Diversity is something we notice every day.
We say, for example, that these apples
do not differ, that they are all the same.
But, looking around, we can see
there is a lot of diversity.
And it is often what we want.
Hundreds of years of gardening went into
all the forms and colours of orchids.
It would be a mistake to only
notice the different colours.
Each of these plants could be
short or tall,
have narrow or wide leaves,
and short or long roots.
Are there limits to diversity?
Natural diversity is not just about
diverse shapes and sizes.
It is also about being a green plant
or a forest mushroom.
It is about having six legs
or a spine.
It is about being cold-blooded,
or being able to fly.
Life on our planet shows diversity
at every level of organisation,
from the varying lengths of dog tails
to the astonishing diversity
among primates.
As representatives of homo sapiens,
we are also a result of diversity.
This whole explosion of diversity
has been possible thanks to the force
discovered by Charles Darwin
at the end of the 19th century.
Natural selection is responsible
for the entire diversity of life
and draws from it
every step of the way.
How did it result in the ability to fly
and the beautiful smell of roses?
Imagine a unique organism
called stravus ordinarus.
It grows in the ground
and absorbs air.
We've just discovered a new population.
There is no diversity in it at all.
All the specimens are perfectly straight
and of the same height,
so they absorb dust from the air
with the same efficiency.
What will happen when
natural selection starts working?
Imagine natural selection
in the form of an unusual cataclysm.
No specimen is ready for
such a violent change in the environment.
The population is unable to reproduce,
and it dies out.
On a larger scale,
something similar happened
when all the dinosaurs
died out in the Cretaceous.
None of them were ready for such
a sudden change in the environment.
The population couldn't produce offspring
and died out completely.
This is shown by the lack of white tops.
Let's now introduce a bit of
diversity to our population.
This time, some specimens
have survived the cataclysm,
and even managed to reproduce.
Their average height is slightly lower,
but it is what gives them the advantage.
The next stages of the cataclysm will be
even more bearable for the population.
More smaller specimens means
that more specimens will survive.
the distribution of height
will move towards smaller values.
Still, diversity will be preserved,
and specimen will not all be the same.
Diversity is not just a coincidence.
It is a key characteristic that
allows nature to quickly react to changes.
For example, if a mutation occurs
in a population of unscented flowers,
and scented flowers appear,
they will attract more pollinators.
They will reproduce more effectively.
Diversity is so powerful
that it resulted in the smell of flowers.
It also produced us
so we can admire the smell.
