Natural Selection - Crash Course Biology #14
Hank guides us through the process of natural selection, the key mechanism of evolution.
Table of Contents:
1) Natural Selection 1:27
2) Adaptation 2:56
3) Fitness 3:36
4) Four Principals 3:54
a. Variations 4:01
b. Heritability 4:17
c. "The Struggle for Existence" 4:25
d. Survival and Reproductive Rates 5:00
5) Biolography 5:59
6) Modes of Selection 7:40
a. Directional Selection 8:17
b. Stabilizing Selection 8:56
c. Disruptive Selection 9:27
7) Sexual Selection 10:22
8) Artificial Selection 11:24
References:
curiosity.disco...
www.globalchang...
blogs.scientifi...
www.aibs.org/bi...
faculty.clinton...
www.irac-online...
www.pbs.org/wgb...
evolution.berke...
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One way to understand Evolution is to first understand “Artificial Selection”. Wolves and Dogs are descended from common ancestors (which looked more like modern wolfs than dogs). Over many generations, Humans selected the “favourable” traits (e.g., long shiny fur, or stocky legs etc) to produce the many different types / breeds of modern dogs that we have today. The keyword here is “over many generations”. There are modern dogs that, of course, are still very much wolve-like in appearance (e.g., Huskies, German Shepherd etc). Some dog breeds are much less wolf-like in appearance (Chihuahua, Shih Tzu etc) as they have been artificially selected for their small size and “cute” traits. So why is it known as artificial selection? This is because the Human (the dog breeders) are the ones determining which individual dogs they would prefer to produce offsprings, thereby continuing the genes they would like to retain. Prior to this, it is also important to understand the idea of Variation. This means that in a litter of puppies, not every puppy is physically identical (even though they may look identical to the untrained eyes). Some puppies have slightly longer legs, some shorter legs. Very small differences, but, yes, the differences are there. It is due to this physical variations that the breeders (humans) select which dogs possess the traits he wants, thus the term “Artificial Selection”. This Selection process is repeated over many generations and the result is the modern dog breeds we have today. Once we understood Artificial Selection, it will be easy to understand Natural Selection. In Natural Selection, the environment aka Mother Nature (instead of Human) is the factor deciding which traits survive through the generations. How? One example is Food Source. Many species of birds have developed the ability to swim to obtain their food (Adaptability). One pre-requisite of aquatic birds is having water-proof feathers. In this case, this is the “Favourable Trait”. One group of birds may live nearer to the seasides and Individual birds with better waterproof feathers is seen by Mother Nature as a “favourable trait”. And so individual birds with this trait has a much higher chance of survival and passing on this gene to the next generations. Birds with “less waterproof” feathers may probably not even live to adulthood as they had difficulties obtaining their food (in the sea), resulting in their genes being eliminated from this group of birds. Using an analogy, you may think of this process as a kind of filtration process, where only the finest particles is able to pass through the fine filter. This is Adaptation, and it has to be highlighted that Adaptation takes place over many, many, many generations. Physical Adaptations (e.g., change in body shapes) DO NOT take place in just one generation. In other words, an individual animal will not change its form physically to obtain that trait in its lifetime, unless it’s metamorphosis which is a totally different thing. We also observed this in rabbits living in deserts and rabbits living in cold countries. The long ears in rabbits act as effective heat radiators. This enables the rabbits to lose body heat efficiently, just as how humans lose heat efficiently by sweating. The rabbits living in deserts adapted (over many generations) to the environment by developing very long and erect ears for highly efficient lowering of their body temperature. But rabbits living in cold countries tends to have shorter ears (some even have lop ears). Shorter ears is the “favourable trait” here as it enables them to lose less body heat. All animals (and yes, that includes Humans) are still in the midst of Evolution. If Evolution is constantly ongoing, why can’t we see it happening? We need to understand that Evolution is a very, very slow on-going process. Evolution will never be “complete”, as change is the only constant. If Evolution is true, why are there no animals that are “neither here nor there” (i.e., in-between two species)? We need to remember humans are the ones who gave distinct names to different distinct species of animals in the first place. Let us look at the Seals / Walruses. Their ancestors are land animals, but their body shapes (flippers and hydrodynamic bodies) are hard evidence that they are in the midst of “transition” from land animals to aquatic animals, as their main source of food is in the sea. Of course, we cannot see an appreciable change in their appearances in our lifetime, as the change is happening far too slowly over many generations. So presently, we can only imagine the current physical appearances of Seals / Walruses as being “frozen-in-time”, as with the rest of the millions of species of animals currently living on this planet Earth. And do appreciate their beauty in their current physical form (and the diversity of the Tree of Life), as they will never be the same again one million years from now.
4:39 " This leads to what Darwin called 'the struggle for existence' " Did you mean: my life
@vampyricon7026
7 жыл бұрын
+
@thatonemajin3578
7 жыл бұрын
-
@jenbinchin5897
7 жыл бұрын
TRue
@jade02824
6 жыл бұрын
same
@ananyadutta1189
6 жыл бұрын
schmood
Anyone Binge-watching the bio videos the day before your exam?
@cleopatrak8792
8 жыл бұрын
+Kloud Chulikavit me
@sotantarsinghkhalsa7934
8 жыл бұрын
me
@keosika.7964
8 жыл бұрын
haha Im watching them the same morning as my biology AS exam 😂
@zaidqolaghasi2475
8 жыл бұрын
+Truewildspirit There's no natural selection in Unit 1!
@keosika.7964
8 жыл бұрын
+Zak Zoka I do Aqa and anything could be on either of the exams
So we can all agree that youtube teaches better than school? Only 2 weeks I've been studying here, and I already learned almost half a semester of this year.
Study? No I'm gonna watch crash course videos and hope for the best!
@eerieberry3902
8 жыл бұрын
+sasha paul this is what i have been doing whole day knowing the fact that i got an exam tomorrow.
@kilic_
8 жыл бұрын
+Salwa Chy How did it go?
@MrJamesfalco
7 жыл бұрын
sasha paul sadly he failed.Fact for the reason he never responded.
@michelleechenique6592
6 жыл бұрын
How did that go?
Could you have a test at the end of videos as an option maybe? would help people study better. Just as an option
@freakypeep727
6 жыл бұрын
www.khanacademy.org/science/biology/her/evolution-and-natural-selection/e/natural-selection-and-darwin
@Starkiller475
6 жыл бұрын
KB Miller ya
@valawee
5 жыл бұрын
NotYourAverageJesusFreak it's not possible to get an 80% on that test, you probably got a 75%
@maatoukboss2374
5 жыл бұрын
Easy Hundo, lets goooo baby @@freakypeep727
@GabijaS18
5 жыл бұрын
I got 100% it was literally common sense
nobody: him: I'm human but let's just pretend i'm a m o t h
why dont colleges just send you to this channel and save us hours of useless lectures
@brandon2932
8 жыл бұрын
Seriously i think some college classes should just be at home without instructors. I always learn much more from the textbook or through youtube videos. Not necessarily because they're bad teachers, but I just learn better that way instead of hearing someone lecture.
@katavia4131
8 жыл бұрын
brandon2932 same here idk what it about that but sometimes i would rather just learn it on my own
@spinct83
8 жыл бұрын
because that wouldn't make them any money.
@dwightschrute8567
7 жыл бұрын
spinct83 Truer words have never been spoken.
@minerjoe5538
6 жыл бұрын
ive just been given this video as a homework so nice
Who else is cramming for a bio final or sat
@nessab.7519
8 жыл бұрын
Basically yeah
@mimie0155
8 жыл бұрын
here here tomorrow
@maxwellrux5523
7 жыл бұрын
yup goodluck
@aidana3761
7 жыл бұрын
julianna weil 👋👋
@photolover820
7 жыл бұрын
julianna weil AP test so kind of yes
I have to say, after finding this chanel I've been able to understand my biology class a lot better. This channel is very helpful.
I KNEW IT I KNEW THAT YOU'D BRING UP THE PEPPERED MOTHS
@lachlantaylor1225
9 жыл бұрын
EyeOfTheLauren and Daphnia come up in our course too! although for Caffeine stimulation
@ArtsyChick24
9 жыл бұрын
#IBbiology
@sakurasaya
8 жыл бұрын
+EyeOfTheLauren Haha same here!! :D Got a test tomorrow...._.
@verstalgaming9685
8 жыл бұрын
+EyeOfTheLauren ayyyyyyyyyy IB
@samaa4247
7 жыл бұрын
Me too
The explanation in the first minute almost exactly explains why humans evolved in Africa to have dark brown/black skin and why less pigmented humans went else where. The less pigmented humans where harassed and eaten by birds because they were more visible to the birds, and the darker humans where not as easily seen.
@satnbert
10 жыл бұрын
Feed the troolll!!
@The10thManRules
10 жыл бұрын
***** sorry, my joke was apparently, not apparent.
@nmarbletoe8210
9 жыл бұрын
RETiredGM i got it, industrial melanism. but moth of your facts are wrong
@trotcodg
7 жыл бұрын
its true though its just their skin evolved by how it affects the sun for example, pale blonde hair absorbs more vitamin c
@fallen_herosigma3494
5 жыл бұрын
@@nmarbletoe8210 im moth so i must like lamp
You saved me I have such a better understanding about this unit. I wish you were my biology teacher.
This is one of the only reasons why i am passing Biology!!!! Thank you soooooo much
I swear, this dude never blinks????
@googelplussucksys5889
9 жыл бұрын
He has glasses so he probably doesn't need to blink...
@lukesobolewski710
9 жыл бұрын
Maybe at 1:11??
@CanyonF
9 жыл бұрын
Maybe he just has extra moist eyes so he doesn't need to?
@claudineallen5732
9 жыл бұрын
He blinks at the end when he talks about the dogs lol
@MasterPoppers
8 жыл бұрын
+Googelplus Sucksys Do... you know how eyes function?
Thank you, thank you, thank you, thank you, thank you. I just started Biology and I'm feeling overwhelmed. My notes + your crash courses make it all sink in! I may stand a chance!
I can't believe that the video released 8 years ago 👀
You guys are saving my English major butt from failing my one Bio class... THANK YOU!!!
Thank you for your videos. I wish all my science teacher were like you :)
Who is watching this because your Biology teacher forced you to do it? 🙋🏼♀️
@bruhenthusiast3048
4 жыл бұрын
Lets goooo
@gengushmurda6448
4 жыл бұрын
1 week ago, and I’m just now doing it
@nathanmckenzie904
4 жыл бұрын
You should thank your teacher
@captainnihilo
4 жыл бұрын
Up top
@gabriellaortiz4075
4 жыл бұрын
I have to write down 10 things I learned from this video🙄
This is all wrong The answer to life the universe and everything is 42
@TheatreDork87
10 жыл бұрын
Truth.
@zemorph42
10 жыл бұрын
Ah, but the important part is the question.
@KennethColeman426
9 жыл бұрын
HA HA He's right 42 is the answer I saw it on my Video The Hitchhiker's Guide to the Galaxy YAY! *I LOVE THAT VID. I have it on VCR cassette tape(;)
@robh9165
9 жыл бұрын
M = 13 A = 1 T = 20 H = 8 13 + 1 + 20 + 8 = 42 Conclusion = maths is the meaning of life
@buclao643
9 жыл бұрын
please have 42 likes!!!!!!!!!!!
"The Hungry Birds of London" is a GREAT band name
you save my ass every time i have a biology exam. thanks buddy.
Pshhh. I hate it when people put comments that are not related to the video. Evolution does not explain how the world is first created. If you want to ask questions about theories on how the world began, then watch a video of how the universe is developed, and not a video about natural selection
@MasterPoppers
8 жыл бұрын
+0xJamica0x It's not so much natural selection that is the problem with creationists, it is more so mutations, as natural selection does not create any variation in the DNA, but only selects based on what is available. Mutations on the other hand, are what cause the variation from species to species (for the most part).
What is the point on spending $5,000 per semester in college, just to have my professors make me watch this hooligan on KZread WHICH I COULD HAVE DONE FOR FREE. What an absolute rip off.
Anyone else have a bio final coming up? Mine is tomorrow. And just like a few (or most) of you, I've waited until last minute.
@Mark-ht1ed
8 жыл бұрын
Kkjjj
@sophiecloutier8569
7 жыл бұрын
THATS ME RIGHT NOW AND ITS 4AM AND I STILL HAVENT SLEPT
@metalgarbage3121
6 жыл бұрын
LMAO BIG MOOD TOMORROW 12/19/17 😩
Kid: dad what does stove do *goes to touch* Dad: Don't you- Dad: *sigh* natural selection.
@atticusyoungs6
7 жыл бұрын
Ya Boi #parentoftheyear
@quitschi9954
6 жыл бұрын
Tbh, I think this is more of an example of a that is irrelevant to natural selection. If a preference to touch stoves would be detrimental to reproduction, it would be selected against and kids touching stoves would be a rare occurence. Wouldn't it?
@ChalkLitIScream
6 жыл бұрын
Quitschi especially if the dad knows not to to touch it, it should (loosely should) be hardwired in the kid too. This would be more learning, which is change within a lifetime
@Diamondraw4Real
5 жыл бұрын
@@ChalkLitIScream but the kid is a kid, probably dad was dumb when he was little too. He only learned after touching the stove. Teaching as much as learning... I guess.
@nukkazade6399
5 жыл бұрын
why.... why......@@Diamondraw4Real
"So thanks to the soot-covered everything, I've got problems." lolololol
I do online school and basically skip the lessons and go straight to the assessments. I literally just learned 6 lessons worth of Biology in this video 😂😂😂😂
Thank you for all these biology videos! Best study tool ever
I always watch a crash course before every test for my AP Biology class. Helps me remember what I've learned. I'm not very good at studying so visuals always help.
I'm gonna binge Hank's videos for my semester exam tomorrow. Luckily he has a video on everything I need to know, evolution, classification, and human systems. Yay!
I learned more in a day, than I did with my teacher for 1 year
Thank you! This is how I study for my tests!!! ❤️👍😄😂
I home school my 2 teenage kids and these crash course videos help out so much. Thank You!!
This blog is very informative and useful especially to those people who are engaged in Agricultural Industry. Being able to give the advantages and disadvantages of the said topic is good. With that, readers can think wisely whether to engage to Artificial Selection or not. Also, clipping many pictures makes it appealing to read and easy to understand. In the end, I learned that Artificial Selection is important in terms that people will benefit from it through lots of agricultural produce but should be wise enough because it can affects the economy, environment and God’s plan of creation.
these would be excellent to have in a podcast and I'm sure you'd get a huge audience !
Thank you I've been cramming for the last three days and this video helped the most
I'd actually argue that peacock tails would be a great example of stabilizing selection. They need a big enough tail to attract the ladies, but not so huge that they can't move to find food or escape predators before they've had a chance to pass on their genes. Thoughts? Love this channel : ) -BOGO
This is a very good presentation of the facts. Thank you CrashCourse.
10:48 - so that's why gingers, nerds and shy guys have such a hard time at school. Thank you, Darwin!
@xboxboy93941
9 жыл бұрын
Marcin Pasternacki You had Shy Guys at your school? Were there any Goombas?
@pokeniners6009
8 жыл бұрын
+Marcin Pasternacki HAHAHAHA TRUUUU I am 5"4 and every freshman in my high school is about 5"10-6"3 (I am talking about males and I am a male). It is very difficult!!
@mokiberri3053
8 жыл бұрын
+Tricell CEO looool references
@ChelCoh
5 жыл бұрын
Marcin Pasternacki your profile picture goes with your comment
it's 2019 already and I always used this if I have an exam in Biology :)
my science teacher shows us these in class and she always talks over the video so I just gave up on trying to hear him and I'm watching this on my own time at home.
I've learned more in an hour of watching Hank's videos than in a month of actual Bio class. Thanks for the videos. :)
i think this is my favourite crash course biology!! It was interesting and easy to follow. Soooo much less complex than previous videos :)
Thumbs up if your Biology teacher forced you to watch this!
@dilleraimer
9 жыл бұрын
I wish my biology teacher did stuff like this
@keira_churchill
9 жыл бұрын
Oh no! Teachers educating kids. How evil of them. Whatever next?
@keira_churchill
9 жыл бұрын
Edge you katon is over eated.
@frosty_1000
9 жыл бұрын
Thumbs up if you came on your own cause you actually like science!
@arcticheroh
5 жыл бұрын
@@frosty_1000 I originally came to understand meiosis a little better, but now I'm on this video which is just from curiosity. I am starting to like biology more and more.
Natural selection is one of the mechanisms of evolution. It describes how advantageous mutations ("differences") provide better chances of resource allocation ("survival") and therefore allow for more opportunities for reproduction. Evolution is not only supported by literally mountains of evidence, it is also not refuted by any evidence, and by our current understanding (which is considerable), it is inevitable in all type of conceivable life (that reproduces and competes for resources).
You can turn the closed caption on at the bottom of the video on the right side. I live in the city and it is often loud outside my windows, so I usually read along with Hank. Hope this helps!
Great strategy: be cute so humans take care of you!
Is anyone else here out of pure interest and not for an exam?
@ismellrudolph
7 жыл бұрын
Me, I got sacked from work so I´m trying to get as smart as possible before my mum kicks me out of the house
@ismellrudolph
7 жыл бұрын
Hopefully if I get smart enough I can find a mate to pass my genes on then die in a ditch
@teyat798
7 жыл бұрын
nope
@squidwardswift
7 жыл бұрын
ismellrudolph damn
@leticiahuertauribe37
7 жыл бұрын
catrina g I'm here cause I need to improve my english :3
I'm using these for finals, and I think my bio class is fantastic. There is just something really helpful about being able to call up another version of the lesson on demand, start it, stop it, and review whatever I don't get for hours! I asked my prof if she'd be down for this, but she said she had something else to do...
watching this 10 minutes before my zoom meeting where i have to present what i learned from this video.
You forgot to mention Alfred Russel Wallace
@adelajaini5019
6 жыл бұрын
Thomas Haynes Poor Wallace. Forgotten by history and future scientists.
Thank you for the wonderful video😊 I've learned a lot from this video i knew that this kind of selection is the process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype constitution.
comments 2010: oh cool video! comments 2020: 90% MEMES
anyone else being forced to watch this during coronacation?
exams today...... Thank god for these videos
For people who don't get it here is the difference between macro and micro evolution. Macro Evolution allows for slight variation that will help shape a distinct feature in the future but is not easily noticable yet. The only difference between the two is time. Longer periods of time causes an accumulation of these changes wich causes the earlier mentioned distinct features this is called micro evolution. Given enough time there is even species creation, because of a significant change in DNA.
@nmarbletoe8210
9 жыл бұрын
***** God made evolution happen. Not to call it bullying, but i'm going ot let the Almighty have his way on this one.
@stephaniemitchell8509
9 жыл бұрын
***** This is BS. High School Biology classes spend ONE week on ONE chapter on evolution, then moves on. I had to go outside of school to research it in further depth, as our childhoods are spent indoctrinated into our parents religion, and we're effectively sheltered from the facts and truths that science sheds light on. You should lay blame on indoctrination where blame is due, within the archaic, science-denying lies of religious myth that had people believing the earth was flat and Antarctica penguins tottled all the way from their frigid habitats to the desert climate of Noah. You're fucking insane.
@melissasandejas5036
9 жыл бұрын
You switched the two. Macro is the longer one :)
@melissasandejas5036
9 жыл бұрын
You switched the two. Macro is the longer one :)
@uzziya6392
9 жыл бұрын
+Why not realisitc Zoidberg? That's not strictly true. The distinction is strange, but in most cases macro-evolution is just speciation. It requires more than time in most cases. If two populations interbreed then they're the same species and will remain the same species because this interbreeding prevents them from diversifying on their own. For "macro-evolution" two populations must become separated, either by time (as you said) or by space, the latter being far easier to observe. Once separated the two populations can diversify independently and eventually be unable to interbreed once reintroduced but it's not possible to do *unless* you have that initial separation.
Because its the beauty of evolution caught and recorded! its fantastic.
This video contained more visually explained examples than your other videos, which made me understand the concepts better. So I would suggest using more of those.
I think I have a crush on Hank
All of these comments are from 3+ years ago I just got sent here for school 🤦🏽♀️🌝
I love how i'm watching this in my free time during the summer :)
Today, we talked about that very example with the peppered moths in class to introduce Natural Selection. I was like: "Yeah, so I think the black ones were more common after a while because, you know, the industrial revolution turned the birch trees, their habitat, dark and thus, the black ones survived more easily."
ALFRED RUSSEL WALLACE! Never Forget
@lailaden7061
8 жыл бұрын
Right?!? Everyone leaves him out.
@4EverMarup
8 жыл бұрын
+Olivia G and herbert spencer
@crystinamarie1
8 жыл бұрын
I was just thinking that. He says Charles Darwin was the first? Eh! Wrong.
I'm here cause my country is completely ignoring a disease and all social with eachother spreading it atm.
your point that individuals dont evolve, but evolve their species was beautifully put
i wish we had these channels when i was growing up, would've aced the exams
Thank you hank so much this helped so much as I go to a Christian school so we only talk about how natural selection is wrong
@samantha3929
6 жыл бұрын
smbatman123 that’s really sad
@IsaacNussbaum
5 жыл бұрын
*"...only talk about how natural selection is wrong:* It is, smbatman123. It is. _“We have both spent effort and ink… to show that Darwin’s theory of natural selection is fatally flawed.”_ _“We think this argument_ [natural selection] _although ubiquitous in the literature, is fallacious.”_ ~Jerry Fodor and Massimo Piattelli-Palmarini
@saitui4614
5 жыл бұрын
@@IsaacNussbaum please continue...
@melylamash
5 жыл бұрын
I also go to a Christian school, I'm taught that natural selection is NOT equal to evolution 1.) Because no new creatures were created, even within population shifts. 2.) Most mutations are harmful and do not help the creature 3.) It's just nature taking care of itself
@smartave5882
5 жыл бұрын
@@melylamash Im creationist its sad seeing this many people not even beliving God created each and every one of them :( :( :(
Do you guys have a video about cellular evolution?
This blog shows how people reacts to all living things in the earth. Thats why there is events that species change depends in the environment and the weather. This blog is helpful for those who are finding pets that is friendly, and we can know when the food is safe or it has poison or it has a bad effect on our body
Tower Bridge was built 1886-1894. But your decision to use it to illustrate early 1800's London doesn't disappoint me.
Mr.olsen if you can see this, I’m falling asleep watching the videos your making us watch 😡
@Ella-db9ge
4 жыл бұрын
You can download the transcript and just read it
this is one of few channels on KZread where the comments section is quite intellectual, whereas other channels have twelve year olds fighting with eachother
So, you just summed the first six chapters of my physical anthropology textbook in 12 minuets. This is amazing!
thank you for making this video to help me understand this for my biology class
R.I.P Lemon
Do creationists always try to argue with people in the KZread comment section?
@TruckerPhilosophy
8 жыл бұрын
+crue woe They don't have anywhere else to go.
@leeking3697
8 жыл бұрын
+crue woe Usually Creationist say something stupid, then an Atheist calls them stupid, then another Atheist calls that Atheist stupid, and so on and so on till you have a flamewar
@Knackyj
7 жыл бұрын
lol, so true although it often gets started by atheists, and a creationist calls the atheist stupid, and then another creationist calls that creationist stupid, etc.
@mymusicplaylist6889
6 жыл бұрын
Alec Reilly I don't see anyone even arguing lmao
@smartave5882
5 жыл бұрын
im creatiion ist
love love LOVE UR VIDEOS, I LEARN SOO MUCH FROM THEM....thank u sooo much
That's because it's such a perfect demonstration of the process.
Bad genes will eventually die off, and only the best/most desired genes will survive.
your face on that moth😂
I can't begin to say how happy I was when I found out this was a video for our high school biology class.
This video taught me more than my teacher in a week
Who’s watching this during home school because of quarantine
Anyone watching this to revise for their exams
You look more natural and fitted out side the studio. Thanks to the selection of your natural characters.
THIS VIDEO omgoodness, thankyou this has been a lifesaver, i had to take a biology test first day of school and you just summed up EVERYTHING in the theme evolution that i had to learn, love love love it :'D
Makes me sad that Darwin gets all the credit
@anungodlyamountofcereal6384
6 жыл бұрын
Lily Griffin well,Alfred agreed to let Darwin be the main spokesman for evolution and get most of the credit because Darwin had gathered much more proof
@smartave5882
5 жыл бұрын
Darwin said it was just a theory he never said it was a sure fact
@angryoldcanadian3905
4 жыл бұрын
@@smartave5882 another person who doesn't understand what 'theory' means in a scientific context.
@smartave5882
4 жыл бұрын
@@angryoldcanadian3905 Yeah. An educated guess. Not a fact. Evolution can't and never will be proven. Edit: I just looked it up and it says a theory is a reliable account. Basically an educated guess.
@angryoldcanadian3905
4 жыл бұрын
@@smartave5882 False A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment. Evolution is a FACT. An educated guess is called a Hypothesis. Evolution is proven more than gravity... which is also a theory AND a fact. This is the problem with those who lack a scientific education. To say that evolution is not a fact shows your ignorance, nothing more
He does not blink because it is made of lots of little videos.
Next one on mitochondrial Eve please, as a lot of people misunderstand the concept! The world needs you guys :)
Studying for my bio exam!! this helps so much
1:15 Turn on Captions
Does anyone else take notes while watching these videos?
@ornellamaxwell3581
8 жыл бұрын
+canonme1 yes, I think it helps to build nice coherent notes. A good summary of large book chapters of same topics
@mohidkhan9819
6 жыл бұрын
canonme1 I do all the time even if I don't have an exam or its above my grade level
@davidboutros7022
6 жыл бұрын
I do to because it is a lot easer then when a teacher is explaining a lot of things so I. think its good to take nots on this video Evan tho Im forced to to get a good grade by way teachers.
I find myself rewatching these constantly before my bio exam
There is an oversight in the peppered moth study. They were placed on trees by researchers instead of being allowed to find their own placement. But it's still a good example of the mechanisms of natural selection.
@R3tr0v1ru5
8 жыл бұрын
Natural Selection is a mechanism.
4:44 Looks like hank predicted 2020.
@CrypticXX525
4 жыл бұрын
Yeah but that wasn’t because of overpopulation
Its highlarious how many religious people are freaking out in the comments xD
@justincadieux1535
6 жыл бұрын
Rallen jesus is with you
Helping me pass higher Biology :) Thankyou!
im so tired, hank's bad jokes are actually funny