Biotech can’t bring ‘em back alive without DNA
From ANIMAL PEOPLE, September 1997:
Noah, as Stephen Tello of Primarily Primates points
out, was both the first known zookeeper and––perhaps due to
job stress––the first winemaker.
He also ran the first captive breeding program.
According to the Biblical prescription, he needed just two of
each species. Genetic diversity apparently took care of itself.
Sometimes captive breeding to recover endangered
species works that easily, but more often not. In real life,
when some animals are paired at the wrong time, one eats the
other. Such considerations inhibit pairing only the second
female Cape pygmy rock lobster found in 200 years, discovered
in May, with a male found one month earlier. Both turned
up near East London, South Africa. Only one other female and
14 other males have ever been seen.
Model-maker Ian Hughes of the Dudley Zoo in
England recently saved the tiny triop Cancriformis shrimp
through captive breeding, of a sort. Believed to be the world’s
least evolved multicellular animal, the triop lays eggs that can
live up to 15 years before hatching, but wild triop habitat is a
single pool, closely protected by the conservation group
English Nature. Eggs from the pool were sent to many zoos
and scientists. The Wildfowl and Wetlands Trust at Merton
Mere managed to hatch a few, but Hughes hatched 10,000 on
his office window sill.
While recovery projects for high-profile species such
as the California condor cost millions of dollars, successful
recoveries of more obscure species tend to be done on a shoestring,
often by amateurs, because more resources aren’t available.
Nature Conservancy president Stephen Packard, for
instance, acclaims former insurance company engineer Ron
Panzer, of Joliet, Illinois, as the “guru of prairie insects” and
pioneer of invertebrate reproduction. Panzer took up entomology
in 1978, rediscovered the rattlesnake master moth in 1988,
50 years after anyone else had reported one, successfully breding
the moths in captivity, and has since reintroduced them to
four Chicago-area grasslands. Panzer has also captive-bred and
released rare grasshoppers, butterflies, and froghoppers to one
site, the Nachusa Grasslands, near Dixon.
But advanced genetic technology is updating the
risky two-by-two approach. John Mulvihill, a pub owner in
Glenbeigh, Ireland, availed himself of genetic research by
thoroughbred expert John Flynn in his apparently successful
effort to save the Kerry bog pony. The pony was believed to
have died out around a century ago, but thinking some might
persist, Mulvihill canvased horse fairs until he found an old
pony and mare with the right characteristics. They now have
62 descendants, including 20 registered studs.
Mulvihill used genetic science only to confirm the
uniqueness of the bog pony breed. U.S. Fish and Wildlife
Service DNA specialist Mary Burnham-Cirtis is similarly using
genetic data, taken from preserved and stored scales of the
allegedly extinct Great Lakes blue pike, to see if blue-colored
pike found in Minnesota and Canada are the same species. If
so, the blue pike may be restored to Lake Erie and Lake
Ontario. Although one specimen was caught in 1989, the
Great Lakes blue pike was officially declared extinct in 1975,
before DNA testing was developed.
Researchers from the Smithsonian Institution and the
Molecular Genetics Laboratory at the National Zoo recently
used DNA to identify not-quite-fossilized 3,000-year-old bones
found in Hawaiian lava flows as having come from Laysan
ducks, a close relative of mallards. The fossils showed that the
ducks formerly lived throughout Hawaii, not just on Laysan,
at altitudes from sea level to 5,000 feet. That upset the old
hypthesis that Laysan ducks were uniquely adapted to their
only current habitat, a brackish pond on Laysan, which supports
a population of just 150. Thus Laysan ducks perhaps can
be successfully reintroduced to other habitats.
Hopes that extinct species can be restored from preserved
genetic material, however, may be premature.
Japanese researchers have attracted note but no success as yet
with attempts to clone woolly mammoths and modify the genetic
structure of chicken embryos to recreate the moa.
Claims that ancient DNA may be recovered from fossils
have been advanced by George Poinar of the University of
California at Berkeley and others, whose purported finds have
included DNA from a 125-million-year-old beetle, a 25-million-year-old
termite, and a 17-million-year-old magnolia leaf,
all preserved in amber. There have even been
claims of DNA being recovered from deep inside
the hipbone of tyranosaurus rex. But further
study by Jeremy Austin and team at the Natural
History Museum in London indicates that the
DNA in each instance came from contamination––chiefly
by ambient fungi and tiny flakes of
skin from the researchers’ own hands.
Further, even genetic material collected
relatively recently has often deteriorated
beyond recovery, Australian expert Ian Gunn
told the Australian Veterinary Association in
May. Gunn cited the Tasmanian tiger as an
example of a species possibly lost because of
deficiencies in the storage of cells from the last
known specimen.
Even techniques commonly used in agriculture may
not succeed in reproducing rare and endangered species. The
Rare Breeds Conservation Society thought it knew how to conserve
wild shorthorned cattle from genetic material when the
New Zealand Department of Conservation several years ago
slaughtered a herd of 40 who had been marooned on Enderby,
one of the sub-Arctic Aukland Islands, since about 1850––but
semen taken from several bulls shortly after they were killed
has failed to impregnate the sole survivor, a then-young cow.
Fifty Agente de Champagne or French blue rabbits removed
from the island bred up to 90, but successful reproduction then
stopped apparently due to inbreeding, RBCS president Michael
Willis frustratedly announced in February.
At present, the only firm promise of genetic technology
in endangered species recovery involves improving the
odds for animals not yet lost, like the Japanese ibis, saved by
injecting cell tissue into the eggs of another breed of ibis.
Gunn and others maintain tissues from about two
dozen endangered Australian animals at the Animal Gene
Storage and Resource Centre at Monash University in Victoria.
But the best way to preserve endangered species is still preserving
adequate populations in multiple wild habitats, just as the