4 Mysterious Extinctions from Earth’s History

Nowadays, we're pretty confident about how the dinosaurs died out, but there are still other extinctions throughout Earth's history, some big, some small, that remain unsolved.

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[oOcattyOo]

I just want to say how glad I am that SciShow isn’t full of over-dramatic background music. It’s my pet peeve when watching non-fiction shows

[TheNighthawke]

Another theory that I've learned about regarding the Neanderthal extinction centers on their caloric intake requirements. From studying their bones, it has been estimated by scientists that they had a significantly higher muscle mass and metabolism, which then required a significantly higher caloric intake than the average homo sapiens. As a result, sapiens could survive with less food, which in colder periods (like the one where the Neanderthals disappeared from the fossil record) could easily make the difference over who survives and who doesn't. If you couple this with some of the other complementary theories about this extinction, it sadly starts to look like a recipe for disaster for the Neanderthal. 😞

[sarahferguson]

I love learning. I had never heard of the big shark extinction event or the Guadalupian event.

[brandondavidson]

Another theory for Neanderthal extinction is the opposite of why Sapiens survived so well: social structures.
Every place we've found Neanderthal fossils it tends to be small family groups, not entire tribes or nations of people.
That doesn't just affect genetic diversity but also how much people can help each other and how many resources they can find and share.

[rafaelfermin]

The latest theory about Neanderthals is pretty interesting. Apparently, given that Neanderthals were much more robust and stockier in average compared to us, that meant that their caloric ingest was slightly bigger for their survival. That explains why Neanderthals never really became that widespread because bigger groups were unable to cope with difficult conditions that were very common in those times. Also, they relied more in their physical condition than us for hunting because Neanderthal equipment was more suited for melee attacks than our equipment that was more suited for medium to long distance hunting. You combine all of those factors and you get a pretty reasonable and interesting theory.

Source: one of the latest Eons episodes

[MorgenPeschke]

I wonder if the Permian mass extinction was so bad because global biodiversity hadn't fully recovered from the Guadalupian mass extinction that preceeded it.

[Ascend]

I like that you provided less supported hypothesizes, while also explaining why they are less supported.

[dlbstl]

Graphics of the associated years of the extinctions would be helpful. Overall, this was really a cool topic and well presented. Enjoyed!

[dmanagable]

"Mysterious Shark Extinction" is my new band name.

[jakoblarok]

wait, wait, wait... *don't* we know what happened to the sharks with the non-linear denticles? In mat-sciences, didn't they find that linear denticles make it harder for bacterial colonies/mats to form; thus making the "linear denticle pattern" a viable bio-form to emulate with material science for use in hospital surfaces, and so on?...
i am susceptible to mis-remembering things, so perhaps i'm mistaken...

[longlakeshore]

A paper in 2014 theorized that a species of Asian bison crossed the Bering land bridge during the last glacial maximum. It's population exploded and ate so much grass it helped drive other grazing megafauna to extinction in the last 30, 000 years.

[PostalTwinkie]

My mother has 2% Neanderthal in her and upon finding out our thought was, "That seems like a lot." Her ancestors were from Southern Europe. In contrast my father had none and his ancestors are from Northern Europe.

What is the average % of Neanderthal in people alive today? That would be interesting to find out.

[cadenz]

For the megafauna extinction combination of climate change and isolations caused by humans over hunting in certain areas may have caused these species to be more vulnerable to resource competition with other megafauna, smaller and more adapted herbivores like deer and bison, as well as smaller gene pools may have led to their demise. Being a bigger mammal may make it harder for predators and the weather to kill you, but it means you’re a bigger target for humans, it takes longer for you to replenish your numbers due to longer gestation times which means low birth rates as well, and you need more food.

[paige]

Thanks scishow! The day this video went up I have been watching this channel for 9 years! It's been a pleasure watching the changes and growth this channel has made!

[rockinbobokkin]

I'm always happy to learn ANYTHING new about sharks. 😊

[fionagibson]

I’m always going to be sad that the glyptodonts died out. I wish I could have petted a giant armadillo.

[nzugruf]

Thanks for all the informative videos all these years. I hope that your team and SciShow never goes extinct. Seasons greetings to all of you. ❤

[stephenballard]

Since I know you like to learn things, the name of the traps in China is pronounced "EEE- May- Shan". The three syllables are each individual words, and the first is the long "E", as in "cheese". " E Mei Shan" sounds like it means "single (or solitary) beautiful mountain", but I'd have to go look it up to be sure.


Thanks for everything you teach me!

[markmyjak]

I'm starting to think extinction is part of the planet's life cycle.

[brianhester]

Rose makes a great host! Insightful and interesting...!