Apr 202017
 

One of the greatest gifts you can give a child is a sense of wonder in the natural world and how everything in nature can be explained by science and critical thinking. And nowhere is there a better example of the power of critical thinking than when it comes to evolution. Even though a full understanding of the mechanisms of evolution requires an understanding of genetics, children can usually grasp the essential components by age seven or eight. These components are variation (individuals in a population of the same species can vary somewhat in their traits), inheritance (traits are inherited from parents and passed on to offspring), natural selection (life forms with traits that help them to survive and reproduce are most likely to pass on these traits to the next generation) and time (major change usually takes thousands of generations or more).

Effective questioning 

Thoughtful questioning not only serves to clarify the components of evolution but also helps elicit a sense of wonder, curiosity and deeper appreciation of nature itself. Start by encouraging children to look in detail at the organism or behavior in question. Ask them to describe what they see and why they think the plant or animal looks or behaves that way. Always use the language of beauty and awe: “Isn’t a woodpecker amazing! Imagine yourself making a living this way!” Ask open-ended questions starting with “Why?” or “What do you think?” Encourage the kids to do the same. If they don’t know the answer, help them come up with a reasonable hypothesis — an educated guess. Model this yourself. Later, follow up with an Internet search. Remember that it’s perfectly fine to say “I don’t know” or “Scientists don’t have an answer yet.”

Pileated Woodpecker – Jeff Keller

Time activities

One of the hardest things for kids and adults alike to grasp is the concept of evolutionary time and numbers like a million or a billion. Counting can be helpful here. Ask a child to count to a 100. This might take 30 seconds if they count quickly. At that rate, counting to a 1,000 takes about 5 minutes, to 100,000 takes a day’s work (10 hours), to a million takes two weeks work, to 100 million takes five years work, and to a billion takes a whole working life. Imagine how long a billion years is!

Toilet Paper Timeline: This is a fun way to help children visualize the massive amount of time that life on Earth has had to evolve. You’ll need a roll of toilet paper of 450 sheets (tear off 50 from a roll of 500), sticky notes and a long hall or open area outdoors. Explain that the Earth is about 4.5 billion years old and that life first emerged about 3.5 billion years ago. You might add that we don’t yet fully understand how life began, but scientists are getting closer and closer to the answer.

Toilet paper roll

If you are going outside, choose a calm day. Unroll the entire roll of toilet paper. Each square of toilet paper represents about ten million years. Write down each stage (see below) on a sticky note. Attach the sticky notes to the squares indicated. Take the kids on a walk along the timeline and discuss as you go. Be enthusiastic and use the language of wonder! Note: BYA = billion years ago; MYA = million years ago 4.5 BYA: Earth is formed, along with the other planets (square 1), 3.7 BYA: Earth’s crust solidifies (square 80), 3.5 BYA: first life appears in oceans (square 100), 3.25 BYA: photosynthesis begins in oceans (square 125), 2.4 BYA: oceans contain significant amounts of oxygen (square 260), 1.9 BYA: first cells with nuclei appear in oceans (square 310),  650 MYA: first multicellular organisms appear (square 385), 500 MYA: first land life (square 400 ), 250 MYA: massive volcanic eruption kills mass extinction of 96 percent of all life (square 425), 245 MYA: Age of Dinosaurs begins (square 426), 200 MYA: the first mammals appear (square 430), 150 MYA: supercontinent breaks up and continents drift apart (square 435),  65 MYA: Asteroid impact ends Age of Dinosaurs and kills 70 percent of all life  (square 444),  3.5 MYA: first early humans appear in Africa (last square, 3.6 cm from the end),  100,000 years ago: first Homo sapiens, our species, appears (last square, 1 mm from end),  10,000 years ago: recorded human history begins (last square, 0.1 mm from end)

More activities

1.  See your DNA: Believe it or not, it’s easy to see your own DNA, the recipe that makes you. Mix a half-quart (500 ml) of drinking water with 1 tbsp (45 g) of salt and stir until salt is dissolved. Transfer 3 tbsp (14 ml) of salt water into a clear glass. Swirl the salt water around in your mouth for 1 minute. Spit the water back into the glass. Cheek cells will be suspended in the salt water. Gently stir the salt water with one drop of clear dish soap. (Note: Soap breaks down the cell membranes, releasing the DNA.) In a separate glass, mix 7 tbsp (105 g) of isopropyl alcohol and 3 drops of food coloring. Tilt the salt-water cup and gently pour the alcohol–food color mixture so that it forms a layer on top (about 1 in. /2 cm thick). 8. Wait 2 ½ minutes. You should see small white clumps and strings forming. That’s your DNA!

2.  Camouflaged Eggs: The eggs of birds that nest on the ground (e.g., killdeer, ruffed grouse) are highly camouflaged, not just in colour but in pattern, too. These birds will also choose ground (e.g., dark sand instead of light sand) that offers the best match to the egg color and pattern. In other words, birds and their eggs have evolved to maximize camouflage. Species that nest in cavities often lay all-white eggs, since camouflage is not a concern. For this activity, you’ll need hard-boiled eggs and different colored markers or tempera paint.

Show the children pictures of real eggs from ground-nesting birds. Discuss the most effective colours and patterns. Visit a natural area where the eggs will be hidden. Ask the children to think about how to best camouflage their eggs. Each child then takes two to three eggs and uses paint or markers to colour and mark them. Have them hide their eggs in a designated area. Hide a few unpainted white eggs as well for comparison. Excluding their own eggs, how many can they then find in two minutes? Which were the best camouflaged?

Cedar Waxwing nest with eggs – Wikimedia

3. Adaptations Scavenger Hunt: For many plants and animals, spring is a time of mating and reproduction. Over millions of years, special adaptations have evolved to make this process possible. These include adaptations for attracting a mate, defending a breeding site and, in the case of plants, evolving ways to have their genes spread by the wind or by animal pollinator.

Make up a list of common adaptations to look for and give each child a copy. Briefly discuss the purpose of each adaptation. Here are a some ideas: 1. brightly colored flowers (attract pollinators), 2. flowers with a strong scent (attract pollinators), 3. flowers with lines or spots on petals (guide pollinator to nectar), 4. a “catkin” flower (e.g., poplar) hanging like a caterpillar from the twig (easily jostled by wind, thereby spreading the pollen), 5. a bird chasing another away (defending nest or territory) 6. brightly colored male birds like a mallard or cardinal (attract a mate), 7. a dull-coloured female bird (camouflage on nest), 8. male birds singing (attract a mate, defend territory)

Visit an area where the kids are likely to find the flowers and birds in the list. They may want to use a camera to take pictures of the adaptations. Encourage them to add other probable adaptations that they see. Share and discuss.

4. Meet the Beast Within You:  In this activity, kids will learn about our remnant body parts and behaviors that link us to our distant past. Our ancestors needed these “vestiges” in order to survive. Our bodies still carry dozens of reminders of how we used to be millions years ago. However, humans are very different now. We no longer walk on all fours and don’t wear a thick coat of fur. Over time, we have evolved into the bare-skinned and big-brained creatures we are today.

Ask the kids to try the following: 1. Feel their coccyx at the bottom of their backbone. It is the remnant of a lost tail. 2. Using a mirror, look at their canine teeth. They were very useful to early humans for tearing tough flesh. Compare to those of a dog (show picture). 3. Using a mirror, have them make a big, toothy smile. Smiles were a way for early humans to scare away an enemy. Their meaning has changed! 4. Ask if anyone can wiggle their ears? Early humans could do this to help in hearing, just like dogs today. Because of a genetic mutation, only some people can do it now. 5. Have them put their arm in cold water until goose bumps appear. These bumps were the body’s way to erect the thick fur we once had. This made us look larger and more ferocious. Show a picture of a dog with its back hair raised. Ask why our hairy coats may have disappeared?

Coccyx (in red) (Photo by DBCLS)

Earth Day should be about more than picking up litter. Make it a celebration of our planet’s amazing biodiversity and the process behind life’s myriad forms – evolution.

 

 

 

 

 

Apr 132017
 

Kids make great amateur scientists. They love to ask “why” questions. “Why is the monarch butterfly so colourful? Why does it start life as a caterpillar? Why does it migrate? Thanks to Charles Darwin, we now understand that questions such as these are entitled to an evidence-based answer – and it is the theory of evolution that provides the answer. To quote evolutionary biologist Theodosius Dobzhansky: “Nothing in biology makes sense except in the light of evolution.” Rather than taking away from the wonder of nature, understanding evolution only adds to it. There are so many mysteries in nature that we’ve not yet solved.

Children merit a truthful and passionate introduction to the natural world around them, especially if we are to harness their innate curiosity. Once children get a sense of how evolution works – and eventually link it to themselves – their eyes light up with wonder. I remember one little girl in grade 4 saying, “You mean we’re animals!” Without a basic understanding of evolution, nature study – and much of biology – risks becoming the memorization of species names and facts.

Students watching Monarch emerge from chrysalis (Photo: Drew Monkman)

Unfortunately, there’s a perception among many parents and teachers that evolution is hard to explain, or that they’ll get something wrong. It’s really not that difficult at all. Conversations about evolution should be done in context. Allow the children to think the process through themselves. A discussion might go something like this. “Look at that animal over there. What is it? (a squirrel). Is a squirrel a bird, an insect or a mammal? (mammal). How do you know? (It has hair). Okay, well if we lived at the North Pole and we saw a squirrel, do you think it would have more or less hair? (more) Why? (to help it stay warm). So, if the weather here was to get colder and colder every year, what do you think would happen with the squirrels? (develop more hair). Well, you’re right, because there’s always a chance that when baby squirrels are born, some may have more hair than others. This will help these lucky ones to survive, find a mate and have babies. They don’t “try” to have more hair; it just happens by chance. Eventually, all of the squirrels may end up with more hair, since they might be the only ones to survive the colder weather.”

In a nutshell, evolution can be explained to children like this: 1. All creatures struggle to survive and have babies, but many fail. 2. Creatures born with a helpful trait (e.g., a longer bill) are more likely to survive and have babies. 3. Parents pass on the useful trait(s) to their young. 4. Over time, these new traits can lead to a new species – one that can only have babies with its own kind.

Human origins

Eventually, the question of human origin will come up. You might say something like this: “In Africa, there were once primates (e.g., monkeys, lemurs and apes) that were similar to modern day chimpanzees. They became separated into two groups. One continued to live in forests, spent a lot of time in trees and usually walked and climbed on all fours. The other group moved into more open fields and had to spend more time on the ground. Over time, the second group started acting differently like walking upright, which is better for seeing long distances above the grass. Over about seven million years (it takes about three days to count to a million, non-stop) the differences between the groups increased, until the second group became more or less like we are today, and the first group became chimpanzees. That’s what evolution is: if living things find themselves in a new environment- let’s say living in fields instead of forests – they change over time in order to survive. As for humans, we evolved to have big, smart brains in order to “think” our way to meeting our needs. For example, we began to build tools and to develop language. Scientists have found fossils of many of our human ancestors.” A great video to watch with children eight or older can be found by Googling “Khan academy + human evolution overview”.

Model of Homo erectus, an early species of human – Wikimedia

If kids ask about explanations that don’t align with evolution, tell them not to accept what others say – even Mom and Dad – but to focus on evidence. This includes fossils, the amazing similarities in the fetuses and bodies of humans and all other vertebrates and the similarities in the genes, which you can explain as the recipes for making plants and animals. Tell them that when scientists look at chimpanzee genes, they are practically identical to those of human genes. We even share more than half our genes with bananas! Kids are great critical thinkers if you give them a chance.

Activities

1. Small changes: This activity shows how small changes over time make a big difference. Draw a simple bug on the first page of a stack of paper. Then pass the paper on to another person and have them draw the bug as exactly as they can. They should move the original to the bottom of the stack. Have them pass their copy onto the next person who will try to reproduce the bug. Don’t forget to hide the previous version under the stack. Do this at least ten times. Compare the original to the “evolved” bug. Was there much of a difference? All it takes is a small change (mutation) in each generation to create huge change over time. Think of how birds evolved from dinosaurs!

2. What’s bugging you? Here’s an interactive story about bugs, which can help young children understand the concept of evolution. “Let’s say I release 100 bugs onto a green lawn. Fifty are green and 50 are brown. Now, which bugs do you think will best be able to hide from enemies like bug-eating birds? (Most kids will say green ones.) So, if I go back in a few years, would I find more green or more brown bugs? (green again). And, what color will the babies of the green bugs be? (green). That’s right. Just as your mom or dad passed on a certain trait like your blue eyes, the parent green bugs will pass on the green color to their babies. (Now comes the tricky part.) Let’s say some green bugs that usually live on green lawns get blown in a storm to an island where there is mostly brown sand. Life will be hard. However, once in a rare while, a pair of these green bugs might produce a brown baby. This is because little mistakes sometimes happen in how an animal’s body makes a baby. Do you think those rare brown babies would escape enemies more easily? (yes). And, if the rare brown bugs live a little longer because they can hide better, do you think they may have more babies than the green bugs? (Most kids will agree.) What color would most of the babies be? (brown.)

As the years go by, brown bugs will become more and more common. Color isn’t the only thing that might change, however. Because a sandy habitat offers fewer places to hide, the babies that are born with other good traits for hiding — once again because of a mistake in how the parents’ body makes a baby — would end up surviving more easily. Such a trait might be bigger, stronger front legs that are good for digging hiding spots in the sand. Now, let’s say that hundreds of years later, there is another huge storm. Some of the brown bugs get blown off the island and end up on the grassy lawns where their ancestors came from. Would they have trouble surviving? (Kids should say, yes.) Well, that’s not the only problem they would have. Other than eating, what else do all animals do? (Prompt someone to say, “have babies.”) Well, imagine a male brown sand bug meets a female green lawn bug (or vice versa). She might just chase him away or completely ignore him. She won’t want to make babies with him because, being brown and having huge front legs, he looks so different. At this point, we can say that the green lawn bugs and the brown sand bugs have evolved into two different species. Just like horses and zebras!)

Kids are fascinated by living things and why they look and behave as they do (Photo: Drew Monkman)

3. Paper circles game: This is a hands-on version of part of the story above. It shows how nature “decides” (natural selection) who survives and has babies. Using a whole punch, make 50 sand-brown and 50 grass-green paper circles. You might want to use paint sample cards. Sprinkle 20 of each colour on a green lawn. Give the children maybe 30 seconds to remove as many of the little circles as they can (but only one at a time). Then, count the number of circles of each colour that were picked up. For every circle that remains on the grass (20 minus number picked up), add 3 or so of the same colour. This represents reproduction. Repeat the activity for a couple of more “generations”. The children will see how the “population” on the lawn shifts towards the colours that are hardest to see. You can then try the same activity on sand.

Next week, I’ll provide more activities and thoughts on teaching evolution. What better way to celebrate Earth Day than helping kids understand the reason for our Earth’s huge diversity of life!

 

Jun 232016
 

With summer upon us, finding things for kids to do can be a challenge. This week, I’d like to propose a few activities from the new “Big Book of Nature Activities”, which I co-wrote with Jacob Rodenburg of Camp Kawartha. We’re confident that many of the activities will be fun for adults, as well! For more information on the book, go to www.drewmonkman.com

The Big Book of Nature Activities

The Big Book of Nature Activities

Scent Trail

You’ll learn:  How animals follow scent trails

You’ll need:  Lemon, almond, mint, maple or orange extract, blindfolds

Background: Unfortunately, our human nose isn’t sensitive enough to follow natural scent trails. However, many other mammals can. Canids (or members of the dog family) have an incredible sense of smell – many thousands of times better than humans. We might say, “hmmm mac and cheese.” Canids, on the other hand, might say, “Hmmm noodles and cheese and butter and salt and milk and bread crumbs and metal pot and Aunt Marge must have just made this!”

Procedure: In this game, you’ll be given a “helping nose” so that you can follow a scent trail to a reward at the end. Work in partners. One person is blindfolded while the other lays down a scent trail with extract. You only need a drop or two every foot or so for about 30 feet (10 m). Try to lay down a curving trail to make it more challenging. At the end of the scent trail, place a wrapped candy. Guide the blindfolded partner to the beginning of your trail and let them use their nose to find the reward at the end.

Nature Table

A simple, on-going activity is to set up a nature table in your home or cottage. You may wish to label some of the items you display. See if you can find some of the following: leaves of different sizes, shapes, edges, textures, and shades of green (preserved between 2 sheets of clear Mactac plastic); a bracket fungus from a tree trunk; egg fragments from turtle nests that have been dug up by a predator; different types of cones, seeds, berries; a vase of roadside wildflowers;  dragonfly exuviae (cast skin); dead insects like dragonflies or butterflies that you come across;  “scent bouquet” of wild bergamot, milkweed flowers, etc. You can also set up a glass bottle terrarium for temporary “guests” like a toad or salamander.

Pirate Eye

While sitting quietly outdoors, shut one eye and cover it with your hand for about three minutes. Observe the scene through your one open eye. Notice anything? You’ve lost depth perception! After three minutes, switch between your eyes, opening one, then the other. Do this repeatedly. The shades of colours will have completely changed between your eyes. That is because one pupil (the black spot in the middle of your eyes) dilated —  got  bigger —  when you closed it. When you open your eyes again, the world looks brighter through this eye. The other eye, with a smaller pupil, creates darker shades. So which color is real? Do you think all humans see exactly in the same shades? As visual creatures, we humans can distinguish over two million shades of colour.

Pirate eye!

Pirate eye!

Fish Prints

You’ll learn: The patterns and scale structures of different kinds of fish.

Gyotaku fish print - Jacob Rodenburg

Gyotaku fish print – Jacob Rodenburg

You’ll need: A whole fish, a newspaper, acrylic paint, paintbrushes or rollers, paper towels, paper (e.g., tissue paper, construction paper, rice paper, paper plates), fabric (e.g., T-shirt). • Background: Gyotaku, or fish printing using rice paper and ink, originated more than 100 years ago in Japan as a way for anglers to record the size of their catch.

Procedure: Cover the work area with newspaper. Wash off any mucus on the fish and pat dry with paper towels. Place the fish on the newspaper. Slather paint all over the exposed side of the fish using rollers or brushes. Make sure you cover one entire side of the fish. Place a sheet of paper or fabric (e.g., T-shirt) over the fish and press it down firmly, being careful not to move it. Smooth down. Carefully remove the paper or fabric and allow to dry. You can use the fish again for another print. Just carefully wash off all of the paint under a tap.

Natural Perfume

Collect leaves, flowers and buds that are strongly scented (e.g., milkweed flowers, lavender flowers, mint leaves, wintergreen leaves, balsam poplar buds) Chop into small pieces until you have enough to fill a measuring cup. Empty the pieces into a bowl and add a cup of water. Let the mixture sit overnight. Strain the water through a coffee filter and into a clean spray bottle. Spritz over yourself and your friends and enjoy the sweet scent!

Firefly Fun

You’ll learn: How to attract fireflies and make a natural night “light”

You’ll need: Flashlight, glass jar, ice cream tub with lid.

Background: The firefly is a beetle with a special organ in its abdomen capable of mixing oxygen, a pigment called luciferin and the enzyme luciferase. When the insect flies upward, these chemicals mingle and create a flash. As the insect descends, the flash turns off. When a female of the same species sees the flash, she responds with her own light signal. Eventually the male and female fireflies find each other and mate.

What to do: On a summer evening, just as dusk fades into night, visit a meadow where there are fireflies. If you have a flashlight or a wristwatch that glows in the dark, try reproducing the pattern of flashes. Different species of fireflies flash at different rates. Like Morse code, each pulse of light communicates a special message to the opposite sex. Can you attract a firefly by imitating the sequence? You might also wish to make a “night light” for your bedroom. Catch several fireflies in a plastic ice cream tub and transfer them to a glass jar with a lid. Add a few leaves and a drop or two of water. Lie in bed and fall asleep to their lovely star-like flashes. Let them go in the morning.

Plant Weaving

You’ll learn: To create inspiring art by using the vibrant colours of summer.

You’ll need: A forked branch, string or wool, flowers, leaves, grasses, small evergreen boughs.

What to do: Find a sturdy forked stick about as wide as your thumb width and 20–28 in. (50–70 cm) long. Wrap string or wool between the forks approximately  every inch (2 cm). Weave the plant material through the crisscrossing string. You’ll be amazed at the color, texture and form of your creation.

Try this: Collect natural objects (e.g., leaves of various shapes, sizes and  colors; twigs; seeds; acorn caps; evergreen needles; berries; shells) and use them as building blocks to make caterpillars, leaf bugs, flowers, spiders and more. Use your imagination!plant-weaving-jacob-rodenburg

Pond Study

You’ll learn: Some of the intriguing invertebrates that live in ponds.

You’ll need: Pail (preferably with a lid), small aquarium or large glass bottle, small plastic viewing jars, fine-meshed net, shoes you can get wet, hand lens, guide to aquatic invertebrates (go to: http://www.lakesuperiorstreams.org/understanding/benthos_ID.html)

Background: Some of the common invertebrates found in ponds, swamps or streams include mayfly larvae, caddisfly larvae (usually in cases of plant material), damselfly nymphs, dragonfly nymphs, giant water bugs, water striders, water boatmen, backswimmers, leeches and crayfish. Tadpoles, frogs and aquatic salamanders may live here, too. All are easy to catch. What to do: Take your pail, plastic containers and net to a nearby pond, swamp or shallow stream. Either from the edge or by wading out into the water (no more than knee-deep), dip your net down into the dense aquatic vegetation where many creatures hang out. When you catch something like a “wiggling bug,” put it in your pail. Add a little aquatic vegetation to the pail, too. Continue until you have a variety of different creatures. Try different parts of the pond, including the muddy bottom. Don’t pour mud into the pail, however. If you are catching creatures in a stream, many will be attached to the underside of rocks. Gently push them off the rock and into the pail. Don’t be afraid to hold the creatures briefly in your hand. When you have caught a nice variety of different invertebrates, transfer a few to viewing jars for close-up looks and identification. You can then either let them go or take some home to keep for a while in an aquarium or a large glass bottle. Pour the water and creatures into the aquarium and set it on a white sheet away from direct sunlight. If you haven’t done so already, take some time to view and identify each of the different creatures with a hand lens by placing them briefly in a small plastic bottle. Change about one-third of the water every couple of days with fresh swamp or stream water. Have a look every day at what’s going on in the bottle. Have new creatures hatched out of eggs? Have some creatures fallen prey to predators? Be sure to sketch the various species in your nature journal or even photograph them. Include the name. Return the invertebrates to where you caught them after a week or so.