When Diversity of Life on Earth Tripled! GEO GIRL

The Great Ordovician Biodiversification Event marked the first drastic and lasting increase in biodiversification of multicellular life on Earth! The Cambrian Explosion replaced the ediacaran fauna with Cambrian fauna and the Great Ordovician Biodiversification Event led to the replacement of Cambrian fauna with the more diverse Paleozoic fauna, which have since been largely replaced by Mesozoic-Cenozoic/Modern fauna. This event occurred in different places at different times, and thus, there were many causes. The main causes for this diverisifcation include: dispersed continents, active tectonics, orogenies, and volcanism, warmth and high CO2 levels, gradual cooling throughout the Ordovician period, planktonic diversification and increase in abundance, animal diversification itself, especially increased predator-prey relationships, and potentially even a meteor shower! There were also many impacts of this ordovician diversifiation, including more complex food webs and ecosystems with more specialied and tiered species, more multicellular reefs rather than the micrbrially dominated reefs of the precambrian, and more! I hope you enjoy learning about this event with me ;D

References:

0:00 What is the GOBE?
1:27 Leading up to the GOBE
3:06 Evolutionary Fauna Transitions
3:36 Ediacaran Fauna
4:38 Cambrian Fauna
6:11 Paleozoic Fauna
7:48 Multiple Causes of the GOBE
8:23 Warm, Nutrient-rich Conditions
10:40 Tectonics & Mountain Building
11:40 Gradual Cooling
14:46 ‘Food’ & O2 Rise
15:54 Meteor Shower
16:52 Diversification Itself
17:42 Impacts of GOBE
19:13 More Stable & Resilient Ecosystems
19:55 Reef Transition & New Food Chains
20:42 Summary

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Non-textbook books I recommend:

Tools I use as a geologist/teacher/student:

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[hazardousmaterials]

The GOBE, the GOE, the Great Dying - geologists sure like describing things as “Great!” Thank you for making learning about these events so fascinating! Your videos are really gr… terrific!

[mliittsc]

Good idea to note that gradual change (vs rapid change or no change) increases biodiversity. Rapid change kills off species who can't adapt quickly enough (which is most species), no change allows a few species to become so successful they drive other species to extinction. Gradual change allows existing species to survive through reasonably paced adaptation, while preventing any single species from getting out of hand.

[Hellbender]

YES the Ordovician is my favorite period because there's a fossilized Ordovician reef right near my house!. Recently my son (8) and I collected: 2 sizes of trilobites, worm burrows, snails, 2 brachiopod types, coral, and many shapes of bryozoans. I took him to the university to meet a paleontologist and he got to see his research (sea star osteoderms under stereomicroscope) and show a few of his exciting fossils to learn more about them . He said you'd be surprised how many people bring in stuff that's definitely not a fossil.

What do you think of this video idea: Genuine Fossils vs Things That Arent Fossils (that category includes cool textured/ shaped rocks, concretions, recent shells that arent fossilized, fake fossils made by people to sell, pieces of statue, an old shoe).

I love your videos, because I 've learned a lot from them.

[tamjammy]

Ta again. Its good to learn about the factors influencing diversification of life. And importantly, the timescales involved. When i try to talk to people about the effects of climate change on wildlife one of the commonest responses i get is that temperatures were higher in the past and life survived. Most people don't get that the rate of change is whats important.Not the change itself .This isnt helped by phrases such as "Cambrian explosion" or even "rapid diversification". Both of which imply, to non biologists / geologists something that happened overnight. It's really hard for people ( including me ) to get their heads round the sheer vastness of geological timeframes. The concept that our entire species has only been around for a blink of an eye is just so far outside of our everyday understanding of the passage of time that its hard to get across the fact that 1000yrs means practically nothing . We can but try however, and your videos do far more than most. Ta again.

[tedetienne]

Thank you! Fascinating video! I'd definitely love to learn more about the Ordovician overall. The rate of biodiversity growth during that time is matched by another time - from the Triassic–Jurassic extinction event onward to today (with one or two hiccups). From the Tr-J to today, we've had about 10 to 12 times the biodiversity growth. It's really good to hear about the times when life is doing well!

[sagaravn]

I can only recommend the podcast, Palaeocast. They do say G O B E, and have loads of interviews with really fascinating topics. I actually found you, while researching on something I'd heard there. You make everything paleontological a bit easier and give me a broader overview of all I love about the past. It's not always easy to have English as a second language. 😊

[edwardmacgregor]

As always, more to think about and more tools to think with. Thank you!

[johnnyBrwn]

Your videos make me so happy. Last geology and biology class I had was in 3rd and 9th grade respectively. Over 20 years ago. With so much negativity in the world your videos bring me back to happy memories in my childhood. Thanks for making this. Looking forward to seeing your next videos.

[oker]

let's see here; life tripled in the Ordovician because . . . a mass extinction happened before it!

[donaldbrizzolara]

Having once done quite a bit of work on ichnofossils in the field and subsurface, I feel they often tend to be overlooked when making grand evolutionary interpretations regarding periods of extinction or diversification. Ichnologic evidence may be essential to evaluate how the interactions between organisms and substrate responded to these two major evolutionary events (CE and GOBE). Also, because trace fossils essentially represent a continuous record of soft-bodied organisms, ichnologic information may provide an independent line of evidence to that of “shelly fossils”, therefore helping to better calibrate and understand the two evolutionary radiations. Anyway….just a thought and, perhaps, it has already been evaluated in depth. Nicely done Rachel. Having listened to all your videos I feel I must be deserving of another degree in geology…one that surpasses the almost medieval one I first received 48 years ago!

[ericbrown]

🎉🎉 G.O.B.E. 🎉🎉 ❤😊❤ Go Ordovician! 🌊🐚🪼🦐🪸🦑🌊

[Kosmonooit]

Thank you, a lot of work must go into preparing these videos.

[joeanderson]

I wonder if such an event could happen again.

[ellenmcgowen]

Thanks for this delightful video! I've long wanted to hear a presentation of some more "standard" or endogenous geological explanations for the GOBE. I've heard "astronomical" speculations (e.g. dust in the plane of the solar system from an asteroid breakup that also caused the Ordovician Meteor Event; gamma rays seeding clouds as the sun passed through a star-forming region), but not the geological ones. "Gradual cooling caused by weathering from the Taconic Orogeny with resulting C burial" is the sort of explanation I was looking for!

[denmaroca]

I find your channel a short while ago; have been merrily binging on your existing videos and this is the first new video that dropped since I started. Usual detailed information (which I've been looking for). You're an excellent presenter with the ability to make the driest material lively and interesting. You should have an increasingly successful channel.
I do have one (slight) criticism. You seem a little parochial. There are regions of the world outside North America/Laurentia. You might want to describe the orogenies and other geological events happening in the rest of the planet occasionally! (Suggestion: a series of videos each covering the history of a different continent?)

[tomsmith]

great review !! I didn't know that the Ordovician era was as interesting as the Cambrian era !!

[calinradu]

After not sleeping properly for two nights in a row I was looking like Aegirocassis

[terenzo]

Another great video. More fun than Disney!

[AndreMessage-pn]

These have been amazingly helpful, thank you greatly!!

[numericalcode]

Specialization with greater ecological complexity is a great point.