by Sharon Oosthoek

Aboriginal rock paintings show that thylacines, or Tasmanian tigers, once lived all over Australia and on the islands of Tasmania and New Guinea. At the time, they were the largest meat-eating marsupials in the world. But then humans hunted them to extinction.

Benjamin, the last Tasmanian tiger, died in 1936 in Tasmania’s Hobart Zoo. That’s when zoo staff discovered the animal they thought was male, was in fact female. Their mistake was an easy one to make: both male and female Tasmanian tigers had pouches. Females raised their babies in the pouches, and males used them to protect their external reproductive organs. Tasmanian tigers’ scientific name, Thylacinus cynocephalus, actually means, “pouched dog with wolf head.”

Hunt and Be Hunted

While it was more related to kangaroos than wild dogs, the Tasmanian tiger had a dog’s body, a tiger’s stripes, and a muscular tail it used for balance. It could open its jaws a whopping 120 degrees. By comparison, a wolf can open its jaws about 90 degrees. Why such a big mouth? Thylacines were opportunistic hunters capable of taking down large creatures like kangaroos. They were strong hunters, but unfortunately that earned them a bad reputation.

“It was wrongly blamed in Australia for killing sheep,” says Andrew Pask, a molecular biologist at the University of Connecticut who studied the tigers. “People were really poor and were stealing each others’ sheep and blaming it on the Tasmanian tiger.” Because of these rumors, bounty hunters were given rewards to bring in dead thylacines. It didn’t take long before population levels dropped dangerously low.

Every few years since Benjamin’s death, people claim to have seen a Tasmanian tiger in the wild. In 2005, German tourists snapped photos of an odd creature that vaguely resembled a Tasmanian tiger. The blurry images inspired the imagination of those who want to believe the animals somehow survived extinction in Tasmania.

An Australian magazine, The Bulletin, offered $1.25 million to anyone who could capture a live, uninjured Tasmanian tiger. No one did, but the Tasmanian tiger was suddenly alive again in people’s imaginations…and so was its DNA.

A Mighty Mouse

In 2008, Dr. Pask led a team at the University of Melbourne in Australia that extracted a gene from a long-dead baby Tasmanian tiger. The baby had been preserved in alcohol for 140 years and kept in a museum. The gene they extracted was the thylacine’s blueprint for growing bone and cartilage, a tissue that acts like elastic to connect joints.

DNA is a bit like a set of instructions that tells a living organism how to grow. Each gene inside DNA contains instructions for specific characteristics, including the way bones, skin, and organs form.

Dr. Pask injected the thylacine gene into mouse embryos. As the embryos grew into adult mice, they developed bones and cartilage…without any apparent problems. That meant the Tasmanian tiger gene worked properly, long after the tiger had died.

“It’s important because we’d really like to understand how [the Tasmanian tiger] evolved its particular body plan,” says Dr. Pask. “We can look at the DNA and we can pick out the genes we think are important, but unless we put them into another living organism like a mouse, and see what they do, we don’t really know.”

Back in Order

In 2009, scientists from Penn State University studied some of the Tasmanian tiger’s genes using hair samples from two museum specimens. They successfully sequenced some of the animal’s DNA. That means they figured out the order, or sequence, of the instructions inside the genes.

Knowing the order of an animal’s genetic structure helps scientists understand how that animal is made — and it may even give some clues about why thylacines became extinct. “Tasmanian tigers were really interesting animals,” says researcher  Webb Miller. “It’s so sad they’re gone.”

Dr. Miller explains that by practicing on the Tasmanian tiger, he and his fellow scientists learned a lot about how to sequence the genes of other extinct species and species at risk of extinction.

The scientists have since found out that when a species is close to extinction, there is a noticeable lack of genetic diversity from animal to animal. When animals of the same species have slight differences in their genes, the species as a whole is able to fight off disease or adapt to dramatic environmental changes. But if their genetic code is the same, one disease can kill all of them. “Right now there are lots of cool animals teetering on the brink of extinction,” says Dr. Miller. He hopes that by breeding endangered animals with the widest possible range of genetic diversity, their babies might have a better chance of survival.

Tasmanian tigers may have disappeared 75 years ago, but they still have something to teach us today.

Mugshot:

Tasmanian Tiger

Size: About 60 centimeters at the shoulders

Weight: About 30 kilograms (65 pounds)
Color: Yellow-brown with dark brown stripes

Favorite food: Wallabies, wombats

Distribution: Tasmania, mainland Australia, and New Guinea
Last seen: Tasmania, 1936

Closest Relatives

Thylacines’ living cousins include numbats and small carnivorous marsupials called quolls, as well as the Tasmanian devil. Thylacines were not related to dogs or dog-like animals or tigers at all!

by Sharon Oosthoek

What plant is so menacing it’s an outlaw in the United Kingdom? If you move it across state borders in the United States without a permit, you’re in trouble? The answer is giant hogweed. The rock band Genesis even wrote a song about it threatening the human race in a plant-o-pocalypse scenario. (Yes, you can download the ringtone.)

“Everybody knows about yellow jacket wasp and bee stings,” says Jeff Muzzi, Manager of Forestry Services for Ontario’s Renfrew County, “but where things get a little more dangerous out there is with giant hogweed and [its relative] wild parsnip.”

The Burn That Lasts

Both plants can burn your skin, giving you blisters, and maybe leaving scars. Their sap contains chemicals called furocoumarins, which are phototoxic. That means the chemicals become active in the sun.

“After a day or two, your skin turns red and starts to blister. It’s ugly and can take up to a month to clear up,” says Muzzi. “But the photosensitivity (sensitivity to sunlight) will last for years. You won’t have any protection against the Sun — you’ll get instant sunburns every time you’re exposed.” If you’re unlucky enough get the sap in your eyes, you can go temporarily, or even permanently blind.

Settlers to North America brought wild parsnip with them from Europe over 100 years ago as a food source. Boil the roots and you have a nice starchy meal. Of course, the settlers knew enough to wear protective clothing at harvest time. Wild parsnip grows a bit taller than a mailbox and is topped with small clusters of yellow flowers.

Today, wild parsnips are everywhere, especially in roadside ditches and meadows. Giant hogweed, thankfully, has spread more slowly. Originally from the Caucasus region between Southwestern Asia and Europe, people brought them to North America because they thought they were pretty and liked to have them in their gardens. Giant hogweed stems reach up to five meters — that’s taller than a one-storey building — and are crowned with large umbrella-shaped cluster of small white flowers.

Painful Plants Aplenty

Plants can also cause you pain in more obvious ways — with sharp thorns and barbs for example. Botanists (scientists who study plants) call this a mechanical defense.

Roses and cacti have mechanical defenses. While their thorns can puncture your skin and make you bleed, you’ll easily recover unless your wound gets infected.

A more sneaky strategy is something botanists call a chemical defense. In this case, the liquid on a plant’s leaves or stems contains toxic chemicals that react with your skin, whether or not you expose it to the sun. Poison ivy, oak, and sumac all use a chemical defense by spreading an oily liquid called urushiol. (Well, it’s probably an accidental defense against humans since deer, goats, horses and birds eat parts of the plant.)

Urushiol is very sticky and doesn’t dry, so it clings to anything that touches it — skin, clothing, and pet fur. Even breathing in the smoke of a burning poison ivy, oak, or sumac can make your eyes and nasal passages red and tender. But if you touch poison ivy, you may not realize it until the next day, says environmental chemist, William Schlesinger, president of the Cary Institute of Ecosystem Studies in New York.

“You will wake up with a mild case of fluid filled blisters, which are extremely itchy and you can’t help but scratch,” he says. “That breaks the blisters and spreads the fluid across your body. If it’s bad, the blisters will coalesce (come together) and the entire surface of your skin will fall off and you’re left with one big, open, oozing sore.”  Eewww.

Unfortunately for the 80 percent of us who develop rashes from poison ivy, Dr. Schlesinger and other scientists have figured out the plant will get better at causing harm as we pump more carbon dioxide (CO₂) into the air. CO₂ is released by power stations that make electricity and comes out of the tailpipes of our cars, and it is causing the climate around the world to change.

Dr. Schlesinger and his team figured out the effect on poison ivy by buying CO₂ from a fertilizer factory and pumping it into a patch of forest in North Carolina until it reached levels scientists expect by 2050. They studied the forest from 1997 to 2004 and found the poison ivy grew faster and bigger, and its urushiol was more powerful. Ouch!

 Why urushiol?

Plants around the world contain the chemical urushiol. It’s purpose might have less to do with defense and more to do with protecting a plant’s wound.

 OW! Factor: OUTRAGEOUS plants

 • The manchineel tree’s sap, bark, and leaves are all highly toxic. It produces a sweet-smelling fruit that looks a lot like a crab apple, but don’t touch, and absolutely don’t eat. It contains a chemical that causes terrible pain and swelling.

Merely standing under the tree while it’s raining will cause your skin to swell and blister painfully. The tree grows in the Bahamas, the Caribbean, Central and South America, and in some parts of Florida.

• The giant stinging tree and the gimpie-gimpie are related trees that both grow in Australian rainforests and have large soft leaves covered in little hairs. The hairs contain a neurotoxin (a poison that affects nerve cells), and they can slide into your skin, delivering a sting that some people say is as painful as being scalded with boiling water and can last for months. You can even get sneezing fits just by standing next to a gimpie-gimpie.

By Sharon Oosthoek

July 13, 2011

If you looked at the plastic in your sneakers under a high-powered microscope, it would resemble cooked spaghetti, with each noodle tangled in the others.

Plastics are made of groups of many atoms — the smallest building block of any element — linked together into molecules. Molecules, in turn, are the smallest complete unit of any chemical. In plastics, the molecules are linked into long chains called polymers.

Polymers “become entangled with each other much like a single strand of cooked spaghetti gets tangled up with other spaghetti strands in a bowl of pasta,” explains Annette Jacobson, a chemical engineer at Carnegie Mellon University in Pittsburgh.

That entanglement makes it hard to break plastic, which is a good thing when it’s in your sneakers, toothbrush, bike helmet or hundreds of other products we use every day. But plastic’s strength is also its weakness — at least when it comes to the environment.

The reason: Plastic takes years, sometimes centuries, to completely disintegrate. So our garbage dumps fill up with discarded plastic — bags, food containers, tattered soccer balls and, yes, even old sneakers.

Full story

April 26, 2011

SHARON OOSTHOEK

Blame it on Augusta and the advent of colour television. Up till then, most golfers were content to play around the odd weed and didn’t get overly upset if skunks dug up turf.

But starting in the late 1960s, colour broadcasts of the Masters Tournament at the Augusta National Golf Club in Georgia showed the world a meticulously-maintained course shimmering like an ethereal Emerald City. Golfers turned green with envy.

“We call it the Augusta syndrome,” says Rob Witherspoon, director of the University of Guelph’s Turfgrass Institute and Environmental Research Centre. “The expectation of standards used to be lower. Golfers saw that and said ‘Why doesn’t our golf course look like that – blemish-free, no weeds?’”

But such standards come at a cost to the environment. Fertilizers, pesticides, herbicides and astounding amounts of water are all necessary ingredients.

(more)

March 11, 2011

By Sharon Oosthoek

Sockeye salmon with the most arduous spawning journeys have the strongest hearts, an adaptation that may better their odds of surviving projected rises in water temperature, say B.C. researchers.

Full story

Area to become marine conservation area

By Sharon Oosthoek

Last summer was a stressful time to be the mayor of Grise Fiord, a tiny hamlet on Nunavut’s Ellesmere Island. Meeka Kiguktak was keeping tabs on a research vessel motoring to Lancaster Sound to conduct seismic testing. Kiguktak and others in Grise Fiord and nearby communities were worried that the federal government scientists aboard would discover oil and gas deposits, putting an end to a proposed marine conservation area for the sound, which is sandwiched between Baffin and Devon islands.

Full article

March 11, 2011

By Sharon Oosthoek

It’s not every day emergency response experts gather to test their readiness to deal with a fish.

But the Asian carp is no ordinary fish, and so on Friday, a boardroom in the Peterborough offices of the Ontario Ministry of Natural Resources (MNR) is being turned into a temporary war room of sorts. It marks the first time government experts have come together to simulate an invasive-species emergency.

“We’ve run emergency-preparedness exercises before for influenza outbreaks,” said Eric Boysen, director of the MNR’s biodiversity branch. “We’ve done them for ice storms. We said we want to run one for Asian carp.”

Full story

March 9, 2011

By Sharon Oosthoek

A mysterious resurgence of phosphorus in the Great Lakes is endangering the aquatic food chain and human health, says a binational agency that advises Canada and the U.S.

Fifteen years after the last programs to control phosphorus runoff ended, the International Joint Commission urged on Wednesday a renewed effort to get the oxygen-depleting chemical out of the water.

The call to action was one of 32 recommendations the commission made to both governments in its biennial report on the state of the Great Lakes at Detroit’s Wayne State University.

Full story

February 3, 2011

By Sharon Oosthoek

A water flea about the size of the equal sign on a keyboard has more genes than any other creature analyzed so far, say scientists, who suggest its sophisticated genome could one day double as a highly sensitive and inexpensive environmental monitoring tool.

Vaccinating prairie dogs may be the key to saving rare black-footed ferrets

by Sharon Oosthoek

Behind the brick walls of the National Wildlife Health Center, past security doors leading to an isolation room, black-tailed prairie dogs dine on peanut-butter-flavored pellets. These tan-colored rodents with black-tipped tails were captured near Wall, South Dakota, and now live in burrows of stainless steel boxes connected by plastic pipes. Normally, they would be eating alfalfa pellets, carrots and broccoli. But on this summer day in Madison, Wisconsin, the only thing on the menu is peanut butter snacks, served up by the center’s scientists.

The prairie dogs—13 in all—gobble up the new offering and that’s good news because the pellets contain a vaccine against plague. Three weeks from now they will be exposed to Yersinia pestis, the bacterium that causes the deadly disease. Remarkably, nine of them will live.

The vaccine-laden pellets are the handiwork of U.S. Geological Survey (USGS) epizootiologist Tonie Rocke, who believes they hold the key to saving an animal once thought extinct.

Full story