Travel Reference
In-Depth Information
Our understanding of the living world can always be deepened by a Dar-
winian perspective. As we look at the world through evolutionary eyes, we
come away with a renewed sense of wonder about life's astounding present-
day diversity, along with a new appreciation of that diversity's fourth dimen-
sion—its long evolutionary history. When we think about our planet from
an evolutionary point of view it also becomes achingly clear that when we
lose a species or an ecosystem, we lose many millions of years of history.
And each such loss reduces the ecological diversity on which the survival of
our species and the entire biosphere depend.
New discoveries by evolutionary biologists have a direct bearing on this
loss. In recent decades it has been shown that all populations in nature are
fi lled with genetic variability, a fi nding that provides yet another dimension
to the Darwinian way of looking at the world. This genetic variation, like a
full tank of gas in a car, provides the motive power for future evolutionary
change. At the same time as we try to preserve species and entire ecosystems
from extinction we must also preserve the genetic variation within species.
If, through inbreeding, the few survivors of a species have lost that full tank
of evolutionary gas, then even if we manage to nurse that species back to
apparent health it may remain on the critical list for centuries.
The preservation of genetic variation has a direct bearing on our own
survival. Many of the crop species and domesticated animals on which we
depend have lost critical variability. Through our own ignorance and mis-
management we have driven many of their wild relatives to extinction, los-
ing reservoirs of critical variation in the process.
In this topic we will embark on a series of adventures that illustrate this
evolutionary way of looking at the world. To help communicate the impact
that these experiences have had on me I have provided photographs that I
took in the heat of the moment.
We will begin with a look at the teeming underwater life of Indonesia's
Lembeh Strait, and then explore how this diversity arose from distant simple
