September 15, 2010
Just how long has the world’s oldest living thing been on this planet? That would be Siberian actinobacteria, and they’ve been here for some 400,000 to 600,000 years, longer than our species has existed.
Photographer Rachel Sussman is keeping track of these ancient specimens. She’s been photographing organisms that are 2,000 years old and older around the world (nicely mapped out here). There’s the world’s oldest predator (also the biggest), the 2,400-year-old Armillaria fungus in Oregon, which kills trees. And a 2,000-year-old brain coral off the coast of Tobago. And a clonal creosote bush that’s been living in the Mojave Desert for 12,000 years.
Sussman is blogging about her adventures. She’s currently in Sicily, trying to figure out the age of an ancient chestnut tree. She estimates she’s got maybe two more years to go on the project. Why spend so much time photographing old things? She explains in her recent TEDTalk (above):
The oldest living things in the world are a record and celebration of our past, a call to action in the present and a barometer of our future. They’ve survived for millennia in desert, in the permafrost, at the tops of mountains and at the bottom of the ocean. They’ve withstood untold natural perils and human encroachments, but now some of them are in jeopardy, and they can’t just get up and get out of the way. It’s my hope that, by going to find these organisms, that I can help draw attention to their remarkable resilience and help play a part in insuring their continued longevity into the foreseeable future.
I look forward to seeing what she makes of the project.
July 30, 2010
Many of the poster animals of Australia—kangaroos, koalas, wombats and wallabies, to name a few—are marsupials, animals best known for carrying around their young in a pouch. Marsupials can also be found in the Americas; in the United States, the Virginia opossum is the only one, but there are dozens of species in Central and South America.
Scientists trying to draw the marsupial family tree have been perplexed by contradictory evidence: DNA studies suggested that the Australian branch was an offshoot of South American animals that migrated to Australia when the two continents were connected and part of Gondwana. Fossil studies, though, seemed to show that some of the Australian marsupials had made their way back to South America.
In a new study in PLoS Biology, researchers from Germany set out to make a marsupial family tree using retroposons, a kind of jumping gene—pieces of DNA that are copied and pasted at random within the genome. The more closely related two species are, the more retroposons they will share.
Comparing the retroposons of the 21 marsupials showed that they all shared 10 jumping genes, thus confirming that they shared one ancestor. But the South American and Australian marsupials formed distinct groups; the Australians shared retroposons that their South American relatives lacked. The researchers were also able to determine that the South American branch was older (meaning that the Australian marsupials had come from South America) because the South Americans lacked two retroposons shared by everyone in the Australian branch.
Check out the entire collection of Surprising Science’s Pictures of the Week on our Facebook page.
November 10, 2009
While writing about the Falklands wolf and the Labrador duck, I was reminded that they are only two of the dozens, maybe hundreds, of creatures that have gone extinct in recent human memory (that is, the last few hundred years). Here are seven more creatures that exist only in pictures or as museum specimens:
Dodo (Raphus cucullatus)
The dodo has become synonymous with extinction. To “go the way of the dodo,” for example, means that something is headed out of existence. The three-foot-tall, flightless bird lived on the island of Mauritius in the Indian Ocean. They probably ate fruit. Though the birds did not fear humans, hunting was not a huge problem for the birds as they didn’t taste very good. More troublesome were the other animals that came with people—like dogs, cats and rats—that destroyed dodo nests. Human destruction of their forest homes was also a contributor to the dodo’s decline. The last dodo was seen on the island sometime in the late 1600s.
Steller’s sea cow (Hydrodamalis gigas)
Georg Steller first described his sea cow in 1741 on an expedition to the uninhabited Commander Islands off the coast of Kamchatka. The placid sea creature probably grew as big as 26 feet long and weighed around 8 to 10 tons. It fed on kelp. Just 27 years after Steller’s discovery, however, it was hunted to extinction.
Great auk (Pinguinus impennis)
Millions of these black-and-white birds once inhabited rocky islands in some of the coldest parts of the North Atlantic, where the sea provided a bounty of fish. Though their population numbers probably took a hit during the last Ice Age, it was the feathers that kept them warm that led to their downfall. The soft down feathers were preferred pillow filling in Europe in the 1500s and in North America in the 1700s. The dwindling birds were further doomed when their eggs became a popular collector’s item. The last live auk was seen in Newfoundland in 1852.
Passenger pigeon (Ectopistes migratorius)
The passenger pigeon was once the most numerous bird species in North America, making up 25 to 40 percent of all birds on the continent. There were as many as 3 to 5 billion of them before the Europeans arrived. They would migrate in huge flocks consisting of millions of birds. In the 1800s, however, they became a popular food item. Tens of thousands could be killed in a day. By the end of that century, when laws were finally passed to ban their hunting, it was too late. The last wild bird was captured in 1900. Martha, the last of her kind, died in 1914 at the Cincinnati Zoological Garden.
Carolina parakeet (Conuropsis carolinensis)
The eastern United States once had its own native parrot, the Carolina parakeet. But farmers cut down their forests and made fields, and then killed the birds for being pests. Some birds were taken so that their feathers could adorn ladies’ hats, and others became pets. The last wild parakeet was killed in 1904 in Florida. The last captive bird, which oddly enough lived in the same cage in which the passenger pigeon Martha died (above), died in 1918.
The thylacine wasn’t really a tiger, though it got that name for the stripes on its back. The largest carnivorous marsupial, it was once native to New Guinea, Tasmania and Australia. It had already become rare by the time Europeans found Australia, confined to the island of Tasmania. In the 1800s, a bounty was put on the species because it was a danger to the sheep flocks on the island. The last wild thylacine was killed in 1930, though some may have survived into the 1960s.
Golden toad (Bufo periglenes)
They lived in the Monteverde Cloud Forest Preserve in Costa Rica. Most of the year, they were hard to find, and scientists think they may have lived underground. But during the rainy season of April to June, they would gather in small, temporary pools to mate. The population crashed in 1987 due to a bad patch of weather and none have been seen since 1991. No one is sure what happened, but climate change, deforestation and invasive species have all been suggested as possible culprits.
July 14, 2009
Would you like to have an animal, plant or other organism named after you? Do you long to be immortalized in the faux-Latin of a species’ scientific name? Here are a few easy options:
You can discover one and name it yourself.
A colleague, friend or family member might have enough new species lying around and be willing to name one after you.
If you have enough money, you could pay an institution or charity to give a species your name. The Scripps Institution of Oceanography last year offered naming rights for several ocean species, starting from the rock-bottom price of $5,000.
But naming a creature after a person seems to lack a certain amount of creativity. After all, the rules for naming species are surprisingly open: The name must not be offensive, must be spelled in only the 26 letters of the Latin alphabet and may be derived from any language. In fact, a name need not be derived from anything at all; the rules state that an arbitrary combination of letters is also perfectly acceptable. (In contrast, astronomical bodies—like stars, asteroids and planets—have strict naming conventions overseen by committees.) So why shouldn’t a biologist have some fun when naming something she discovered?
Fictional characters (Han solo) have been honored, as have imaginary places (Dracorex hogwartsia). Unsurprisingly—since we are dealing with scientists—the genre of science fiction and fantasy seems to be a big draw, with the works of J.R.R. Tolkien a popular source (Gollumjapyx smeagol, Oxyprimus galadrielae, Macrostyphlus frodo and M. gandalf).
Some scientists turn to mythology, including Greek (Cassiopeia andromeda) and Norse (Clossiana thore).
Religion is another great source for names. There are species named for Indian gods (Stegodon ganesa), Egyptian gods (Papio anubis) and even a host of Aztec gods (Alabagrus coatlicue, A. ixtilton, A. mixcoatl and A. xolotl). The Christian devil has whole genuses named after him (Lucifer, Mephisto and Satan). And there’s even Noah’s Ark (Arca noae).
For those who like wordplay, there are anagrams (Rabilimis mirabilis), palindromes (Orizabus subaziro), rhymes (Cedusa medusa) and puns galore (Agra phobia, Gelae baen, Ytu brutus and Pieza pi).
Some names are clever only in translation, such as Eucritta melanolimnetes, which can be roughly translated as “the creature from the black lagoon.” Others only make sense if you know they derive from a misspelling. The genus Alligator, for example, derives from “el lagarto,” Spanish for “the lizard.”
Geography is an obvious source (Panama canalia), but there are a number of species whose names don’t seem to match their range. There’s the Australian death adder named Acanthophis antarcticus and the Tahitian blue lorikeet, Vini peruviana.
But sometimes people just run out of ideas. When one scientist reached his ninth species of leafhopper, he named it Erythroneura ix. And one early 20th-century biologist found so many species of olethreutid moths that it seems to have strained his creativity. A sampling includes: Eucosma bobana, E. cocana, E. dodana, E. fofana, E. hohana, E. kokana, E. lolana and E. momana. You get the idea.
Maybe he ran out of people he liked enough to give them a moth. I wouldn’t mind, though, having one named after me. And unlike Carl Zimmer and Neil Young, my last name lends itself perfectly to scientific nomenclature.
May 29, 2009
This microscopic shell comes from a snail, Opisthostoma vermiculum, found in a limestone hill habitat in Malaysia. Its morphology is unique, twisting around four different coiling axes, the most for any gastropod. “In addition, the whorls detach three times and reattach twice to preceding whorls in a fairly consistent manner, which suggests that the coiling strategy is under some form of strict developmental-gene control.”
This snail made the list of the top ten new species described in 2008, as decided by the International Institute for Species Exploration at Arizona State University and an international group of taxonomists. Others, which can all be found online here, include caffeine-free coffee, the ghost slug, a bacterium found in hairspray and the world’s longest insect.
Credit: Courtesy of Reuben Clements/World Wildlife Fund for Nature-Malaysia