[title] Opposites: Big and Small [narrator] The natural world is filled with many wonders, big and small.
Diversity across the tree of life is evident among the millions of specimens in the national natural-history collections,
housed at the Canadian Museum of Nature's research campus in Gatineau, Quebec.
Let's open up the collection cabinets and discover some of these amazing specimens.
[Andrew Smith, Ph.D.] I'd like to show you some examples of some very large and some very small beetles.
These are some of the largest and smallest insects known.
Starting at the larger end, we have Megasoma actaeon, Dynastes hercules, and Titanus giganteus.
At the smaller end, we have the family Ptiliidae. These are feather-winged beetles
and this is a worldwide group. And all of these very large and very small beetles can fly.
[Jordan Mallon, Ph.D.]So I thought I'd talk a little bit today about large- and small-brained dinosaurs.
When I think about a large-brained dinosaur, I think of this animal right here, called Troodon.
We have a brain case here of Troodon, from the top of a skull.
In 1969, a palaeontologist here at the museum named Dale Russell described this brain case, and he noted
that impressed into the skull roof is the impression of the brain.
And this suggested to him, at the time, that Troodon and these other small raptor-type dinosaurs
were quite intelligent. And you see that idea echoed today in movies like Jurassic Park,
where you see these intelligent, raptor-like dinosaurs opening doors to get into the kitchen.
By contrast, if I turn around here, we have a brain case of Triceratops.
And if you look at its brain, you'll see it's quite a bit bigger, but relative for its size, it's actually really, really small.
And if you look carefully, you'll see that the impression of the brain within the brain case here is not as well developed,
which suggests that the brain is actually quite a bit smaller than what you see here.
[Danielle Fraser, Ph.D] Mammals during the last ice age were considerably bigger than today. And one example is the giant beaver, here beside me.
The Giant Beaver was considerably larger than the modern beaver, weighing in at a whopping 100 kg, or 200 pounds.
Here you can see two different jaws that I'm holding. The one on my right belongs to the modern beaver, Castor canadensis.
And the one on my left belongs to the giant beaver from the Yukon, Castoroides.
And you can see, when we put them next to each other, the drastic difference in size.
[text] Unlike its modern relative, Castoroides did not cut down trees to build dams.]
Have you ever wondered why there are big animals and small animals?
[Dominique Fauteux, Ph.D.] Well in ecology, there's a phenomenon called fitness, which is the capacity of an animal to pass on its genes over several generations.
Or in other words, an adult having babies, and those babies having babies too.
So, for small animals, the strategy will be much different than the big animals, especially in terms of reproduction.
So, for small animals, it will often be animals having many litters, many babies, also, per litter.
And for big animals, it's going to be only one litter per year, with a few individuals.
But for the bigger animals, usually the survival will be the key,
but for small mammals it will really be their reproduction. And in the end, it's that interplay between survival and reproduction
that will bring the fitness of both species at about the same level.
And that will give them similar success in evolution and allow them to persist through time.
[narrator] Ranging from the massive to the minuscule, the museum's collections contain over 14.6 million specimens.
Each one tells an important part of the story of life on Earth.
[text] To learn more about the National Natural History collection, visit nature.ca