Resurrection Biology:
Project De-Extinction
By Wing In Chau
鄒穎姸
De-extinction –
not to be confused
with cloning
Cloning is a process
that requires cells to be
transferred from a living
specimen. De-extinction,
on the other hand,
involves editing the DNA
of existing animals that
are genetically similar to
the extinct animal, which
results in a ‘chimera’.
不要將「逆滅絕」(de-extinction)與「克隆」
(cloning)混為一談
「克隆」過程中會從仍存活的實驗體抽取細胞；
而「逆滅絕」是通過改造與滅絕物種相近的現存物
種的基因，產生嵌合物種。
The
passenger pigeon once thrived in
North America as the most abundant bird species
until the early 20th century. Persistent poaching and
destruction of their natural habitat via deforestation
led to their eventual extinction, with the last of its
known species to die in captivity by 1914. But almost
a hundred years later, the passenger pigeon may
be making a comeback.
Believe it or not, the concept of bringing the
extinct back to life in science fiction movies such
as Jurassic Park is not as far-fetched as one might
think. Resurrecting dinosaurs is undoubtedly out of
the question, but scientists may be able to revive
animals that have not been extinct for that long,
thanks to cutting-edge technology in genetic
engineering.
Scientists at the University of California, Santa
Cruz, have obtained genetic
data from stuffed passenger
pigeons and its closest
relative, the band-
ta i l ed p i geon ,
t h e l a t t e r
of which will ser ve as a DNA blueprint to the
incomplete and contaminated DNA of a bird that
died more than a centur y ago. Modifying the
DNA of the genetic cousin to match that of the
passenger pigeon, injecting the cell into another
pigeon’s egg and then hoping this cell will develop
into a young pigeon is probably their best bet.
The most difficult and time-consuming part of this
endeavour is genome mapping – while the two
species are closely related, their genomes still differ
at possibly millions of locations and these need to
be determined [1]. If all goes according to plan
though, we may be seeing a chimeric version of the
passenger pigeon once again in the near future.
In an even more ambitious project, some
scientists have been working on bringing perhaps
the most iconic extinct animal back to life – the
woolly mammoth – four thousand years after they
disappeared off the face of the Earth. Also using
genome sequencing, scientists have been able to
figure out what makes a mammoth
a mammoth, as opposed to
an elephant for instance.
It is with hope that using
this information, alleles
in the elephant DNA
can be replaced by
those that expres s
m a m m o t h - l i k e
fea t u r e s , s uch a s
thei r large tusks or
character istic fur r y
bodies, hence bringing
a woo l l y mammot h
back from the dead.
I f th i s were pos s ibl e,
a who l e ho s t o f et h i ca l
q u e s t i o n s accompa ny t h e
chal lenges of de-ex tinction. If de-ex tinction
succeeded and a mammoth were to be created
through a surrogate elephant mother, it would most
likely be brought up in captivity, a non-ideal way
to bring up a social animal (if they are anything like
elephants), while being the only mammoth alive. In
復活生物：
逆滅絕計劃
