Ever wonder how whales, dolphins, seals, walruses, and manatees went from land to sea? This video covers the major groups of marine mammals and the progession of key species in each group during the transition from being terrestrial to aquatic animals. And you will NOT believe how many independent times mammals evolved to go back to sea! I know because I couldn't believe it either! I hope you enjoy learning about marine mammals evolution as much as I did! ;D

References: Earth System History: https://amzn.to/3v1Iy0G
Uhen, 2007: review over marine mammal evolution- https://doi.org/10.1002/ar.20545
Berta, Sumich, and Kovacs, 2015: Marine Mammals: Evolutionary Biology- https://amzn.to/41fEsUd

0:00 All animal groups have gone back to sea
0:51 Marine Reptiles
2:26 Aquatic & Sea Birds
2:43 Marine Mammals
3:59 All Mammal Groups That Went to sea
5:35 Whales Journey to Sea
9:26 Manatees & Dugongs Journey to Sea
11:44 Seals & Walruses Journey to Sea
15:06 Polar Bears & Sea Otters
16:43 Coinciding Evolution of Marine Mammals
17:30 Future of Marine Mammals?

GEO GIRL Website: https://www.geogirlscience.com/ (visit my website to see all my courses, shop merch, learn more about me, & donate to support the channel if you'd like!)

Hey there, Earth enthusiast! Check my favorite Earth-friendly products:
Bamboo toilet paper: https://shrsl.com/3cvku
Bamboo paper towels: https://shrsl.com/3cvkw
Compostable tableware: https://shrsl.com/3cvkz
Compostable trash bags: https://shrsl.com/3cvl0
Bamboo cutlery + straw! : https://shrsl.com/3cwfl
Eco-Friendly Tote (great for grocery shopping!): https://shrsl.com/3cwfp
Reusable straws + cleaning brushes (my fav!): https://shrsl.com/3cwft
Eco-friendly laundry detergent: https://shrsl.com/3cwgo

Directly offset your carbon footprint with Wren: https://shrsl.com/3d0t2
(Just click link, press get started, take the free C footprint quiz, then choose how much you want to reduce your footprint by donating to the C sequestration projects they're funding!)

Non-textbook books I recommend:
Oxygen by D. Canfield: https://amzn.to/3gffbCL
Brief history of Earth by A. Knoll: https://amzn.to/3w3hC1I
Life on young planet by A. Knoll: https://amzn.to/2RBMpny
Some assembly required by N. Shubin: https://amzn.to/3w1Ezm2
Your inner fish by N. Shubin: https://amzn.to/3cpw3Wb
Oxygen by N. Lane: https://amzn.to/3z4FgwZ
Alien Oceans by K. Hand: https://amzn.to/3clMx1l
Life's Engines: https://amzn.to/3w1Nhke

Tools I use as a geologist/teacher/student:
Geology field notebook: https://amzn.to/3lb6dJf
Geology rock hammer: https://amzn.to/3DZw8MA
Geological compass: https://amzn.to/3hfbdLu
Geological hand lens: https://amzn.to/3jXysM5
Camera: https://amzn.to/3l6fGRT
Carbon-neutral pencil bag: https://shrsl.com/3cvjv
Carbon-neutral backpack: https://shrsl.com/3cvkc

Disclaimer: Links included in this description might be affiliate links. If you purchase a product or service with the links that I provide I may receive a small commission, but there is no additional charge to you! Thank you for supporting my channel so I can continue to provide you with free content each week! And as always, let me know your topic suggestions in the comments down below!