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In the search for longevity, scientists have found the longest-lived vertebrates on the planet in the arctic. Meanwhile, in warmer climes, the FDA approves a new method for combating disease-carrying mosquitoes.

Learn more about Bowhead Whales:
https://www.youtube.com/watch?v=oOjYT9EqH5E

Learn more about Why We Age and How We Can Stop It:
https://www.youtube.com/watch?v=jqCo-McgHLw

Hosted by: Hank Green
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Sources:

Mosquitoes
http://www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm490246.htm
http://www.fda.gov/downloads/AnimalVeterinary/DevelopmentApprovalProcess/GeneticEngineering/GeneticallyEngineeredAnimals/UCM514698.pdf
http://www.fda.gov/downloads/AnimalVeterinary/DevelopmentApprovalProcess/GeneticEngineering/GeneticallyEngineeredAnimals/UCM514699.pdf
http://www.flgov.com/2016/08/01/gov-scott-florida-calls-on-cdc-to-activate-emergency-response-team-following-confirmed-mosquito-borne-transmissions/
http://keysmosquito.org/question-answers-on-gm-mosquitoes/
http://www.oxitec.com/programmes/united-states/
http://www.oxitec.com/programmes/cayman/
http://mosquito.ifas.ufl.edu/Mosquitoes_of_Florida.htm

Sharks
http://science.sciencemag.org/cgi/doi/10.1126/science.aaf1703
http://www.smithsonianmag.com/smart-news/how-200-year-old-whale-might-help-us-live-longer-180953813/?no-ist
http://dev.biologists.org/content/141/23/4432
http://www.bbc.com/earth/story/20141028-the-mystery-shark-of-the-arctic

Image Sources:
https://commons.wikimedia.org/wiki/File:A_bowhead_whale_breaches_off_the_coast_of_western_Sea_of_Okhotsk_by_Olga_Shpak,_Marine_Mammal_Council,_IEE_RAS.jpg
https://commons.wikimedia.org/wiki/File:Bowhead_whale_size.svg
https://commons.wikimedia.org/wiki/File:Aedes_aegypti.jpg
https://commons.wikimedia.org/wiki/File:Aedes_aegypti_larva.jpg
[SciShow intro plays]

Hank: What if you could live for centuries? Heck, what if you didn’t even have to worry about puberty until you were as old as your grandma’s grandma’s grandma? Well apparently, that’s what life is like for these animals. A study published in Science this week reports that the longest-living vertebrates on Earth may be the Greenland shark, which can live about 272 years or more! Not only is this a new record for the books, the discovery may help us learn more about our own longevity -- or lack of it.

Greenland sharks live in Arctic waters, and are mostly just a bundle of mysteries to scientists. We don’t understand a whole lot about them -- like how they develop, or even how they reproduce. So from 2010 to 2013, a team of researchers, led by a scientist from the University of Copenhagen, collected eye lenses from 28 female sharks. These lenses are really useful in studying the animals’ age, because they contain a layer called the embryonic nucleus, which is made of proteins that are made during the earliest stages of the shark’s life. So, the scientists could use Carbon-14 dating, along with some mathematical models, to estimate how old the sharks were. And they were old! Like, OLD old.

The title of longest-lived mammal goes to another Arctic species: the bowhead whale, which was an estimated 211 years old. But two of the largest Greenland sharks blew that record out of the water -- as it were -- because they turned out to be about 335 and 392 years old! And... good for them! But what’s the point of knowing that these fish are really old? Well, first of all, conservation.

Greenland sharks not only live a long long time, they also grow really slowly. It turns out that they don’t even reach sexual maturity until they’re around 156 years old! I may have been a bit of a late bloomer, but I’m glad I didn’t have to wait that long to reach puberty. So now that we know that it takes so long for them to maturity, the researchers say that commercial fisheries should be more careful about accidentally killing them, because the sharks live for a couple of our lifetimes before they can reproduce.

Plus, their genes might hold secrets to our extending our own longevity. Scientists have studied the bowhead whale, to see if they have different versions of genes than other mammals. And they found some tantalizing clues -- like duplicates of a gene involved in DNA repair, and mutations in others that may relate to aging and diseases like cancer.

We’re still not sure how these genes work together to help keep cells alive, or which small mutations can lead to big changes. So studying the genomes of Greenland sharks could give us some insights into how we can live longer. Because, y’know, dying isn’t fun.

But you know whose death I’m totally OK with? Mosquitoes. Last Friday, the U.S. Food and Drug Administration approved a trial to release genetically modified mosquitoes in Key Haven, Florida, so that eventually, there will be fewer mosquitoes there. Now, you might hear genetically modified and think that they’re, like, mutant-super-dangerous-fluorescent-red mosquitoes. Actually, they are a little bit fluorescent red.

But they are here to help humans, not themselves. These insects are engineered by the company Oxitec, whose goal is to reduce local populations of the disease-carrying species Aedes aegypti They’re the main vector, or carrier, of the Zika virus, as well as the viruses that can cause dengue and chikungunya. But how exactly are we fighting this mosquito-borne diseases by... releasing more mosquitoes?

Well, the insects that Oxitec wants to release are males that are designed to produce offspring that can’t develop to maturity. They did it by taking male Ae. aegypti mosquitoes, and plugging some artificially-constructed DNA into their genomes. This DNA contains a modified version of a gene called OX513 that makes the mosquitoes express two traits: One is a red fluorescent marker protein, so scientists can tell in a lab which mosquito larvae have the modified gene.

The other trait is that their cells produce way too much of a protein that keeps their DNA from making other proteins, so their cells just don’t work anymore, and the mosquito dies. Normally, carrying around even one copy of this gene would kill a mosquito within a couple of days. But its effects can be can be suppressed with the drug tetracycline.

So in a lab, these scientists can keep their genetically modified mosquitoes alive with the drug, until they’re released. Then, when they’re out in the wild, the gene acts like a ticking time-bomb for the mosquitoes... and also any of their offspring. The offspring will hatch like normal, but die in a couple days.

And eventually, entire generations of Ae. aegypti will shrink. The company has released these modified mosquitoes in Brazil, the Cayman Islands, Panama, and Malaysia -- and reportedly, they reduced the numbers of local Ae. aegypti mosquitoes by up to 90%! The FDA approval is just one step in a long process, so now the company has to work with the state of Florida and the local community to get the final go-ahead. But as long as the mosquitoes end up living substantially shorter lives than the Greenland sharks, I will be happy.

Thanks for watching this episode of SciShow News. And thank you especially to our President of Space: SR Foxley. Thank you so much for supporting us on Patreon and helping us do what we do! If you want to help support the show, you can check out Patreon.com/SciShow, and don’t forget to go to YouTube.com/SciShow and subscribe!