"Effect of Activities on Bones" -- an excerpt from The Paleolithic Revolution

Stories from the Stone Age fascinate many people. Who were the long-ago humans who made cave paintings and carved ivory? I've often wondered how they turned rocks like flint or obsidian into knives and tools. The things that scientists learn from a scrap of bone, or an old carving, are amazing!

This year I got to put to use all my favourite archaeology facts while writing a book for Rosen Publishing, called The Paleolithic Revolution. It's part of a series called The First Humans and Early Civilizations.

Here's an excerpt from the first chapter, with the heading "Effect of Activities on Bones."

Bones are a lasting record of our lives. During the Paleolithic Revolution, modern humans were strong people. Their bones had much larger muscle attachments than is common today, even for professional athletes.

Their bones were harder, too. Bones from people born today are on average 15 percent weaker than bones from people born during the Upper Paleolithic Era. This is due to two factors. People today are less physically active and use more kinds of tools. Physical strength is less important for survival. People then spent a lot of time walking, gathering food, and hunting. Leading active lives and using simple tools made their muscles and bones strong, just as it does for athletes and construction workers today.

Paleolithic humans used their bodies as tools, putting stress and strain on their bones and joints. As people aged, their joints and backs wore out and became damaged. Bones broke from falls or fights, causing injuries like a rodeo rider would have today. Some breaks healed well, showing signs of good care. People broke their toes because their shoes were simple wraps or soft like moccasins, not rigid-sole boots. Their feet and toes were shaped from wearing sandals or soft skin shoes, instead of splaying wide from going barefoot all the time.

Paleolithic people’s lives affected their teeth, too. From chewing tough food, their jaws grew a little bigger than people today who eat softer food. Bigger jaws meant fewer impacted wisdom teeth than today. Their teeth had fewer cavities than today, too, because they ate fewer grains and other food that sticks to the teeth. But they had other tooth problems instead. Since people used their teeth as pliers and clamps, their teeth got worn down, chipped, and even cracked. People also chewed leather to make it soft. Some old people had teeth worn down to nubs.

Forensic Science: Not As Seen On TV

by L. E. Carmichael

Why do TV shows have science consultants when they clearly don't listen to what their consultants tell them?

I have often wondered this. Generally while watching forensics procedurals.

I still haven't recovered from that episode of Bones where Dr. Jack Hodgins, in shocking defiance of sterile protocol, sorts through a fecal sample and then grabs a lamp with his dirty glove. GAH!

The one that really gets me, though, is "zoom and enhance," a ubiquitous trope so blatantly impossible that every seventh grader in every class I've ever visited knows it could never happen. As does anyone who's tapped on a cell phone pic and watched it pixilate.

(I have a friend who does special effects for these shows. He HATES "zoom and enhance," because he's the guy that has to stitch together the distance shot and the completely separate close shot to make it look like that actually works.)

Lighten up, Lindsey, you say - these shows are for entertainment, not education! Thing is though, a lot of viewers, particularly young ones, don't make that distinction. And the inaccuracies in television dramas create misconceptions about how forensic science works in the real world.

Case in point, the CSI Effect. Many lawyers and judges contest that watching TV crime shows has biased jurors' reactions to evidence presented in real trials. Jurors have acquitted people due to a lack of DNA evidence, despite the fact that not all crimes naturally involve the transfer of DNA. Regardless of the weight of other evidence, jurors expect forensic evidence in every trial. Police and CSIs know that, and have dramatically increased the volume of evidence they collect at crime scenes.... which seems like a good thing until you realize that real-life crime labs (unlike the ones on TV) have small staffs, limited budgets, and enormous backlogs of unprocessed evidence.

It is possible that the CSI Effect is not a real thing (scientific studies of the phenomenon are mixed). But if a fictional effect has created a real shift in evidence-gathering behaviour, that creates a real life problem, the ramifications of which are not yet fully known.

I blame Hollywood. But I still watch forensic shows, because they are some of the only shows on TV where scientists get to be stars.

Are you a fan of forensic shows? Which ones are your favourites? Have you given up on shows because they just can't get the science right?

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Want me to talk to your seventh graders about forensic fact and fiction? I'm a member of the Nova Scotia Writers in the Schools Program and the Writers' Union of Canada, both of which offer subsidies to help bring writers into the classroom. Contact me for details.

You can also pre-order my new forensic book for grades 3-6, Discover Forensic Science.

Raptors in residence: The fun way to learn about hawks, falcons, and other birds of prey

By Marie Powell

As the author of a book called Hawk, I was naturally interested when the Canadian Raptor Conservancy came to Regina earlier this month.  This group has a focus on conservation and education, bringing live bird shows across Canada.

Many of the species are endangered, so the shows offer a unique opportunity for the public to see these birds up close. In Regina, we saw a great horned owl, several species of falcons and hawks, and even a bald eagle.

During the shows, the handlers use posts for the birds set in strategic areas around the room. They carry the birds to the posts, then walk away. At a signal, the birds swoop through the crowd -- often right overhead -- to fly back to the handlers for their reward. The show set up in Evraz Place in Regina to get enough room for these dramatic flights that quickly won over the crowds on a cold January weekend.

That also let them set up displays of falconry equipment, wall-sized photos, and display cabinets of bird feather, bones, anatomy, and a full-sized mural of bird wingspans for children to compare against their own outstretched arms.

The combination of macabre and informative displays made for exciting set-ups to catch the attention of the crowd between shows.

Between the shows and the displays, people who attended had many opportunities to learn a few facts about the birds and their handlers. For example, the peregrine is the fastest bird in the animal kingdom. In a dive (or stoop), peregrines tuck in their wings in a teardrop shape to reach speeds of over 300 k/h (200 mph). With breeding programs for more than 15 species, the Ontario facility houses some 200 birds bred in captivity, and releases some of these birds back into the wild.

In Regina, the group teamed up with Little Ray's Reptile Zoo and the Backyard Conservation Fund of Canada, alternating the raptor shows with live snakes and reptile demonstrations. Reptiles of all kinds were also housed in display cases throughout the show area.

Large poster boards and displays also gave the conversation message, and the handlers were ready to talk about their message during and between shows. Many raptor species face habitat loss from such human activities as urban sprawl and pesticides, so these shows offer a unique opportunity for the public to interact and learn a little about ecology and conservation at the same time.

Here are some more websites to check for information about raptors:

Canadian Raptor Conservancy
http://www.canadianraptorconservancy.com

Audubon: Identify Raptors in Flight:
https://www.audubon.org/news/identify-raptors-flight

Watch a video of a peregrine falcon in flight:
https://www.youtube.com/watch?v=Me3Y64VUqqQ

Amazing Planet: Five fastest birds
https://www.youtube.com/watch?v=MMsLVxcKh24

Watch for the Canadian Raptor Conservancy shows as they move across Canada. Have you seen a show yet? Leave a comment and let's discuss it.


Marie Powell is the author of the young adult fantasy Hawk (Five Rivers),  as well as 30 other books for children and youth on a variety of topics. More information about her and her books can be found on her website at www.mepowell.com.

A Tribute to Scavengers and Decomposers

by Jan Thornhill

I visited a school a few days ago to talk about my books and, as usual, passed around the contents of my “museum-in-a-bag,” a collection of, among other things, skulls, dinosaur bones, desiccated insects, snake skins, feathers, and a mummified bat and two hummingbirds. The children are always very careful with my treasures, but that day my white-tailed deer skull finally snapped in half. I wasn’t exactly surprised, since this particular skull has been handled by at least 5,000 kids over the past few years. Besides, I can always glue it back together again. I’d like to save it, though, because, like many of the things in my bag, the deer skull has a story.

White-tailed deer skeleton (Jan Thornhill)

I found it, along with most of the rest of the deer’s skeleton behind a fence on my road. It’s not hard to imagine how the animal died: I’m sure someone struck it by accident with their car. Though mortally injured, it must have managed to make two great bounds, one to get off the road and the other to get over the fence. The person who hit it must have been relieved to see it disappear into the brush as he or she drove away. But then, alone, the deer collapsed and died.

A year earlier, I had looked for puffballs in exactly the same spot in late autumn. There were no deer remains then, so the longest it could have been hidden there was twelve months. Amazingly, other than a few wisps of hair and a couple of snippets of dried skin, the skeleton was completely clean – clean enough that I had no qualms about bringing it home.

So who do I have to thank for cleaning those bones for me? Scavengers and decomposers, that’s who – my favorite characters in the food chain.

I was quite sure a coyote must have visited the corpse of the deer shortly after it died since the bones of two of its legs were missing. The coyote is the only animal in my neighborhood that is strong enough to drag away such large parts. Though they’re predators, and often hunt for food, coyotes are also such frequent scavengers that they’ve developed a special receptor in their brains that makes them immediately throw up anything that is dangerously rotten. So a coyote wouldn’t have had to feed on the carcass immediately, especially if the deer had died in the cold of winter.

Coyote feeding on elk carcass (Courtesy Bryan Harry, U.S. Fish & Wildlife Service)

Turkey vulture

Other scavenging mammals, such as foxes and skunks, might also have visited the corpse, as well as birds, such as crows and vultures. Our local turkey vulture is one of the few large animals that is a dedicated scavenger, which means that its only food is carrion, or already dead or decaying flesh. They’re perfect for this job: they have an extremely well-developed sense of smell that allows them to home in on food that's miles away; their bald heads reduce the amount of rotting matter that might stick to them; strong acids in their digestive tracts destroy harmful bacteria; and their urine is also very acidic – and here’s the best part – so they pee down their legs to let the acid destroy nasty bacteria clinging to them. 

As well as being fed upon by these larger animals, in the warmer months corpses attract an amazing number of insects. A variety of flies are lured by the smell of death and lay their eggs. Their larvae, or maggots, are voracious carrion feeders. Flesh-eating beetle larvae continue the job and, later, other beetles with specialized mouth parts show up to feast on tough skin and ligaments, followed by moths that eat fur and hair. These insects all arrive at such specific stages of decomposition that forensic entomologists, scientists who study the insects that are found on or near dead things, can use their knowledge of this progression to determine the time of death when the remains of a human are found.

Close-up of a blowfly maggot (Eye of Science)

Throughout this whole process bacteria are active, gobbling up the corpse from within. These bacteria produce gases as a waste product, and it’s these gases that are responsible for the putrid odors that waft off rotting animals. Humans are naturally revolted by these smells, which is a good thing. If we weren’t disgusted by the smell of decomposition, we might be tempted to eat food that has gone bad and get sick from the bacteria growing on it. Interestingly, almost everyone in the world says the same thing when confronted by these smells, some version of “Yuck!” or “Ick!” This verbal gagging is so natural and so universal that some people think it might be the way that human language began.

My tip to anyone who finds an animal skull (or other bones) and wants to bring it home, is to use your eyes and nose. If it looks gross and smells disgusting, leave it where it is. Mark the location and return in a few months. More often than not, scavengers and decomposers will have completely cleaned it up for you.

You can find out lots more about death and decomposition in my book: I Found a Dead Bird: The Kids’ Guide to the Cycle of Life & Death (Maple Tree Press)

Here’s a fun, time-lapse video showing a watermelon decomposing over 35 days: http://thekidshouldseethis.com/post/12926682492