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Thursday, December 17, 2020

Accidentally Domestic

"The first rule of intelligent tinkering is to save all the pieces."

- Aldo Leopold

Genetics has been one of the most exciting (for people who aren't me) frontiers in zoo biology.  The understanding of inbreeding and the need for genetic diversity, pioneered by Rawls and Ballou in the 1970's, completely restructured how zoos interacted with one another, going from competitors and rivals to partners in collaborative breeding programs.  The sciences of cloning, gene-banking, cryopreservation, and assisted reproduction have potential to impact the facts of many endangered species.  It's worth remembering that genes didn't just come into being in the last century or so.  They've always been a part of us (and our animals), and what we've done has always had an impact on the genetic level, going back to the beginning of time... for good and for ill.

Our earliest experiments in genetic management of animals go back thousands of years, to when our ancestors domesticated the first animals.   The differences between modern domestic animals and their wild ancestors are extraordinary.  A Chihuahua bares little resemblance to a grey wolf, a cochin chicken is very different from a red junglefowl, and the domestic horse and cow are all that we have left of their now-extinct wild progenitors.  No one who tried turning a mouflon into a domestic sheep, with a woolly coat for shearing, had understanding about genes - they just bred animals that they liked, resulting in animals which they liked even more.

There is the potential for the same to occur with zoo animals - albeit accidentally.


Evolution is the process of genetic changes in a population, and evolution can be shaped by unnatural forces as well as natural ones.  Suppose zoos and aquariums, intentionally or subconsciously, starting breeding certain animals with certain traits.  Maybe they favor breeding males that are less aggressive and easier for keepers to work around.  Maybe the animals who are less afraid of the keepers are able to get more food (since they won't be hiding or running when diets are put out), making them stronger and better breeders than their more skittish exhibit-mates.  There certainly has been a bias in the past for breeding animals with unusual colors or patterns, such as white tigers or albino Burmese pythons.  Intentionally or not, zoo managers can shape future generations.

This has been done deliberately with wild animals.  We don't want to live with wolves and wild cats, we want to live with domestic dogs and cats, and have changed those species accordingly.  We've been our own evolutionary force that has molded those animals.  But with zoo animals, we should want the opposite - in a sense we want to freeze evolution.  Ideally, a tiger in a zoo in the year 2100 would be indistinguishable from one in the wild.  This is especially important for species which we hope to return to the wild someday.

Conservation doesn't just take place on the level of ecosystems and species - it takes place on the genetic level.  If we turn wild animals in zoos into something new - a quasi-domestic species, fit for life in a zoo but nowhere - we lose a piece of the natural world, and we may never get it back.

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