This video was sponsored by KiwiCo. Hi, this is Kate from MinuteEarth.
And today, we’re doing something a little different. All of us on the MinuteEarth team
have plenty of strong opinions - including how we feel about our own videos! So here, three of
our writer-directors will each share one of their favorite MinuteEarth videos and explain why it’s
at the top of their list - maybe it’s the awesome analogy, maybe it’s the storytelling style,
maybe it’s the particularly prodigious puns. I’ll start: I LOVE “Why Poor Places are More
Diverse”, the brainchild of our great writer Peter. It is totally counter-intuitive that
greater numbers of species grow where soils are...well...dirt poor. But this video so
cleverly explains why poverty drives diversity not only in the natural world,
but elsewhere on our planet too. Take a look. A soccer-field sized patch of forest in frigid
Alaska has about 40 different species of plants, compared with about 70 in temperate England
and 300 in the Amazonian rainforest. These biodiversity differences hold true for entire
countries, too: England has 1500 plant species, while tropical Guyana has six times that many.
The super-diversity of tropical rainforests is only equalled in one other type of ecosystem
on Earth: scrubby fire-prone shrublands that grow in western Australia and southern Africa.
These shrublands may not look as majestic as tropical rainforests, but in a given area, they’re
home to similarly stupendous numbers of species. Which doesn’t necessarily mean that the
rainforests and shrublands are easy places for plants to live. In fact,
both ecosystems owe their enormous diversity, in part, to the fact that their soils have
critically low supplies of nitrogen and especially phosphorus, nutrients plants need in order to
grow. The plant world’s leading biodiversity hotspots are, quite literally, dirt poor.
Logically, it seems like richer soils should support more species. But in nature,
as in human society, ‘plenty of resources’ doesn’t necessarily translate into ‘everyone gets plenty’.
In meadows, forests, and wetlands around the world, we consistently find more or
bigger plants but fewer species where soil nutrients are highest. The fastest-spreading
species soak up most of the extra nutrients, which lets them keep growing super fast,
which lets their roots suck up so much water, and their leaves snatch up so much sunlight, that
other, slower species actually get LESS of those resources than otherwise. So in rich soils, slower
species die out while the fast-growers win big. On the other hand, poor soils don’t provide enough
nutrient capital for fast-growing plants to build their massive infrastructures and take all the
resources. So poor soils inhibit the greedy and allow everyone else to scrabble by. We see this
pattern in human society also - there’s a far greater number of businesses – mostly small –
in poor countries, while fewer bigger companies dominate in rich countries.
But crummy soil isn’t the only thing that helps super high diversity blossom; for example,
beaches, mountaintops, and other places frequently ravaged by harsh weather or catastrophic events
have poor soils AND few plant species. The other major prerequisite for hyperdiversity is time.
On most of the planet, glaciers regularly bulldoze away ecosystems and grind up mineral-rich rock,
creating new soil perfect for growth but not diversity. However, our high-diversity
rainforests and shrublands have spent millions of years beyond the reach of the ice sheets,
leaving their residents plenty of undisturbed time to evolve a wide variety of ingenious strategies
for surviving nutrient poverty – strategies that have allowed for the development of tall,
diverse, rainforests in wet poor soils and scrubby, diverse, shrublands in dry poor soils.
The human landscape also seems to follow a similar pattern, with the highest cultural and
linguistic diversity as well as the greatest number of businesses in climatically stable
places where humans have been the longest and where economic resources are scarce.
So in some ways, the poorest places on earth are actually (also) the richest.
That ending blows my mind every time. It’s incredible how similar the processes that shape
the world around us are to those that shape who we are. But that’s enough philosophizing
from me - here’s David with his pick. Thanks Kate! My favorite MinuteEarth videos are
the ones that totally make me rethink the way I think about everyday stuff. And every time I go to
the store, I think about this awesome video - also written by Peter - about the relationship between
beer and biodiversity. Now, whenever I'm in the beer aisle and I look at a cute local microbrew,
I think about it as a cute little plant trying to survive in a mean jungle filled with
big breweries that are trying to get it. Go watch the video, enjoy, I'll see you at the end.
In the local shop, next to major beer brands, you might find microbrews with crazy names like
Wild Skunk Ale, Fiddlehead Fuel, or Mudsucker Stout. While the big-brands run TV ads starring
sexy skiers or tough guys with trucks, their small competitors have to scrabble for attention from
the store shelf. That’s because, much like a small shrub or fern beneath the tall trees in a forest,
microbreweries live in the shadows of their larger corporate competitors.
And, surprisingly, many species and businesses that eke out a living in the shadows of giants
employ similar strategies to succeed in their respective dog-eat-dog worlds
of intense competition for limited resources. The winners of this competition in the forest
or beer business, as defined by sheer volume, are those that capture the most resources - sunlight
in one case and consumers’ dollars in the other. The mechanics differ - big trees capture sunlight
by being tall, while large brewers earn billions of dollars of profits by having a broad reach,
attracting customers with low prices, large advertising budgets, and mild flavor.
The outcome is the same, though - by capturing the most valuable resources before they reach others,
dominant trees and companies exclude weaker competitors who employ the same
tactics. But there are trade-offs to any strategy, and being the best on average
rarely works in all cases and conditions. That’s how understory ferns and microbreweries
can succeed - by specializing in conditions the “big guys” are not
so good at: the so-called empty niches. In deep shade, a fern can make a healthy, if
modest, living by avoiding direct competition and investing prudently in just enough photosynthetic
machinery,, to make a profit from the faint sunlight reaching the forest floor-- leftover
light not worth the extra effort for the big trees to capture up above. Ferns can even thrive
on a photosynthetic income that’s inadequate for the small offspring of many tall trees,
and thus the humble fern coexists with the tall timber above by competing on its own terms.
Similarly, microbrews, which invest in being odd, trendy, and strongly flavored, can persevere
by attracting aficionados not swayed by the marketing and lower prices of larger breweries.
Sure, fewer people fall into this category, just as fewer beams of sunlight fall through the
canopy onto the forest floor, but where there are resources, there’s potential to survive.
And survival is the goal of both ferns and firms, so it’s not really that surprising
that both nature and the economy, driven by the same kinds of competition, give rise to niches
and diversification, to canopy and understory in the forest, and in the supermarket aisle!
Have you guys ever noticed that canopy sounds like can o’ pee? At any rate,
I’m off to try to go find some Fiddlehead fuel. Julián, you're up next!
Thanks, David! One of my favorite videos is Kate’s “How We Evolved To Browse The Web.”
We humans think we’re all that – and from the perspective of our command of global resources
we certainly are – but as this video points out, some of the things we do that seem uniquely human,
like hunting for memes on the internet, are not so different from how our fellow animals behave.
Kate did an excellent job of looking at human behavior through a zoological lens, check it out.
Hi, this is Kate from MinuteEarth. Let’s find some cat memes! This site looks good - yeah,
there’s some funny kittehs and some great cattos on here! But, well, hmm...
the pickings are definitely getting slimmer. Maybe we should try another site? But that
means we have to FIND another site! And we’re already here… so, should we stay or should we go?
Well, it turns out that online, we forage for information just as, say, a chickadee forages for
fruit; it has to choose which tree to visit and decide how long to nom there before abandoning it
and finding another. Ecologists already have all sorts of models to describe how animals forage.
And it turns out that one of these models, which explains how animals move between patches of food,
also predicts how humans move between websites: both you and the chickadee will forage in one
place until the rate of reward you’re getting there drops below what you think you’re likely to
get elsewhere. This calculation is subconscious, of course - you’ll just notice the tree is getting
bare, and move on. It’s a matter of spending your time and energy in a way that gets you as much
reward as possible...and that’s something foraging animals - and humans - do all the time.
For instance, we’ve found that chipmunks that take longer seed-gathering trips bring back
bigger hauls than those that take short ones. That makes sense: it’s only worth spending lots
of resources if you can score big. And a study of more than 400 robberies in the Netherlands found
that the farther burglars travel to commit their crimes, the more expensive their loot tends to be.
Researchers have even found that the longer we search for a romantic partner, the more
likely that relationship is to last; perhaps a bigger investment leads to a better payoff.
We probably optimize like animals because we are animals, and in fact, we share critical
decision-making circuitry. For instance, monkeys have special neurons that seem to track the rate
of reward the monkey is getting in a patch - when it drops too low, the neurons send an electrical
signal to the monkey, who switches to a new patch. We also have these neurons - and there’s evidence
to suggest that lots of other animals do too; they were likely so critical to making good
food-finding tradeoffs in the distant past that they were passed on over lots of generations.
This kind of shared machinery may help explain why we behave like our non-human kin.
Of course, most of us humans now find ourselves evaluating how fruitful websites are
much more often than how fruitful fruit trees are, and the stakes of wasting your time on
dumb cat memes are far lower than wasting your time searching for sustance. But it’s not just
web surfing...at what point do you move on from a lame TV show, or ditch the long line at the DMV,
or give up on a job - or even a relationship - that you’re not that into? It turns out that the
constraints - and the underlying machinery - that guide us in these everyday scenarios are likely
the same as those that guide animals...which means that deep inside, we’re all a little bird-brained.
I’d like to personally thank your neurons for staying with us, and they chose
wisely – here’s Henry’s with his choice. Awesome Julián. One of my favorites is
“Why is it Hot Underground?” written and narrated by our former team member,
the excellent Emily Elert. What I love about this video is it starts with a simple question,
then takes us on a journey with lots of tantalizing false turns and dead-ends (including
some that people STILL get confused by - silly radioactivity) and then it culminates in a truly
modern explanation of our planet’s thermodynamics (spoiler: it’s not like a baked potato).
Way back in the Middle Ages, miners began to notice that the deeper they dug into the earth,
the toastier it got. Who knows what they made of the heat, but the physicist Lord Kelvin - of
temperature fame, naturally - had a theory: Earth started off hot, and has been cooling down ever
since, like a baked potato pulled from the oven. What’s more, Kelvin was confident this
idea would allow him to calculate the age of our potato – I mean, planet...
Imagine pulling two recently-baked potatoes out of a freezer - one that's been in there for
just one minute, the other for half an hour. The minute-old-one would still feel like a hot potato,
while the half-hour frozen spud would have cooled well below the skin — you’d have to
poke all the way to the center to feel its residual warmth. And so in principle, you
can tell how long ago a potato was cooked just by feeling how warm it is right beneath its surface.
Which is exactly what Kelvin did - except with the earth. And scientific rigor. He took temperature
measurements from the mines, put them into his calculations and, got... 20 million years.
Which is, of course, very, very wrong — somehow, the hot temperatures just under Earth’s skin
made it seem, to Kelvin, that our planet was pretty much fresh out of its cosmic oven,
when we now know that it’s four and a half THOUSAND million years old.
Kelvin’s error is usually attributed to the fact that he didn’t know about radioactivity, which
creates a ton of heat in Earth’s core and helps keep the planet warm. But heat from radioactive
decay moves so slowly through solid rock that taking radioactivity into account only improves
Kelvin's estimate by… pretty much nothing. Kelvin’s real oversight was in thinking of the
Earth like a baked potato — a solid lump through which heat slowly diffuses. Earth’s mantle — the
thick layer between the crust and the core — is mostly solid, but it isn’t rigid. In fact,
the rock closest to the molten outer regions of the core gets so hot that it becomes slightly
more pliable, like warmed candle wax. And like the hot air above a candle, the warm rock rises
in convection currents - over millions of years - spreading heat more evenly throughout the planet.
This stirring carries tremendous amounts of heat from the core to the crust, fueling volcanoes,
maybe helping to drive plate tectonics, and heating mineshafts to temperatures that make Earth
seem like it’s fresh out of the cosmic oven. Even though it’s not.
Alright, thanks Kate, David and Julián for the trip down memory lane. And stay tuned,
our illustrators are going to be doing the same thing, coming up soon. Bye!
Speaking of our favorite stuff, the MinuteEarth team are big fans of KiwiCrates - boxes that come
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David’s two little MinuteEarthlings already have monthly subscriptions,
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