The last living members of an extinct species - Jan Stejskal
-
0:07 - 0:13In the savannahs of Kenya, two female
northern white rhinos, Nájin and Fatu, -
0:13 - 0:16munch contentedly on the grass.
-
0:16 - 0:18At the time of this video’s publication,
-
0:18 - 0:23these are the last two known
northern white rhinos left on Earth. -
0:23 - 0:26Their species is functionally extinct—
-
0:26 - 0:30without a male,
Nájin and Fatu can’t reproduce. -
0:30 - 0:34And yet, there’s still hope to revive
the northern white rhino. -
0:34 - 0:36How can that be?
-
0:36 - 0:39The story starts about 50 years ago,
-
0:39 - 0:42when poachers began illegally hunting
thousands of rhinos -
0:42 - 0:45across Africa for their horns.
-
0:45 - 0:48This, combined with civil wars
in their territory, -
0:48 - 0:52decimated northern white rhino
populations. -
0:52 - 0:57Concerned conservationists began trying
to breed them in captivity in the 1970s, -
0:57 - 1:01collecting and storing semen from males.
-
1:01 - 1:05Only four rhinos were ultimately born
through the ambitious breeding program. -
1:05 - 1:10Nájin, and her daughter Fatu
were the last two. -
1:10 - 1:15In 2014, conservationists discovered
that neither can have a calf. -
1:15 - 1:20Though Nájin gave birth to Fatu,
she now has weak hindlegs, -
1:20 - 1:23which could harm her health
if she became pregnant again. -
1:23 - 1:27Fatu, meanwhile,
has a degenerated uterine lining. -
1:27 - 1:34Then, the last northern white rhino male
of the species, Sudan, died in 2018. -
1:34 - 1:38But there was one glimmer of hope:
artificial reproduction. -
1:38 - 1:43With no living males and no females
able to carry a pregnancy, -
1:43 - 1:47this is a complicated and risky process
to say the least. -
1:47 - 1:51Though scientists had stored semen,
they would have to collect the eggs— -
1:51 - 1:57a complex procedure that requires a female
to be sedated for up to two hours. -
1:57 - 2:00Then, they’d create a viable embryo
in the lab— -
2:00 - 2:05something that had never been done before,
and no one knew how to do. -
2:05 - 2:07Even that was just the beginning—
-
2:07 - 2:10a surrogate mother
of another rhino species -
2:10 - 2:13would have to carry the embryo to term.
-
2:13 - 2:17Females of a closely related species,
the southern white rhino, -
2:17 - 2:21became both the key to developing
a rhino embryo in a lab -
2:21 - 2:25and the leading candidates
for surrogate mothers. -
2:25 - 2:30Northern and southern white rhinos
diverged about a million of years ago -
2:30 - 2:34into separate— though still
closely-related— species. -
2:34 - 2:38They inhabit different regions, and have
slightly different physical traits. -
2:38 - 2:42In a fortunate coincidence,
several female southern white rhinos -
2:42 - 2:45needed treatment
for their own reproductive problems, -
2:45 - 2:49and researchers could collect eggs
as part of that treatment. -
2:49 - 2:53In Dvůr Králové Zoo in October 2015,
-
2:53 - 2:59experts of IZW Berlin began collecting
eggs from southern white rhinos -
2:59 - 3:05and sending them to Avantea, an animal
reproduction laboratory in Italy. -
3:05 - 3:12There, scientists developed and perfected
a technique to create a viable embryo. -
3:12 - 3:14Once they mastered the technique,
-
3:14 - 3:20researchers extracted Nájin and Fatu’s
eggs on August 22, 2019 -
3:20 - 3:22and flew them to Italy.
-
3:22 - 3:25Three days later, they fertilized
the eggs with sperm -
3:25 - 3:28from a northern white rhino male.
-
3:28 - 3:32After another week, two of the eggs
made it to the stage of development -
3:32 - 3:36when the embryo can be frozen
and preserved for future. -
3:36 - 3:41Another collection in December 2019
produced one more embryo. -
3:41 - 3:48As of early 2020, the plan is to collect
Nájin and Fatu’s eggs three times a year -
3:48 - 3:50if they’re healthy enough.
-
3:50 - 3:52In the meantime,
researchers are looking for -
3:52 - 3:55promising southern white rhino
surrogate mothers— -
3:55 - 3:59ideally who’ve carried a pregnancy
to term before. -
3:59 - 4:02The surrogacy plan
is somewhat of a leap of faith— -
4:02 - 4:05southern and northern white rhinos
have interbred -
4:05 - 4:10both during the last glacial period
and more recently in 1977, -
4:10 - 4:14so researchers are optimistic
a southern white rhino -
4:14 - 4:17would be able to carry
a northern white rhino to term. -
4:17 - 4:21Also, the two species’ pregnancies
are the same length. -
4:21 - 4:25Still, transferring an embryo
to a rhino is tricky -
4:25 - 4:27because of the shape of the cervix.
-
4:27 - 4:30The ultimate goal,
which will take decades, -
4:30 - 4:34is to establish a breeding population
of northern white rhinos -
4:34 - 4:37in their original range.
-
4:37 - 4:40Studies suggest that we have samples
from enough individuals -
4:40 - 4:45to recreate a population with the genetic
diversity the species had a century ago. -
4:45 - 4:48Though the specifics
of this effort are unique, -
4:48 - 4:52as more species face critical endangerment
or functional extinction, -
4:52 - 4:56it’s also an arena for big questions:
-
4:56 - 5:00do we have a responsibility to try
to bring species back from the brink, -
5:00 - 5:04especially when human actions
brought them there in the first place? -
5:04 - 5:07Are there limits to the effort
we should expend -
5:07 - 5:10on saving animals threatened
with extinction?
- Title:
- The last living members of an extinct species - Jan Stejskal
- Speaker:
- Jan Stejskal
- Description:
-
View full lesson: https://ed.ted.com/lessons/the-last-living-members-of-an-extinct-species-jan-stejskal
In the savannahs of Kenya, two female northern white rhinos, Nájin and Fatu, munch contentedly on grass. They are the last two known northern white rhinos left on Earth. Their species is functionally extinct— without a male, they can’t reproduce. And yet, there’s still hope to revive the northern white rhino. How can that be? Jan Stejskal dives into the science of reviving a dying species.
Lesson by Jan Stejskal, directed by Denis Chapon.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:11
Elise Haadsma approved English subtitles for The last living members of an extinct species | ||
Elise Haadsma accepted English subtitles for The last living members of an extinct species | ||
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