Simulating Natural Selection

In this video, we avoid telling the creatures what their survival chances are and let them figure it out themselves. This is the fifth in the series on evolution.

Made with Blender and python.

A few places to learn more about evolution and natural selection:
Any intro biology text you might have access to.

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Creative Commons 4.0 (CC-BY). This basically means you can do whatever you want with this video, but you need to credit Primer and link back to your source. More info at

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The music is “Investigations” by Kevin MacLeod, distributed under a CC-BY license via

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If you're about to leave a comment saying that faster creatures aren't actually less efficient, read this first. I presented that part a bit strangely.

At 2:14, I say moving quickly is less efficient, giving the example of a creature moving a unit distance in half the time, using twice the energy. Then, at 4:53, I show a formula for the energy cost per unit time, which depends on the square of the creature's speed.

I gave distance per time, energy per time, and distance per energy at separate parts of the video, and that was confusing.

So here's a more explicit summary.
If we double a creature's speed…
– its distance per time is doubled (the definition of speed)
– its energy per time is quadrupled (because it depends on the square of speed)
– its distance per energy is halved: (2x distance per time) / (4x energy per unit time)

That last bullet is the "efficiency" from the video. With its starting energy for a day, a 2x-speed creature can only travel half the distance.

I am interested in another variable like temperature.
If you give a creature a trait that it has fur and lets say it lives in an very hot environment like Africa. Why does the fur did not go away from the creature?
Can you run your simulation and see what will happend?

I want to know why animals still have a lot of fure like apes and gorillas and lions and tigers even if they live in a warm environment for a lot of generations

I'm an average person, but in the future all those that survive are the smart ones out there, why do i get the sense that since im average maybe all my future generations will die off?

You seem to have evolution and adaptation confused. A species can adapt to its environment and not necessarily be better than creatures that adapted to a different environment. But evolution is a product of many environmental adaptations and does in fact make a species better/more advanced.

Larger population doesn't mean more efficient than smaller population. The speedy trait aloud for survival of the fittest and so less margin for error hence the population decrease this is a mixture of evolution and natural selection, fascinating stuff this!

When you reduced the food to ten/day you accidently simulated an extinction event and you didn´t even mention it !
The environment changed so fast that, even through your creatures could live on 10 food a day, they had no time to adjust and died out. This is the reason why currently lots of species die out; they just cant evolve new traits as fast as man changes earth.

This made me want to play ARK: Survival evolved, and play with the resource settings and such to see how well I can adapt. I think it could be a fun little experiment

I think the main reason why speed was so important in a Low food environment was because of the time limit set, which meant with lesser food, the time needed to find each food would be more with a lesser speed. This the increase in speed.

Size is flawed. Since creatures can only eat blobs that are 20% smaller, and the blobs all start the same size, none of them are able to eat eachother, so none of them are able to use size as a viable strategy

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