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# Notes on the Insane Biology of Dragonflies
- URL: https://www.bramadams.dev/202301032147/
- Published: 2023-01-28T09:30:12.000Z
- Updated: 2023-03-03T18:28:04.000Z
- Description: What can we learn from the incredible biology of dragonflies?
- Author: Bram Adams
- Tags: youtube-notes, biology

```timestamp-url
 https://www.youtube.com/watch?v=iJi61NAIsjs&ab_channel=RealScience

```

```timestamp
 00:59

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most animals succeed at the hunt <60% of the time

```timestamp
 02:48

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a dragonfly is an odonate -- extinct ones had 70cm wingspans

```timestamp
 04:13

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dragonflies have muscles that directly connect to their wings

```timestamp
 05:20

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phased stroking is used for forward flight -- at 50km/h

```timestamp
 06:12

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dragonflies can fly backwards

```timestamp
 07:15

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pterostigma acts as a counterweight to flight

```timestamp
 09:30

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can see orange to ultraviolet

```timestamp
 10:30

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fly close to water for higher contrast for prey against a blue sky

```timestamp
 11:35

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dragonflies play tracking to predict prey

```timestamp
 13:02

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humans can learn interoception ^d31494

```timestamp
 14:37

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less oxygen, smaller animals

```timestamp
 15:06

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dinosaurs may have outcompeted larger dragonflies

---

## On Coal Forests

Huge dragonflies lived off of higher O2 air content

> **Coal forests** were the vast swathes of wetlands that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times.\[1\]\[2\] As vegetable matter from these forests decayed, enormous deposits of peat accumulated, which later changed into coal.  
> **Much of the carbon in the peat deposits produced by coal forests came from photosynthetic splitting of existing carbon dioxide, which released the accompanying split-off oxygen into the atmosphere**. This process may have **greatly increased the oxygen level, possibly as high as about 35%, making the air more easily breathable by animals with inefficient respiratory systems**, as indicated by the size of Meganeura compared to modern dragonflies. [(View Highlight)](https://en.wikipedia.org/wiki/Coal%5Fforest?ref=bramadams.dev)

![https://bram-adams.ghost.io/content/images/2023/03/big-dragonfly-for-scale.png](https://storage.ghost.io/c/0c/cc/0ccc9a8d-054a-4056-b11e-e1bfbbb66387/content/images/2023/03/big-dragonfly-for-scale.png)

big dragonfly for scale.png