The Evolution of the Brain

The evolution of the brain began in relatively simple creatures, possibly for the purpose of coordinating digestion and other basic physiological processes. Hundreds of millions of years later, the brain evolved into the modern versions we see across the animal kingdom today. Scientists believe that humans and all other mammals evolved from fish, so by looking at the differences between human and fish brains, we can infer some of the evolutionary changes that occurred over those ~370 million years. Much of what makes our human brains unique appears to be in the cerebral cortex, though other brain structures are no doubt important in what makes us human. Finally, many of the quirks of our behavior and mental life, especially those surrounding sex and sex differences, can be explained partly by our evolutionary history.

This video is a brief exploration of brain evolution. It addresses questions like, Why did the brain evolve? How did the brain change over evolutionary time? What makes the human brain unique? And what vestiges of evolution remain hidden in our modern minds?

However, this video is ultimately incomplete. There are so many aspects of both brain and human evolution that I did not mention here or which I did not cover in detail. If you want to know more about this topic, I encourage you to check out the books, articles, and studies cited below.

Chapters:
00:00 The evolution of the brain began in creatures with simple nervous systems
01:21 Bodies evolved before brains, according to The Strange Order of Things, by Antonio Damasio
02:03 The first brains were like the enteric nervous system
02:30 Cnidarian nerve nets
03:00 Taylor Guthrie’s “Cellular Republic”
04:19 Comparing the brains of various species to human brains
05:13 Subcortical brain structures evolved before the cerebral cortex
05:44 Cortical columns in the neocortex and intelligence
06:40 Executive functions of the prefrontal cortex
07:25 David Badre on the evolution of cognitive control
09:27 The human brain is functionally holistic
09:50 Mark Humphries on the function of the cerebral cortex
11:48 Evolutionary psychology - examples of sex differences
14:18 The evolution of mental illness according to Bret Stetka
15:27 Conclusion and caveats
15:53 Thank you! Please like and subscribe!

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References:
1. Damasio, A. (2019). The strange order of things: Life, feeling, and the making of cultures. Vintage.
3. Dawkins, R. (2004). The Ancestors Tale: A Pilgrimage to the Dawn of Evolution. Houghton Mifflin.
4. Gafurov, D., & Gafurov, O. (2016). In MATEC Web of Conferences (Vol. 79, p. 01086). EDP Sciences.
5. Hawkins, J. (2021). A thousand brains: A new theory of intelligence. Basic Books.
6. Preuss, T. M., & Wise, S. P. (2022). Evolution of prefrontal cortex. Neuropsychopharmacology, 47(1), 3-19.v
7. Goetz, S. M., Weisfeld, G. Z., & Zilioli, S. (2019). Reproductive behavior in the human male. The Oxford Handbook of Evolutionary Psychology and Behavioral Endocrinology, 125-141.
8. Clutton-Brock, T. (2007). Sexual selection in males and females. Science, 318(5858), 1882-1885.
9. Stetka, B. (2021). A History of the Human Brain: From the Sea Sponge to CRISPR, how Our Brain Evolved. Timber Press.
10. Andrews, P. W., & Durisko, Z. (2017). The evolution of depressive phenotypes. The Oxford handbook of mood disorders, 24-36.

Music:
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Attribution 4.0 International (CC BY 4.0)

Attribution 4.0 International (CC BY 4.0)

Creative Commons Attribution-ShareAlike 3.0 Unported

All 3D brain animations credit: Copyright © Society for Neuroscience (2017). Users may copy images and text, but must provide attribution to the Society for Neuroscience if an image and/or text is transmitted to another party, or if an image and/or text is used or cited in User’s work.

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#howthebrainevolved #evolutionofthehumanbrain #howthebrainworks

[senseofmindshow]

⚠ CORRECTION!!! In this video, I said "this video is brought to you by the Diamond Mind Foundation." Well, as of December 2022, that is no longer the case.
For less than $5 a month, you'll get exclusive content and the satisfaction of knowing you're helping to keep Sense of Mind alive! 🧠

[sezan]

This channel is dedicated to making neuroscience and psychology clear and simple. Immediately subscribed!

[thecellularrepublic]

I'm slightly embarrassed.. Just wanted to correct myself and clarify that I mentioned in my clip that the Locus Coeruleus was the brain region in the midbrain responsible for orienting us to danger and it is actually the Superior Colliculus. Just wanted to make sure I set the record straight!

[zacharytrosch]

Hey man, this channel is going to go very far if you keep presenting information in this way. Your ideas are so well thought through and presented that makes understanding easy. Your ideas are thoughtful and interesting. Keep up the good work.

[theflaggeddragon]

Mammals did not evolve fr reptiles but instead are synapsids, a large group that included several orders more closely related yo mammals than reptiles. Reptiles on the other hand are saurapsids, and the synapsids and saurapsids diverged from more basal amniotes which evolved from early amphibians during the Carboniferous.

[thaisplouvier]

0:15 Brain originally used probably to coordinate organs
1:30 bodys preceed the brains
5:00 brain stem = oldest part of the brain
6:45 PFC is especially developed in humans. It's what allows us to engage in cognitive control, executive functions. Translate intentions and goals into action.

[ahmedelewa]

Really Deserve millions of views ..keep up

[webx]

While the evolutionary biology of gender behavior makes sense, I would be a little cautious on jumping all the way from evolutionary biology to modern human behavior. There are a few caveats.

1. A lot of modern gender behavior being referenced refers to post-agricultural societies. Post-agricultural societies represent a relatively slim subset of human behavior, despite being the populous majority. Hunter-gatherers have widely varying behavior that diverges.

2. In terms of the "selfish gene" trying to optimize its reproduction, it isn't quite as straightforward in social species as in loner species. For a loner species, it is all about the individual competing with other individuals to spread its individual genes. But in more social groups, genetic competition may be more emphasized at the group level. Instead of emphasizing individual selection, it would have emphasized tribalism.

3. Bonobos were glossed over, here. But they are an important piece of the puzzle. For bonobos, the "sexual narrative" presented here is more or less reversed. The females insist on mating with as many individuals as possible and with each other. This completely obscures paternity certainty, reducing the benefits of a strong male hierarchy. It dissolves male hierarchy by not limiting sexual access to a select few males. This drastically reduces competition, murder, and infanticide within the group. The priority is to reduce infighting.

Bonobos share genes associated with empathy and bonding that are present in the Human, but missing in the Chimp, indicating our common ancestor had these genes, and Chimps are the odd ones out. Likely because they are in direct competition with Gorillas for the same resources and territory. Creating a need for stronger hierarchies and more aggressive behavior.

4. In terms of women having restricted, selective sexuality and men wanting multiple partners, think about ancient societies. They had to create intense laws and extreme enforcement to PREVENT women from sleeping around. If women biologically mostly did not want to sleep around much, such laws would not need to be so extensive. Maternity is known, Paternity is impossible to prove until recently, unless the woman was forced to be loyal to one man.

So take some hunter-gatherer behavior into consideration:
- In several groups, the social "father" of the children is actually their uncles, rather than their biological father.
- In many groups around the Amazon, they believe women must sleep with multiple men to create a baby, so they "make the rounds".
- Resources don't generally go: Specific Hunter -> That hunter's children. Instead, an entire hunting group came back and the food was shared. in fact, they are pretty assertive about this. Look up "Fierce Egalitarianism".
- Hunters didn't provide the bulk of the food nor the most consistent food. It was important for sure. But whether or not you eat wasn't determined by who your husband was.

So this challenges a few notions:
- That women had to choose the best provider to survive
- That the survival of a man's biological children depended on his specific hunting ability

A lot of these tasks would have been diffused throughout the group. "A man's hunt" didn't provide for "his children", but that "the men's hunt" provided for "the children".

So a lot of the social pressures that lead to our modern behavior may have instead "resurfaced" with the advent of agriculture, rather than being there the whole time.

[thecellularrepublic]

This is so well done! Props on the video editing skills and the overall flow and structure of the content. The gut brain stuff at the beginning and the connection that you made to the cnidarians was fascinating. I'm a little biased because its my favorite brain region but I really enjoyed the PFC stuff too. Can't wait to see what else you have coming down the pipeline. Thanks again too for the shoutout for my channel!

[blxnkcxnvas]

Wow, what an absolute gem of a channel I've stumbled upon! This video was both fascinating and comprehensive, yet provides a perfectly detailed overview of the topic. I found it very interesting to consider that our bodies preceded our brains -- it makes sense! I also appreciate the discussion of a more holistic view of the brain, rather than breaking the neocortex away from the more stereotypically primitive parts. I too am guilty of viewing the brain hierarchically, but will try to adopt a more integrated view, as this does seem much more true to life. Thank you for this great video!

[alterI]

really enjoyed this video, Production is great as well as the info and your Host persona is great!

[rzldiqh]

Interesting topic. I like the way you present complex topics in a way that is clear and accessible to a layperson such as myself. Keep up the good work.

[UndulatingOlive]

Great video, is there sketched out tree or flow diagram of the evolution of abilities from single cell to human brain?

For example, ability to absorb nutrients, to ability to move, to ability to control direction, to ability to sense light, this may the wrong order...

Neurologically, is there a map/tree for what changes between eukaryotes to bilateria to vertebrates to tetrapods.... to the human brain?

[idk-hfoi]

Imagine if the gut brain is conscious 😳

[colinadevivero]

Excellent video. Please do not add that horrible background music. It distracts, it doesn’t add value

[richardwestmoreland]

I have heard a theory of how trauma can effect DNA, specifically the DNA described here, that predisposes a person to have a very "reactive" brain leading to anxiety and a propensity for ptsd, as well as neurodivergence and the whole spectrum. So, it's always your DNA that you are passing down, but over time, the trauma you experience can alter which DNA gets copied and to what extent. So your first child could be quite normal, then if you experience quite a bit of trauma, the child you have much later in life would be more likely to have a brain "wired for stress". It's also theorized that in times of great stability, the brains of the population get less and less reactive, while times of great chaos and upheaval produce more offspring wired for stress. I haven't seen any numbers to back this up, but it's an interesting theory.

[pulsar]

I've always believed that morality is based on evolutionary success. The most successful species are those that practice a mix of altruism and selfishness.

[BSPoK]

Your work matters and thank you for the Foundation that is supporting your work!

[mediocrates]

Fantastic! I have sooo much to say, but it's supper time!

Brain function, consciousness, and the implications of qualitative experience have been all I've been thinking about for the last 30some years.

I'll be back!

[lucasnoetzold]

clicked on a random video expecting internet quality content, got actually science backed, source citing content

👏👏👏 keep up