperm, and 12 hours later with some of Gao Gao’s semen stirred in as well, shipped frozen from San Diego. “Artificial insemination gives us the opportunity to mix things up in the absence of multiple males,” Aitken-Palmer says.
According to Wildt, the National Zoo will continue to focus on artificial insemination for the foreseeable future. But natural breeding is the ultimate goal for the species, once zoos and breeding centers have large enough panda populations to depend on it, he says. The numbers are headed in the right direction; the bears are back to “self-sustaining,” which means no more giant pandas have to be brought into captivity, and scientists will have them under their care for at least the next 100 years. The Chinese are even beginning to reintroduce pandas into the wild (although with some difficulty).
“It’s really a great success story,” says Aitken-Palmer. “There aren’t many endangered animals we’ve been able to do this with.”
Now, everyone is waiting on Mei Xiang to add to the species’ growing numbers. Her first cub, Tai Shan, came in 2005, and the second, born last summer after years of disappointment, died from underdeveloped lungs after just six days. Another successful birth would help to heal the wounds of last year’s tragedy, says Juan Rodriguez, one of the National Zoo’s panda keepers.
It also would give Mei Xiang and Tian Tian’s Chinese owners a good reason to keep the pair together at the zoo instead of considering a different match, which has been an ongoing discussion.
Bandie Smith, the Zoo’s giant panda curator, says not to hold your breath for news on Mei Xiang’s pregnancy anytime soon. The staff might not know if Mei Xiang is pregnant until a cub pops out. Females build nests and cradle objects each year whether they are pregnant or not (the latter is called a “pseudo-pregnancy”), and the fetuses are so small that they often escape detection in ultrasounds. Pandas experience a phenomenon called delayed implantation, too, in which a fertilized egg floats around for a number of weeks—usually between 90 and 160 days—before implanting in the female’s uterus and beginning a short 40- to 50-day gestation period.
All this means that no one has a very exact idea of when a new cub would arrive—somewhere around mid-August, Smith says.
“Breeding pandas is a very protracted process, and it’s never a guarantee. That’s the frustrating part,” says Rodriguez. “The cool part is that you’re among people who are trying to keep a critically endangered species on the planet. If we can ensure their continuous path to recovery, then our great grandchildren could actually experience pandas in their natural habitat. You can’t beat that.”