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slash scishow to learn more when you
picture a parrot you might imagine it in
a tropical forest in the Amazon or an
island in the Pacific
you probably don't picture Denver but up
until only a century ago the United
States was home to its very own species
of parrot the Carolina parakeet parrots
are generally speaking birds of the
order City so for meas this includes
macaws parakeets cockatoos and others
these birds are really native to much of
the United States one or two Central
American species make it just north of
the Mexican border and a bunch of others
have been introduced as released pets at
the Carolina parakeet conure OPS's
carolina ANSYS was endemic to the u.s.
meaning it lived nowhere else
they were small colorful birds around a
hundred grams in weight with green
bodies yellow heads and orange faces
they were most commonly found in the
trees along rivers and swamps gathering
by the hundreds and infamously noisy
flocks according to historical reports
they could be found as far north as New
York South to Florida and west to
Colorado it was around the mid-1800s
that the birds went into a sharp decline
and not long into the 20th century they
became entirely extinct in the wild the
last captive Carolina parakeet died in
the Cincinnati Zoo in 1918 in the very
same cage that the last captive
passenger pigeon had died just four
years prior but even though these birds
are gone we can still learn a lot about
them from what we have left at least 720
skins and 16 skeletons of Carolina
parakeets are still preserved in museum
collections around the world those
specimens not only help us understand
the birds anatomy they can also preserve
the birds DNA seriously you'd be
surprised how long that stuff can last
in a study published in 2019 researchers
sequenced the genome of one such
Carolina parakeet specimen unlocking
clues to some lingering questions about
how the birds lived and died for example
the birds were famous for eating a plant
called cocklebur which is fun because
cockle burrs are very toxic
in fact the birds ate so much of it that
according to historical reports it made
them poisonous cats were even reported
to have died from eating birds that ate
the plant in the new DNA analysis the
researchers noticed unusual mutations in
two genes the genes code for proteins
that carry energy
mitochondria and other parts of the cell
what's interesting is that these two
proteins are specifically disrupted by
cocklebur toxin interfering with the
cell's ability to function exactly what
those mutations do isn't clear yet but
it could be some sort of genetic
resistance to the plants poisons a small
change that allowed these parakeets to
thrive on a specialized diet
unfortunately a diet of literal poison
was nothing compared to the effects of
living alongside humans we don't know
exactly why the Carolina parakeet went
extinct but most researchers agree that
humans are at fault between hunting the
birds and destroying their habitat but
well we're pretty confident they're gone
we don't know if their decline was
slowed in response to various pressures
or if they went out like a light see if
a species slowly dwindles over time we
would expect their DNA to show evidence
of inbreeding and low genetic diversity
as their populations gradually shrink
this new study was on the lookout for
large chunks of the genome where each
chromosome and a pair had identical gene
variants this would suggest the birds
recent ancestors were so closely related
that they shared a bunch of the same DNA
these effects can cause a species to go
into a spiral towards extinction as
their gene pool dwindles but the new
research found no evidence of this the
Carolina parakeet sixth inge ssin
doesn't appear to have been slowed
instead as the authors of the new study
put it the extinction happened so
quickly that it left no traces in their
genomes this is pretty good evidence
that human activity in the 1800's was
the leading cause of their disappearance
not some vulnerability inherent to the
parakeet parrots are in a bad way more
than half of all living species are in
decline and almost 1/3 are considered
globally threatened with extinction
based on this research it seems the
Carolina parakeet was so devastated by
human activity that its genetic code
left little evidence of decline by
studying other extinct species with
different patterns of extinction we can
be better equipped to detect human
impacts on modern species and to spot
the warning signs before it's too late
the United States may never have another
endemic parrot and that's on us but the
least we can do is learn from this
tragedy and preserve the noisy colorful
birds still with us
the people who solved this parrots
genome had to know both biology and how
to make a computer do biology for them
the better we get at sequencing DNA the
more data there is to handle enter the
field of computational biology brilliant
org offers
whole course in computational biology
where you can learn how to process the
vast amounts of information 21st century
methods have created these are great
skills to have if you want to enter the
field or just understand where data like
what we talked about today comes from
all of brilliance courses are designed
to help you hone your math and science
skills and you can find a wide selection
covering things like stats in computer
science they're all interactive and
hands-on to the first 200 people to sign
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it's right for you
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