Darwin and the Long View

Axolotl (Ambystoma mexicanum) Source: National Geographic

Axolotl (Ambystoma mexicanum)
Source: National Geographic

I wonder what Charles Darwin would have had to say about the Mexican axolotl (Ambystoma mexicanum), a feather-gilled salamander sometimes jokingly referred to as the Darwin fish.

The axolotl once swam in abundant numbers in its only native habitat, the network of mountain lakes upon which Mexico City was eventually built. It was a food staple, it was considered useful as a medicinal for respiratory ailments, and Aztec legend held it to be a transformed god who had escaped the politics of fellow gods by transforming into a salamander and hiding among the reeds.

The axolotl is all but extinct in its native lakes, a victim of the usual suspects: pollution, water drainage, invasive species, and overfishing.

Outside its native habitat, the axolotl is one of the most studied creatures on the planet due to its strange longevity (up to 15 years) and its ability to regenerate almost all parts of its body, including parts of its brain. So the animals are bred and maintained for research, and are also popular in hobbyist fish tanks.

Efforts have been underway for years to protect the axolotl’s native environment, but at this point, the IUCN Red List only lists a few dozens of the salamanders living in the wild.

Tenochtitlan on Lake Texcoco Source: Tectonica

Tenochtitlan on Lake Texcoco, the site of the future Mexico City.
Source: Tectonica

It’s the 205th anniversary of Darwin’s birth today. In thinking about what Darwin might have thought about conservation efforts and endangered species lists, I came upon this quote by Peter Ward. Ward has compared human impact on the environment and world’s species to that of the presumed asteroid that led to the extinction of the dinosaurs, saying that this time, humans are the asteroid.

On this topic, he said, “If we were to go back about 63 million years ago and look at a very tiny rat-sized mammal that would give rise to all of the rest of the primates, it would be very difficult for us to say, Well, there is the future of intelligence on this planet. That tiny rat-sized creature would look anything but intelligent.

“The point, to me, is that species not only have an inherent value in the present day, but they have a future, that we cannot tell where the next global intelligence, if there’s going to be one, will come from. We do not know what species will give rise to some charismatic group, or some very important group. If we take the long view, the millions-of-years view, then we must not only think about species’ value, but future species’ value.”

Axolotl (Ambystoma mexicanum)

Axolotl (Ambystoma mexicanum)

Darwin spoke of the success of species in terms of survival, but what would have made of the axolotl’s circumscribed type of survival.

And what would Darwin, who studied past extinctions but still lived in world where it must have been virtually unimaginable to envision the disappearance of the vast rainforest, the plentiful wildlife on land and on sea, the abundant amounts of fresh water, what would Darwin have had to say about whether the current wave of extinction could be considered a force of ‘natural selection’?

Charles Darwin (age 29)

Charles Darwin (age 29)