24 Jul 2015

Longing for the Giants

By Claire Eamer

In the long and complex story of evolution, organisms emerge and then disappear, never to be seen again. I understand and accept that. Honest. But, fair or not, I regret the loss of some organisms more than others.

I admit it. I miss giant ground sloths.

Don’t get me wrong. I’m not old enough to have met a giant ground sloth face to face. None of us is. The last lingering remnants of a great bunch of animals perished about 5,000 years ago, probably on a small Caribbean island.

Fossil foot of a Jefferson's ground sloth beside my shoe. C. Eamer photo.

While they were here, though, they were amazing. And really, really big. Well, some of them were big. Some species were as small as house-cats, but the largest ground sloths – Megatherium and Eremotherium – were the size of elephants. Hairy elephants, with thick hides dotted with bony plates, claws the size of bananas, and a propensity to stand up on their hind legs and maul substantial trees.

If it’s any comfort, they were vegetarian. Mostly. Some scientists think that Megatherium, at least, might have used those giant claws to grab a bite of meat to go with the veggies, especially when climate change dried the local landscape and thinned out the forests it relied on.

Greg McDonald, senior curator of natural history for the US National Park Service, is another sloth enthusiast. He recently delivered a talk on ground sloths, via Skype, to an appreciative audience in Whitehorse, Yukon.

The Yukon is, surprisingly, ground sloth territory. It’s actually where I first met a ground sloth – if not face to face, then at least face to skull. It was a Jefferson ground sloth, a member of the genus Megalonyx, and its ox-sized skeleton looms over visitors to the Beringia Interpretive Centre in Whitehorse.

For hundreds of thousands of years, Megalonyx ranged from southern Mexico to as far as Alaska and the northern Yukon. Megalonyx was unique, McDonald said, in being a wholly North American sloth. Although its ancestors came from South America, Megalonyx itself evolved in North America and never spread south of Mexico.
A sloth skeleton towers over visitors to the Beringia Interpretive Centre. C. Eamer photo.

That made it a late-comer in the sloth world. Like many other strange and wonderful mammals, sloths evolved in South America, in splendid isolation.

“For most of the age of mammals,” said McDonald, “South America was an island continent, much as we think of Australia today.”

The giant Megatherium roamed the ancient forests of South America in those days. And it had a curious assortment of cousins: anteaters, giant armadillos, and a bizarre creature called a glyptodont that looked like an ambulatory bone igloo. They all belonged to a group called Xenarthrans, which evolved exclusively in South America.

Once thought to be an odd evolutionary offshoot, Xenarthrans are now recognized as one of the major subdivisions in mammalian evolution, McDonald said. They prospered for tens of millions of years in South America and moved on to North America when the Isthmus of Panama began to form and link the two continents, just a few million years ago. (Or maybe more than a few million years ago, according to some recent studies.)

That was a momentous time in evolution, said McDonald. It’s called GABI: the Great American Biotic Interchange. Released from isolation, the Xenarthrans drifted northward, along with other distinctly South American animals, such as giant flightless birds with the hooked beaks of meat-eaters and the ancestor of the humble porcupine. At the same time, animals that had evolved in North America moved southward, including hunting cats with dagger-like fangs and those members of the camel family that became South America’s llamas and alpacas.

Ground sloths spread and adapted and changed on both continents for several more millions of years. They even took to the sea. Marine deposits in southern Peru have turned up a wealth of ancient fossil whales, seals, and sea lions – and entire skeletons of giant sloths. The sloth skeletons show clear evidence of adaptation to an aquatic environment. McDonald said it appears that the aquatic sloths were evolving into animals that went into the sea to eat sea grasses. Like the whales, they were reversing the classic sea-to-land journey of most mammals.

But that’s as far as they got. The aquatic sloths died out about 4 million years ago, and most of the rest of the ground
sloths didn’t survive the great megafauna die-off at the end of the last glaciation, about 12,000 years ago. A few small ground sloths lingered on isolated Caribbean islands, where 5,000-year-old sloth bones have been found in caves.

Today, the much-diminished sloth tribe has been reduced to the endangered tree sloths – a mere six species in two genera – eking out an existence in the shrinking rainforests of South and Central America.

The giants are gone. And, even though I never shared the world with them, I miss them. In fact, they inspired me to write my first kids' science book, Super Crocs & Monster Wings: Modern Animals' Ancient Past.

18 Jul 2015

Learn Latin Names of Common Plants

By Helen Mason

A recent trip to Ireland reinforced for me the importance of learning Latin names of common plants.

Of course I recognized my old friend Taraxacum sighted here at Mellifont Abbey in County Louth — and in numerous fields. Although we in North America don't think of dandelions as an invasive species, they are native to Eurasia and have been spread around the world by settlers who likely planted the seeds to make use of the plant's many medicinal and nutritional uses.

Dandelion at Mellifont Abbey. (Helen Mason photo)

I also knew that this bird fishing in the waters outside Ashford Castle in County Mayo had to be a member of the heron family. It's a grey heron (Ardea cinerea), a species native to temperate parts of Europe, Asia, and parts of Africa.

The herons around my Georgian Bay cottage are great blue herons (Ardea herodias) — same genus, different species.

Grey heron fishing in County Mayo. (Helen Mason photo)

What puzzled me, however, was a flower I found while exploring County Clare's Craggaunowen, a tourist site with re-creations of the various types of housing used in Ireland's past — from a Crannog or lake-dwelling from the Bronze age, to a ring fort from the 4th and 5th Centuries, to 1400s-era castle.

Walking through the woodlands below the fort, I admired this blossom.

The Irish jack in the pulpit: Arum maculatum. (Helen Mason photo)

Not recognizing it, but thinking it might be related to something I did, I asked the guide.

"Jack in the pulpit," she responded, "sometimes called lords-and-ladies."

This is where common names can run us into trouble. To me, a jack in the pulpit is a shy blossom that covers is reproductive parts.

The Canadian jack in the pulpit: Arisaema triphyllum. (Helen Mason photo)

In fact, these two jack in the pulpits belong to the same family but not the same genus or species.

The Irish plant is Arum maculatum, a woodland species common to Europe, Turkey, and the Caucasus. Like many plants, it has a number of common names — snakeshead, adder's root, Adam and Eve, and lords-and-ladies, as well as jack in the pulpit.

The Canadian plant is Arisaema triphyllum, a native of moist eastern North American woodlands. Like its Irish distant relative, this jack in the pulpit has other names, including bog onion, brown dragon, Indian turnip, and American wake robin.

Common names change from locale to locale. They can provide interesting information about the use of the plant or the social history of the namer. The Latin term is unique. It identifies one genus and species, and only that one.


10 Jul 2015

The Best Dog-gone Study Ever!

free vector Cartoon Dog clip artPost by Helaine Becker


Do you love dogs?

Of course you do.

How 'bout science?

Yes,  you love science too.


Then you will double-dog love this new Citizen Science project that you - and your dog - can participate in!

It's easy - all you have to do is wait for your dog to poop. Then stoop, scoop - and mail that poop to Oregon State University.
cute%20dog%20clipart
Yes, you read that right.

Researchers at the university would be most grateful if you mailed samples of your pet's poo to them for a study on dog microbiomes. They want to find out what's going on inside dogs' guts, and what mini-critters live in there. And the best way to figure it out is by looking at pooches' poo under the microscope. Lots of poo.

So go, ahead, stoop for science! You can find all the deets  on how you and your dog can enroll here.

Not a fan of 'pooping a letter' in the mailbox?  You can still participate in great dog-related science investigations. You'll find many other research studies, some as easy as answering a dog-related quiz, at the Dog Science Group.







<a href="http://cliparts.co/clipart/2939649">cliparts.co</a>

3 Jul 2015

Ostrich Oddities and Fun Facts

Baby ostriches - photo by Mink
By Marie Powell

An ostrich is the largest bird alive today, with adults reaching sizes of over nine feet tall. Ostrich chicks are already a foot tall -- as tall as a school ruler -- when they hatch. A wild ostrich can only be found in Africa now, although they're raised on farms in North America and around the world.

Wouldn't it be wonderful to go ostrich-watching on a safari to Africa? The next best thing is an "armchair safari" though books and websites. I found out a lot about ostriches and their habits while researching my children's science book, Meet a Baby Ostrich (Lerner Group, 2015).

For example, an ostrich also lays the largest bird egg, averaging about seven inches long and 3.5 pounds in weight.

Ostrich head - photo by A. Kniesel
Their large eyes are amazing, with long lashes to protect their eyes. With their keen eyesight, they're favourites at the watering hole, often warning other animals if predators are near. These flightless birds have soft feathers on their backs but bristly feathers on their necks and heads -- and their legs are bare.

They're also omnivores, chowing down on seeds, shrubs, fruits, grass, insects, and even small lizards. Like most birds, they swallow pebbles to help them digest food. They can survive for several days without water.

Here are a few suggestions for more information:
  • Can You Tell an Ostrich from an Emu? by Buffy Silverman (Lerner 2012)
  • Ostrich: The World’s Biggest Bird by Natalie Lunis (Bearport 2007)
  • Baby Birds by Bobbie Kalman (Crabtree 2008)
  • National Geographic: Ostriches  
  • American Ostrich Association: Facts
  • Check out Margriet Ruur's safari to Africa in Elephants for Lunch
  • Also check out other African-related publications and websites on our Sci/Why post, "Who Wants to be a Scientist?"
Meet a Baby Ostrich by Marie Powell
Available from Lerner Group, 2015


Marie Powell is the author of more than 30 children's books, including Dragonflies are Amazing (Scholastic Canada, 2007) and Meet a Baby Ostrich (Lerner Group, 2015).

26 Jun 2015

Saskatoon Offers Robotic Cow Massagers, Big Physics and More


By Pippa Wysong (June 26, 2015)

TORONTO – From robotic cow massagers to photon accelerators and big physics, to a major vaccine development centre, Saskatoon is a hub of science, discovery and outreach.  This, of course, was a delightful find for the nearly 100 members of the Canadian Science Writers’ Association (CSWA) who attended the annual conference there. We couldn’t get enough of what the University of Saskatchewan had to offer.

The first stop on campus was the Rayner Dairy Research and Teaching Facility, home to about 100 cows where research is done looking at how feed combinations affect milk production, the use of robotic technology, cow health, fertility and more. Between that and the Ryan-Dube Equine Performance Centre, veterinary college students learn how to work with big animals.

We saw cows, ready to be milked, wander into an automatic milking stall. A cow walks in, had treats she could snack on, and stands there while milking cups attach themselves to her udders – guided by a robotic vision system. When done, the cow we watched languidly walked out.

Next to this was a robotic arm in the form of a large spinning brush that could be activated by a cow to get a back-scratch or massage. And just as our guide was describing how cows voluntarily walk over to the device and activate it, one did. It was a bovine spa moment.

Devices like these are starting to appear in actual dairy farms because, well, the cows like it, according to Dr. Bernard Laarveld who teaches animal and poultry science. He noted that when outside, cows often rub their backs or sides against a fence or tree. It feels good. Mimicking this indoors makes cows happy.

We also toured the Canadian Light Source (CLS) where several physicists described their projects, ranging from using the synchrotron for medical diagnostics, to soil analysis. The ranges of light frequencies it uses means it is one of the most sensitive tools in Canada for analysing the structure and chemistry of materials, including soil, metals and biologic materials.

Impressively, the public can request tours for both the Rayner centre and the CLS.

GMOS
Being in the agriculture research capital of Canada, the topic of GMOs came up. A keynote talk was given by Mark Lynas, a former anti-GMO food activist who was behind various campaigns ripping GMO crops out of fields, in England. He now regrets the activism.

Why? The AAAS - The American Association for the Advancement of Science released a consensus statement saying climate change was real and that the science overwhelmingly demonstrated it. He was impressed with the science. But then the AAAS released a consensus statement saying GMOs are safe, and generally good for farming and for feeding the world's population. He couldn't support the one on climate change, and not the one on GMOs since the quality of the science was excellent for both, he said. During his activism days, he says he didn’t know the science.

The group got the chance to meet numerous other scientists at the conference in areas ranging from Arctic water quality, soil science, a researcher comparing heritage vs modern wheat, global food security, vaccine development, and more. And there was a public talk by Jay Ingram about Alzheimer’s Disease (he also gave a talk on effective and creative story-telling methods).

PROFESSIONAL DEVELOPMENT
What about the art of science communication? Speakers from Mashable, Greymadder.net and the CBC gave inspiring talks about new ways of presenting stories and the changing market place. Personal stories still matter when it comes to what people want to read, said Alix Hayden who launched Greymadder. Professional development sessions were useful for beginner and seasoned science writers alike.

There was fun too, such as the boat tour on the Saskatchewn River on a perfect day. We mingled with researchers working on how to deal with the effects of climate change (such as drought) and managing this valuable river source – the water of which is needed for most of Canada’s crops. These world-class researchers are also working as consultants in China and advising how to reduce emissions and water pollution there – much of which eventually flows to Canadian waters.

With a population of only 250,000, the city of Saskatoon sure packs in a lot of world-class science.

-30-