hybrid species
The
very day I wrote my short message on interspecies relationships between
animals, The New York Times Magazine published
a short, but fascinating essay on animal hybridization by Moises
Velasquez-Manoff, titled “Lions and Tigers and Bears.”
The article began with what seemed like
perhaps somewhat innocuous information, that the increase of forested land in
the US New England region had seen a remarkable resurgence of animals once
perceived to be dwindling in numbers, including moose, turkeys, beavers, and
white-tailed deer, the later of which are now so “numerous that they are often
considered pests.”
The area has also been reinhabited by what
was once called the Eastern wolf, formerly hunted and poisoned out of
existence. But the new species of wolves are not precisely what they seem, but
often represent an interbreed of Great Lake wolves who have long mated with
local coyotes. Some of the original wolves, moreover, migrated to Canada, who
bred with the eastern-pushing coyotes, and their descendants, in turn,
interbred with other coyotes and dogs. The result is what some call the
“coywolf,” a new breed of animal, evolved over just a few decades that have
taken advantage of the pack hunting instinct and more social nature, but also,
like coyotes have been able to thrive in areas around human beings.
With the increasing catastrophes of
global warming and even temporary fluctuations in regional areas, it has become
apparent that a number of such new species have begun to evolve, including
hybrids of dolphins, fish, finches, bats, lynx, squirrels, and bears—the last
creating a mix of grizzly and polar bears, whose habitat is particular
endangered.
For generations the prevailing wisdom
among scientists, Velasquez-Manoff asserts, was that hybridity was a
“lineage-ending mistake,” often with the outcome of sterility, as in the famed
case of the mating of donkeys with horses—resulting in “evolutionary duds.”
Just as Charles Darwin had argued for the
increasing unpopular view of animal intelligence, so too did he devote an
entire chapter in his Origin of the
Species to hybrids. While 20th century scientists increasingly
came to define species as the all-important distinction between animal
differentiation, Darwin was not clear in his definition of precisely what a
species meant: “he was vague on how to define species, referring to ‘the vain
search for the undiscovered and undiscoverable essence of the term.’”
But throughout the early and mid-20th
century, the concept of species became increasingly reified as the one author
wrote in 1930, “the greatest blunder in sexual preference which we can conceive
of.”
No one yet knows precisely where these new
hybrid species will lead, or whether or not hybridization will help animals
threatened by human beings directly and through our transformation of nature to
better survive. Will hybridization erode biodiversity, preserve it, or augment
it—or effect some combination of these alternatives?
We human beings might look for an answer
to our own species, who, when forced to leave the sub-Saharan African continent
to move into Eurasia, sometimes mated with another related species, the
Neanderthal, whose genes nearly all of us—except sub-Saharan Africans—carry
today within our genes.
Los Angeles,
August 19, 2014
Reprinted
from Green Integer Blog (August
2014).
source: the new
york times magazine, august 14, 2014