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It turns out the name Boaty McBoatface didn't go to waste, and the submersible now bearing the name has returned from its first mission! Also, the diversity of frogs we see today may have arisen more recently than we previously thought!

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Sources:
https://www.bas.ac.uk/media-post/boaty-mcboatface-returns-home-with-unprecedented-data/
https://phys.org/news/2017-01-rapid-arctic-shifted-southern-ocean.html
https://www.eurekalert.org/pub_releases/2017-07/fmon-eet063017.php
http://dx.doi.org/10.1073/pnas.1704632114
http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2012.01715.x/full

Images:
https://commons.wikimedia.org/wiki/File:RRS_James_Clark_Ross_Rothera.jpg
https://commons.wikimedia.org/wiki/File:Antarctic_bottom_water.svg
https://commons.wikimedia.org/wiki/File:Impact_event.jpg
https://commons.wikimedia.org/wiki/File:Tropical_forest.JPG
https://commons.wikimedia.org/wiki/File:Litoria_xanthomera_tadpole.jpg
[Music]

Remember how last year, the UK's National Environment Research Council decided to let an online poll pick the name of their snazzy new ship? And the internet being the internet latched on to the name Boaty McBoatface. The scientists at the research council said, no thanks, and named the ship after David Attenborough. 

But they didn't completely turn their noses up at the name Boaty McBoatface. They gave it to a remotely controlled submarine.

And good news, Boaty just returned to the Uk from its 7 week maiden voyage with the RRS James Clark Ross. Together they explored the Orkney Passage. An extremely deep, cold region of ocean 500 miles off the Antarctic Peninsula.

And the information they brought back will hopefully teach us more about climate change. The scientists on the mission used Boaty to collect data three times with some help from instruments anchored to the sea floor and some deployed from the ship. They were looking at the water's temperature, how fast it was flowing, and how much turbulence was happening. Boaty did encounter a bit of trouble, like a school of krill so dense it tricked the submersible's echo sounders which use sonar to tell how far down the ocean's bottom is. But overall, its missions were successful.

Having all this data on what's happening in remote Antarctic waters is really important because it helps us figure out how the mixing of ocean currents affects and is affected by climate change.

A current called the Antarctic Bottom Water forms off the coast as surface water is cooled by cold Antarctic winds, becomes denser and sinks to the bottom of the ocean. And as this cold mass of water moves northward, it plays a big role in keeping oceans circulating around the globe. But the winds are changing. Literally.

Shifting temperatures in the Northern Hemisphere affect how air moves all over the Earth, especially the winds over Antarctica. And these winds affect the speed of the Antarctic Bottom Water current, which affects how turbulent its flow is. This means it's mixing with more warm water from the upper layers of the ocean, and it's not as chilly as it heads towards the Equator.

By studying places like to Orkney Passage, which is how this deepwater current travels to the Atlantic Ocean, researchers can start to learn how much the winds are affecting the water. Scientists can incorporate this new data into climate change models, giving us a more accurate idea of where weather patterns may be headed in the future. 

So thanks, Boaty McBoatface for braving the depths of the Antarctic Ocean to bring us info on how our planet is changing. 

And in the meantime, some scientists were plumbing in the depths of frog DNA. Nearly 90% of the world's amphibian species are frogs. There are more than 6000 species of them, and they're found on every continent except Antarctica. 

So where did all these frogs come from?  Well, a group of Chinese and American scientists just published a massive new study of the evolutionary history of frogs and the answer they found has to do with dinosaurs.  With a technique called divergence time analysis, scientists can use DNA to estimate when two evolutionary lineages split off from each other based on the genetic differences they've built up.  

Previous big studies suggested that the golden era of frog diversification was about 100 million years ago, but they only used small bits of DNA for their analysis, up to 12 genes max.  This study blew those out of the water, looking at 95 protein coding genes with data from 309 different frog species and it came to a different conclusion.

 It turns out that frog diversity actually took off much more recently, after the end of the Cretacious period 66 million years ago.    There was a mass extinction event that killed off the dinosaurs and many frog species, too, that left all sorts of ecological niches suddenly open.  The researchers found that the three biggest frog groups, hyloidea, microhylidae, and natatanura, which make up almost 90% of frog species in the world today, all went through an explosion of diversification after the end-Cretaceous extinction.  

Two evolutionary innovations let the still-living frogs prosper after the dinos were gone.  First, they moved into the trees.  Angiosperms, the flowering plants of today, bounced back and grew into full-fledged forests that created new habitats and opportunities.  Second, some of the nixed the tadpole stage of life so that fully developed adults hatch from eggs, which cut down on the need for a body of water to grow up in.  

So despite what you learned in elementary school, about half of today's frog species don't have tadpoles.  This study also includes a ton of information about where all these frog lineages arose in the world and how they're related to each other.  So you could say that our knowledge of life on Earth took a big hop forward.

Thanks for watching this episode of SciShow News and thanks especially to all of our Patrons on Patreon who make this show possible.  If you wanna help us keep making videos like this, go to Patreon.com/SciShow and don't forget to go to youtube.com/scishow and subscribe.

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