Evolution and natural selection
Intelligent Design and Evolution The argument that evolution speaks to being the most "intelligent design"
Intelligent Design and Evolution
⇐ Use this menu to view and help create subtitles for this video in many different languages. You'll probably want to hide YouTube's captions if using these subtitles.
- There's been a lot of talk very recently, or definitely
- over the last several years, about the idea of intelligent
- design and how it compares to evolution.
- And my goal in this video isn't to enter into that
- discussion, or it's actually turned into an argument in
- most circles, but really to make my best attempt to kind
- of reconcile the notions.
- So the idea behind intelligent design is really that there
- are some things that we see in our world that are just so
- amazing that it seems hard to believe that it could be the
- product of a set of random processes.
- And the example that tends to be given is the human eye,
- which truly is an awe-inspiring device.
- You can call it an organ or a machine.
- Whatever you want to call it, it does all of
- these amazing things.
- It can focus at different lengths.
- It brings the light into focus at just the right spot, and
- then you have your retinal nerves and you have two eyes
- so can see in stereoscopic vision.
- You can see in colors, and then you can adjust to light
- and dark, so the human eye truly is awe inspiring.
- And the argument tends to go that, look, how can this be
- created from random processes?
- And the goal of this isn't to trace the evolution of the
- eye, but I'll do a little side note here that evolution is--
- and natural selection, and I like the word natural
- selection more because it's not talking
- about an active process.
- Natural selection is acting over eons and eons of time,
- and we do see evidence in our world of a progression of
- different types of eyes.
- In fact, all evidence shows that the human eye is not
- perfect, and that there is variation.
- I mean, we all know some of us are nearsighted, some are
- We have astigmatisms. It degenerates over time.
- People generate cataracts, so there's a whole set of things
- that can go wrong with the human eye.
- I'm not using that as a rebuttal, but I'm just showing
- you that there is variation, even in what I believe is
- truly an amazing piece of biology.
- And even if you go outside of the human world, there's
- obviously a huge spectrum of eyes.
- You have fish at the bottom of the ocean that have eyes that
- are really just light sensors, that barely can maybe tell
- you-- and some insects are like this-- whether there's
- some light or some heat around, nothing
- really more than that.
- And at the other end of the spectrum, far better than
- humans, you have certain birds and a certain type of
- nocturnal creatures where they can see in the dark.
- You know, maybe you have a certain-- actually, all cats
- have this reflective material in their eye that allows them
- much better night vision, so in that way they're superior
- to humans, and they can see just as good as humans during
- the daytime.
- You have certain birds who can see with far more visual
- clarity at far better distances than humans can, so
- there is no perfect eye.
- So I'll go into a little bit of a theological argument
- here, and for those of you who watch my videos, you know that
- I'm one to stray away from theological arguments,
- although I might eventually do a whole philosophy playlist,
- but I want to be very careful not to offend anyone's
- sensibilities, because that truly, truly,
- truly is not my intention.
- But the whole point I want to make is that, look, if you
- believe in a God, and I won't take sides on that argument in
- this video right here, it's to some degree, I would say,
- almost disparaging of an all-powerful being to say that
- this human eye, it kind of gives too much importance to
- us as individuals.
- I always think that religion-- and actually science.
- Or actually everything.
- I mean, we should be humble in our lives, and there should be
- the realization that we, as humans, really-- this isn't
- perfection, and to imply that this is the best that a
- perfect entity or an all-powerful entity could
- produce I think is a little actually disparaging of it.
- I'll give you another example.
- I give you another example, and I'll put my engineering
- hat on here.
- And once again, I want to be very clear.
- My goal isn't in this video to say, oh, you know, look, hey,
- evolution, random processes, that by itself, there is no
- God, and you just have to live with it.
- No, that's not my point.
- I'm actually making the opposite argument, that a
- belief in God would not point to a God who-- a belief in a
- universal, all-powerful God would not point to a God who
- designs the particular, who designs each particular.
- And even more, the imperfections that we see
- around us would-- and especially because we see
- variation and they're being selected for it.
- I mean, we can't just focus on the eye.
- We would have to focus on viruses and cancers, and it
- would have to speak to a God that is designing one off
- every version of every sequence of DNA that we see,
- because if someone talks about designing an eye, we know that
- the eye is the byproduct of DNA, and we know the DNA is a
- sequence of base pairs, you know, ATG, C, A, and, you
- know, billions and billions of them.
- And so when we talk about design, we would be talking
- literally about designing the sequence.
- And we even know that a lot of the sequence, there's some
- noise in there.
- We know that a lot of it comes from primitive viruses deep in
- our past.
- So the argument I'm making here is that in order to give
- credit to the all powerful, at least to my mind, a system
- that comes from very simple and elegant basic ideas like
- natural selection and variations, that in our DNA,
- we call those mutations, in the laws of physics and
- chemistry, and those, from that simple and elegant basic
- ideas, for complexity to emerge.
- So this is one idea and this is what really evolution
- speaks to, that, look, our universe is this profound
- world, this profound environment, where from these
- very basic, simple, beautiful ideas, we have this complexity
- in the structure that is truly,
- truly, truly awe inspiring.
- This is, in my mind, what evolution speaks to.
- And in my mind, even as an engineer, this speaks to a
- higher form of design.
- This speak to a more profound design.
- So this whole video, the whole argument, is that if one does
- believe in a God, and, you know, I'm not going to take
- sides in that in this video, and a God that speaks to
- beauty and elegance and is infinitely powerful, then this
- idea of the laws of physics and chemistry and natural
- selection, which is really-- I mean, you know, when I talked
- about natural selection in the last video, it was really-- I
- think you would find it was a bit of common sense.
- That this is a very profound design and it speaks to the
- art of the designer as opposed to designing each of these
- entities one off.
- And what's even more profound about the design
- is that it's adaptive.
- If there's environmental stress, then the other
- variations survive more frequently.
- And so it's never changing, that perfection, that no
- instance can ever be pointed to and say this is the highest
- point that this design can reach.
- That is always-- I don't want to say getting better.
- It's always getting more suited to its environment as
- it changes, and that to me is a better design.
- Now, just following up on that, and I
- want to be very clear.
- This whole idea is to kind of raise the standard of what we
- expect out of design.
- It's to kind of show other points or other places in the
- scientific or mathematical world where this does emerge.
- And the best example I see of that is with fractals.
- A lot of you-all might have seen-- this is the Mandelbrot
- set, a very famous set of fractals.
- It's immensely complex.
- In fact, you can keep zooming in on the Mandelbrot set at
- any point, and when you zoom it out, it becomes infinitely
- complex, and you can explore it indefinitely.
- But the beauty of it, the true beauty of it, is all of this
- can be described by one equation, one almost
- shockingly simple equation, and that's this: The next z is
- equal to the z before it squared plus 1.
- And you're like you know, Sal, you started talking about
- intelligent design and evolution and all of that.
- Why are you all of a sudden breaking into fractals?
- And the point I'm trying to make here is that if I had two
- designers and one set out to go and paint this exact
- particular fractal and say, oh, you know, I'm going to
- make this brown and I'm going to make this blue and I'm
- going to make this a circle with other circles, you'd
- think this is an amazing painter.
- For example, if you were to go to someone 300 years ago and
- you were to show them this, they would say that this is
- the finest design that anyone might have ever been able to
- devise, because it's so infinitely complex.
- But now we know that this can be completely described by
- this simple equation, literally.
- For those of you are interested, all they're doing,
- this is a complex plane, and they're starting at zero--
- excuse me, not plus 1, plus c.
- Let me make that very clear.
- This is the equation plus c.
- So for every point on the complex plane, you put that
- point in for c, and then you start with zero, and you keep
- doing this.
- So you say zero squared plus that number, that complex
- number, is equal to that.
- Then you put that in here, and then you do that number
- squared plus that complex number, and you do it again.
- You do it over and over and over.
- So turns out that some numbers don't go to infinity and those
- numbers are in black.
- They're considered part of the Mandelbrot set.
- And then the numbers that do go to infinity, as you iterate
- on this formula, you color it based on how fast it goes to
- infinity, and it creates this infinitely beautiful and
- complex pattern.
- Now, if you were to say what is a more profound design, and
- you can ask any engineer this, in my mind, this is the most
- profound design.
- Because it's simple and elegant, but it describes
- something of infinite complexity.
- It's not just focused on the particular, it's focused on
- kind of the metalevel.
- It's focused on creating just the idea of which this is just
- an example.
- So anyway, this is probably my video where I steer most away
- from the science of it all and maybe I focus a little bit
- more on the slightly
- metaphysical or the awe inspiring.
- But my whole point here is to really throw out my little
- idea of how you can reconcile these notions.
- That evolution, the randomness of it, does not speak to a
- Godless universe, although I'm not going to
- take sides on that.
- It speaks to a more profound God, in my mind.
- So anyway, forgive me for taking my liberties, and I
- want to make it very clear, I don't want to offend anyone's
- sensibilities, but I really just wanted to throw
- this idea out there.
- See you in the next video.
Be specific, and indicate a time in the video:
At 5:31, how is the moon large enough to block the sun? Isn't the sun way larger?
Have something that's not a question about this content?
This discussion area is not meant for answering homework questions.
Share a tip
When naming a variable, it is okay to use most letters, but some are reserved, like 'e', which represents the value 2.7831...
Have something that's not a tip or feedback about this content?
This discussion area is not meant for answering homework questions.
Discuss the site
For general discussions about Khan Academy, visit our Reddit discussion page.
Flag inappropriate posts
Here are posts to avoid making. If you do encounter them, flag them for attention from our Guardians.
- disrespectful or offensive
- an advertisement
- low quality
- not about the video topic
- soliciting votes or seeking badges
- a homework question
- a duplicate answer
- repeatedly making the same post
- a tip or feedback in Questions
- a question in Tips & Feedback
- an answer that should be its own question
about the site