To view the multimedia features on this page, you will need to download the latest version of Flash Player and/or enable JavaScript.

Video Closed Captions

Ignacio Rodriguez-Iturbe:
I am a hydrologist, which basically means that I deal with the movement
of water in landscapes.

Ignacio Rodriguez-Iturbe:
The dynamics of water have a commanding effect on the biodiversity
of fish in river networks.

Ignacio Rodriguez-Iturbe:
River networks are fractals. And fractals are this type of mathematical
construct in which the parts and the whole cannot be distinguished

Ignacio Rodriguez-Iturbe:
from one another. River networks are fractals. Lightning is fractal.
Trees are fractals. Clouds are fractals.

Ignacio Rodriguez-Iturbe:
To the untrained eye they may look very different but there is an
enormous amount of unity in this infinite diversity.

Ignacio Rodriguez-Iturbe:
In a river basin the channel network fragments the space. And its character
as a fractal implies, among other things,

Ignacio Rodriguez-Iturbe:
that the laws that govern the structure of that network are the same
regardless of whether the river basin is small or large

Ignacio Rodriguez-Iturbe:
or is in Venezuela or is in the United States or is in Africa. It is very
different than in a savanna.

Ignacio Rodriguez-Iturbe:
In a savanna -- seeds, animals, people move through a space that is
non-fragmented.

Ignacio Rodriguez-Iturbe:
What we have done, really, is a mathematical model implemented in
a computer.

Ignacio Rodriguez-Iturbe:
We merged different sets of existing data from the Mississippi-Missouri
river basin. It is a fantastically simple model.

Ignacio Rodriguez-Iturbe:
But it predicts wonderfully well all of the biodiversity characteristics that
we are interested in studying.

Ignacio Rodriguez-Iturbe:
From the practical side, it provides us a link to the changes in biodiversity
one can expect from external things like climate change.

Ignacio Rodriguez-Iturbe:
Another aspect is the impact that manmade structures like dams will
have in biodiversity.

Ignacio Rodriguez-Iturbe:
From the science point of view, river basins are crucial depositories of
biodiversity, of energy resources, and human populations.

Ignacio Rodriguez-Iturbe:
We need to understand how the different dynamics that act on them
influence each other.