Ecology - Rules for Living on Earth: Crash Course Biology #40

Hank introduces us to ecology - the study of the rules of engagement for all of us earthlings - which seeks to explain why the world looks and acts the way it does. The world is crammed with things, both animate and not, that have been interacting with each other all the time, every day, since life on this planet began, and these interactions depend mostly on just two things... Learn what they are as Crash Course Biology takes its final voyage outside the body and into the entire world.
Can't wait to learn more about ecology? Good news! Crash Course Ecology has 12 episodes you can watch right here:
• Crash Course Ecology P...
Table of Contents
1) Ecological Hierarchy 02:01:2
a) Population 02:12
b) Community 02:26:1
c) Ecosystem 02:50
d) Biome 03:22:1
e) Biosphere 03:51
2) Key Ecological Factors 04:07
a) Temperature 05:06:1
b) Water 05:37
3) Biome Type 06:03:1
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[@lavhayez]

I'm having my last ever biology exam tomorrow before graduating high school so I feel like this would be a good time to thank this channel and Hank Green for essentially teaching me everything I needed to know.

[@daniellayousif3]

Probs not a bio major

[@RORO-be5yc]

Lintang Nawacita How did you do ?!

[@ahfadjaffry2182]

Same im having that tom

[@ahfadjaffry2182]

Eyyy guys my results came i got above 90% so thats max credits :)))

[@SpeedyMcGehee]

Be glad you had this in high school. This whole thing started when I was finishing my junior year of high school. I never studied for my test, but if I had this, my GPA might have been a little higher lol

[@patrickmicho6172]

you make me want to learn more, unlike my school which makes me want to never learn anything ever again. You have reminded me and many other students why science is amazing and interesting. thank you, you are the reason i am doing well in biology

[@bearwithglasses1291]

Who else is here for an online biology class? Cuz quartine and stuff.

[@thesnatcher3616]

no

[@philosophyfulmination8031]

Yes sir and I hate it thanks

[@thaunoi4278]

I just want to share with you guys at Crash Course that I have never taken a Biology course in my life, but by just watching all 40 videos in this series in this last week I took the Biology CLEP test yesterday and passed with a 55. Thanks a load you guys, you helped me complete my natural science credits!

[@Sandlogia]

As a biology student I was fascinated by the way you explain each topic. Thank you Hank for making Crashcourse Biology. Keep up being awesome!

[@sierraweitz5803]

Anyone else here binge watching this in order to prepare for finals

[@mirage2847]

uhhhh that word gives me the chills

[@mirage2847]

+Vanadevana Petrovic. FINALS

[@Hexalogy_]

hiii

[@syd2001]

even a year later people like me are still doing it

[@Niko-yl7nq]

Totallynotsierra same

[@irritableizzy]

studying for biology final... made a playlist that's two hours .... wish me luck

[@Lauren-fx6hn]

Isabel Dabaco good luck!

[@raypunzel4257]

0riginalEscap3r sxuuu

[@jatessaleo2698]

you passed test ?

[@KassIsBoss]

Share the playlist lol

[@jatessaleo2698]

i passed my test!!!!! good luck

[@biancagibbons-morales6277]

Shoutout to the people who just finished watching all 40 videos in one sitting to study for the ap bio test monday!! woot woot

[@Alondrrraaa]

I'm gonna die

[@korryngregory5090]

This is going to be my first AP test and I'm not sure what to expect. X'D

[@Alondrrraaa]

+Korryn Tyndall same for me too, my teacher said it's the hardest test I'll ever take.

[@korryngregory5090]

Alondra Arevalo Yes, for us, too... I do pretty well in my AP bio class (I'm your annoying curve-setter type) but I don't think that's saying much since our AP teacher has been out for a while and half of this semester was taught by a long-term sub, which is... well, it's a thing. I feel quite unprepared. :P

[@biancagibbons-morales6277]

+Korryn Tyndall we will all suffer together!!! yay

[@nevetsjr]

Hank and Crash Course team... thank you for this webseries. My wife is a molecular biologist and this series has allowed me to really talk to her and understand some of her work. Kudos!

[@Sophie-mf1zp]

Crash Course has legitimately saved my life, it includes practically everything in my Biology and Environmental Studies AS Levels!

[@xRainbowInTheNightx]

I have a Clep Examination for Biology tomorrow morning, and I tried studying for it with a couple of text/workbooks I picked up at the bookstore, but I can say that watching the entire crash course for biology really helped me understand the information. I'm nervous for the exam tomorrow, but I can say that I learned a whole lot more from this series than I did when I was trying to teach myself from the books! Thank you so much for this series, and I'll definitely send more people this way if they need help in bio!!

[@lastrachris]

God speed everyone taking the AP Biology test next week, God speed.

[@bildova]

way to go mentioning god twice lol god speed lol tool

[@onomatopoeia9678]

ßildØva Dova God* it is always spelled with a capital G if you are referring to the Christian God.

[@IamMariCS]

I'm taking Biology this year. Thanks to your videos I get to keep up with my teacher's fast paced lessons. Hope you continue to make videos like this.

[@BubblesNKM]

Aw man, I'm about to cry! What a great series, you made me remember how much I love science!! Onwards to more learning!

[@grumpledum]

Thank you so much for this series on Biology. I am currently doing a degree on Biology and your videos though brief, give a very good and accurate overview and summary of various topics! It certainly puts all the little details into perspective!

[@celeluwhen]

Thanks Hank and all the team for this CrashCourse! I just finished watching the whole Ecology course, and it was sooo good to feel my brain cells grow in the process. :)

[@yodadi]

Love it or hate it, it has been a journey for sure, the fact that somone other than a major university can bring us content like this is a testament to the times, this chapter closed and on to the next, I would like to thank you all from the bottom of my heart for this and every past, present, and future series, you are doing good work, and every person should take note of what a small group of people can do if you really put your heart into it, THANK YOU, HANK AND CRASHCOURSE, THANK YOU!!!!!!!!

[@GelidGanef]

Aewsome job on Crashcourse Biology! This and your brother's crash course series are literally my two favorite things on youtube. Looking forward to ecology and whatever else you move into next!

[@tanisaguinsin]

ohhh to be as smart as him. If only.

[@NeonsStyleHD]

Tani Saguinsin Read and Learn and you can be.

[@SonicBluelightz]

Tani Saguinsin actually i don't think hes smart well he might know some i think he has the writers give him paper

[@SonicBluelightz]

Michal Ptáčník dude chill your balls

[@andrewjames2294]

***** very well said my friend.

[@NeonsStyleHD]

He's just reading a prompter lol that someone else has written

[@dorkkis6080]

I am currently studying for my matriculation exams i biology for the second time, and I just want to express how thankful I am for these videos existing. Studying the same things in biology for the second time is incredibly boring, which makes me not pay attention to what I'm reading. These videos provide a fun new way to go through what I've forgotten, and they force me to concentrate since english isn't my first language and I need to understand what he is explaining. I love it!

[@user-pv1kt7qq8d]

"To animate the bag of meat that is you" -Hank Green, Oct. 29, 2019 LOL never thought of it like that

[@davescave7267]

Very good series Hank. Made it a whole lot easier to digest a great deal of information for my course. Thanks.

[@valeriachavezpardo]

You have been my saving grace for biology this year. My teacher is awful and I couldn't understand anything with her, but you have helped me so much! You have the best educational videos on KZbin and without you and John, I wouldn't be doing as well in school as I currently am. Thank you!

[@elizabethmadrigal5972]

I've learned more from watching your videos than I have from my biology professor throughout the whole semester, thank you for explaining everything in terms we can all understand! I feel much better going into my final now :)

[@bleujeanzandcheese]

Not gonna lie - screamed out loud when my Biology teacher showed this to us in class :P

[@sparkynation2899]

Hah yeah my teacher played it to I'm in bio 1b

[@bleujeanzandcheese]

sparkey Kruz I'm doing iGCSE double science.

[@DVMJon]

Thank YOU Hank, although I knew most of this being a vet, I am fully in love with the idea of sharing this wonderfull knowledge of life and its mechanics. And the way you and your brother mediates and teach is captivating and interesting which is perhaps the most important of it all. So thank you so very much. Looking forward to future seassons/lessons

[@amyshepherd6829]

I really like how this Biology series ended with a video on Ecology. It seemed to close one chapter, but then also open another (as Hank was saying). Yet again, Crash Course succeeds in making me one happy (and a little more knowledgeable) viewer! :-)

[@Cubblesnickles]

Took me a couple of months, but I finally finished watching all the episodes. Loved this course, as well as the humor Hank peppers into his videos. Great to laugh while I learn. Thanks for putting this together.

[@tianyixu7853]

Can't believe that I've watched all 40 episodes within 2 days before my AP bio tmr. Hank, thank you so much for your excellent courses...You really save me a lot cuz I was self-studying.I may not achieve a 5 but I'll do as hard as can. I'm sure that I'll continue studying evolutionary biology or paleontology in college. Thanks again for your intriguing crash courses and I will keep up watching them!!! And also, hope that you can upload more biology courses~😉

[@Kai-rp3nb]

徐添翼 wait what u get

[@AngateWier]

Outstanding work by all involved for the entire series. Thank you.

[@zan5051]

Thank you! I had a blast following these videos. Learned a lot of new stuff, got refreshers on stuff I learned in high school. Can't wait for the next series!

[@nenemoko466]

live love Crash Course, keep it up guys! You're all so awesome, thanks for all of the help you provide to so many!

[@mountedczarina9205]

Ecology begins where biology ends.

[@mariebelfond29]

what begins when ecology ends

[@mountedczarina9205]

+Marie Belfond I don't know. Metaphysics?

[@paleorexl5504]

No spaghetti monsters

[@saintcelab3451]

+Marie Belford procreation.

[@rocklobster112]

My booty.

[@benbusa7767]

Eny one else feel like this guy teaches more then our biology teachers

[@thesnatcher3616]

not really.

[@SkywalkerAni]

One of my favorite classes in college was General Ecology. It's such a fascinating subject, and important for finding out about how everything is linked and doing good in the environment.

[@brianadpeterson]

Just binge watched this in two days. Ready for that 5 on the AP Bio exam tomorrow!

[@daddysenpai5638]

hank green your videos are so awesome that my teacher in science even lets the whole class watch your vids in our theater

[@katiemunroe6856]

Jeon JungIDONTGIVEAFOOK wow army really is everywhere huh

[@tylerh4550]

Thanks for all the videos I watch some the night before my biology test, the help it's basically always a recap of my notes.

[@JoelLeBlanc]

Totally excellent course, Hank; many thanks to you and your team. Can't wait for the next!

[@andrewjames2294]

Thank you so much for this you helped so many aspiring students. :)

[@Thomas-xx4fl]

More like PERSPIRING students am i right

[@DeimosAmnesia]

+Thomas Dies I am in an AP class and this pretty much describes my situation perfectly.

[@abbyhetcher6022]

Thanks for the review session! Hopefully this will help me with the AP Bio test tomorrow.

[@Niko-yl7nq]

Abby Hetcher cramming doesn’t always work u should study earlier so you won’t have to cram

[@colinbarnette0]

Thank you so much CC team for continuing forth in leading our quest for knowledge!!!

[@Nerdbraska]

I fangirl squealed when I saw this episode. Hank, you make my life. It took you long enough to get to my favorite sub-topic, but it's worth it! SO WORTH IT!

[@BecomeNika]

I like this video, don't find him annoying...He said everything trough nice and interesting way

[@emeseszorenyi5245]

You guys are the BEST!!!!

[@jessicaabernethy9738]

Thank you crash course! You've helped me more than you'll ever know with my studying. You all are awesome!

[@SilverSack]

Just binged this whole series. Thanks Hank for teaching me Bio when my teacher didnt. Wish me luck on the AP exam!

[@chl4oe]

Thank you for making everything more understandable :)

[@DarkRelm22]

Thank You, Crash Course for helping me on this journey through science....I will re watch these videos....because they were right....Science is Cool. :)

[@grazida0276]

I love crash course so much, I discovered it a few months ago, and i'm in love. THANK YOU ALL SO MUCH!

[@freyalikesbiscuits]

I love it when crash course actually matches up with what I'm learning in school xD it makes it so much easier to understand what my teacher is talking about, and it makes me seem really clever when I watch the crash course of a topic we're about to do and can answer all the questions in class :L

[@elitecoventer4347]

This really helped me thank you

[@NeonsStyleHD]

Thanks heaps for a great series. When are you going to do Physics. Not enough people know enough about it.

[@Qladstone]

NeonsStyle Inspire the next generation of Engineers!

[@B.A.Gondal]

NeonsStyle +1 on that

[@rspace105]

NeonsStyle I agree... A physics Crash Course would be amazing...

[@collinskaranja8990]

+rspace105 check out bozeman science. He does AP Physics, AP Environmental, AP chemistry, and AP Bio.

[@Mixal400]

+NeonsStyle physics course would be great

[@lizizalizard]

I cannot thank you enough for these videos--they have helped me so much, and made me so confident for the AP Bio exam tomorrow. I feel like I have a chance now. Good luck everyone!

[@12301231234]

Thank you Hank! I really enjoyed this series, and I will be looking forward to your next.

[@michaelaller3729]

You should make more biology videos! Please 😁

[@seanbrown532]

Hey, your diagram on deserts forgot the Gobi desert. You know where the uh.. wait for it -the Mongols -live.

[@rachelacuna1885]

taking my last high school bio test tomorrow! huge thank you to everyone involved in making these videos and essentially teaching me everything lol

[@empresssamirah4386]

We love you so much!! You’re an absolute icon, thank you for helping us enjoy learning!

[@Ketzakal]

Hi Crash Course! Your lessons are great! I THINK YOU SHOULD SHOOT SOME VIDEOS ON PHYSICS COURSES! IT WOULD BE INTERESTING AND USEFUL FOR THE COMMUNITY. (EG: YOU CAN BEGIN WITH NEWTON AND KEPLER'S LAWS) TAKE COUNT OF IT PLEASE! THANKS!

[@bildova]

did your caps lock get stuck lol

[@IL0vePcxD]

I've been subscribed for a year but I've never been interested in biology. Now that I have a bio exam next week, I must say that I'm really thankful to your chanel. The content of the video is almost the exact same as what we saw in class!

[@IL0vePcxD]

+ZHOU XUANLE I'm from Canada, doing my 13th grade right now. It's called cegep and it's more or less equivalent to college =3

[@IL0vePcxD]

***** it's going to be my first bio exam of this session. I have two sessions each year and next finals will be in December, the one after December is in June. From your name, I guess you speak Chinese. Sorry if I'm wrong.

[@IL0vePcxD]

+ZHOU XUANLE yess I'm Chinese :D hahahaha. A new "year" starts end August. I happen to live in the French (weird) side of Canada and because of that we have cegep instead of college. It lasts two years, after those years I will be heading to university. It's pretty much the same thing, but with different name. What are you studying right now?

[@gr02mc]

Crash course is the only reason I’m passing biology. My final is tomorrow and this is my way of last-minute studying. Thank you so much!

[@HolyGoucky]

I feel like crying. :'(. This series has been soo good! To the whole team of crash course throughout, good job! :D

[@muniraa5674]

Best teacher ever!

[@sabrinaguibord407]

Hell ya he is! :D

[@sarahwarren9500]

Taking an Ecology test today for AP Bio. Thank you this helped!

[@melodysometimes]

2 years but I'm curious how did it go

[@sajaradi941]

thanks for taking the time to educate people.. I love these videos! I hope you add more biology videos concerning cancer, genetic diseases and biochemistry. Keep up the good work!

[@dewanprotiva6766]

These videos have helped me ever since I was in 8th grade and now I am a sophomore in college. Thanks Hank!

[@chronopolisyt]

me to

[@fonillius]

why nothing about marine biomes? Also there are extra numbers in descriptions quick links to subjects: 3) Biome Type 06:03:1, a) Temperature 05:06:1, b) Community 02:26:1, 1) Ecological Hierarchy 02:01:2

[@Sabrina-ln9ky]

Here I am currently studying for my biology finals this Friday wish me luck I have a B hoping to get into the nursing program.

[@osmia]

Thanks for all the episodes so far. Looking forward to next week. Really hoping next week's Ecology will be on the Oceans!

[@dragsigma]

These videos have helped me throughout the year. Thank you so much Hank my Biology grade would be a sad sight to see without crash course. Also do CC Chemistry!!

[@seanpietrowski5254]

Crash Course Philosophy would be cool.

[@galaxylaurels3539]

Well do I have news for you...

[@lightskinhammer5792]

Sean Pietrowski I’m from the future

[@amandaseltzer7662]

lol who else is using crash course to study for regents instead of using actual notes from class?

[@sarahhock4477]

This is so weird I'm doing the same thing and then I looked at the username and I know you😂😂 this is Sarah btw

[@amandaseltzer7662]

omg😂hey Sarah! I literally fell asleep while trying to study..lol oops

[@AbiesDairies]

me

[@prettylifenai]

How did that go 3 years ago?

[@CyberdustStudios]

Unfortunately for me, Notes. Yes, for a kid who wants to be a future KZbin Gamer, I am using this for studying. I think I'm too young to be dreaming this big. If you count a mid 16 yr. old kid too young.

[@aleclawson7773]

1st video I've seen from crash course and i think I'm now a lifer. Very educational and obviously a good time..thanks guys keep it up!

[@manicpixiedreamgirl7930]

I made it to the end of the course! Watching and trying to understand every video was tough, but worth it! Thank you very much!

[@VioletStar]

Watching it before the exam

[@rubigill378]

Literally watched the whole series in 36 hours because of the AP test Monday....

[@tianyixu7853]

totally the same...AP just after 14 hours due to the time difference...Break a leg!

[@GammaGirlX]

Me too...good luck guys.

[@JorgCAlexander]

Hank & Team, Thanks for being awesome! Excited for Ecology!!!

[@21jhammer]

i have just rediscovered this series and you guys are, still, awesome

[@headmaster0783]

I searched IGCSE biology ecology and I knew CC had something on it

[@shaiwilliams794]

Arigato Gozaimasu :)

[@NinjaTheEwok]

Don't stop making these! They are getting me through my degree, OK slight exaggeration but they are super helpful :) Thanks so much for making them :)

[@misstalentlovesyou]

Crash course, thank you so much for taking your time to make these videos, they make learning more entertaining :D I've learned so much from you guys and I would so much appreciate it if you guys keep on making these these videos :) - someone who can't learn by being lectured by a teacher at school.

[@pensfan2002]

Who else here studying for 2019 AP exam??

[@elricdrick6821]

Hell yeah

[@m.s.9592]

Heck yeah y'all

[@emmyyanchuk3674]

HECK YEAH

[@m.s.9592]

@@emmyyanchuk3674 Just a couple more hours and we'll be freeeeeeee

[@pensfan2002]

Mitra Sutar i hope your one the west coast because you sent this at 3:30 EST you need some sleep my guy

[@mysel2565]

Please make a detailed video about biome

[@milastopforth]

I'll be graduating high school next week and this is probably one of my last crash course videos. Thank you for all you guys have taught me (:

[@MattJammer]

Thank you Crash Course. I am so excited that there will be more stuff to learn about. I will see you again next week

[@kabirawan4229]

2:42 "Living Space" Germans - *casually starts engine to Panzer*

[@jonahpierce2224]

Is crash course biology more like the AP bio course or regular biology?

[@w4yn6]

Thank you... watched the whole biology series and I loved it!

[@revincentiii]

A plethora of valuable information to summarize the last 38 lessons. Thanks!

[@blhfs]

if you slow the video to .5 the speed, he sounds like he's drunk. lol

[@zenyatta5064]

lmao thanks

[@ahmedragai7560]

thx bro lol

[@maturelydisapointingmember2699]

who else was sent here in quarantine?

[@deepagunatilaka6091]

omg i watched all the episodes and i couldn't believe what i was doing at school during the biology period.i think i learnt many things that i didn't understand.this is really useful although its super fast.

[@hecs8850]

Lololol yes

[@SenudaJayathilake]

+deepa gunatilaka are you a teacher?

[@boredomphobia6411]

There were a lot of things I knew but not understood and after this video,like it all connected and I understand it!I immediatly subscribed.

[@AntaresTeam]

Why there isn't a video about viruses?

[@intergalacticsubcultureswe4507]

I mean technically viruses aren't living

[@AntaresTeam]

Intergalactic Subculture Sweets+ I think that viruses become alive when they infect cells

[@intergalacticsubcultureswe4507]

Antares Its not the virus thats alive, its the cell i think

[@AntaresTeam]

Intergalactic Subculture Sweets+ Yes, but the capacity to manipulate a cell is a sign of life. Viruses are at the very edge of life, they can do something only inside a cell, so, this is a quality that give them a place in the group of the living things. They aren't like all of the life form on this planet, maybe they are the missing ring between macromolecules and the simplest life form (bacteria).

[@intergalacticsubcultureswe4507]

Antares true

[@OliviaBohan14]

Why haven't you done anything about Genetics?

[@Nicoder6884]

Watch the 9th through 20th videos of this course

[@alyshaselvarajah8930]

Great video. This is helping me understand ecology for my exams.

[@DerrickDurden]

Loved it, thank you to the whole team!

[@tylersingleton9017]

I have a question that does not really pertain to this episode, but rather biology as a whole. Are there any organisms, or is it theoretically possible for an organism to completely claim and integrate the cells of another organism as it's own. Two things I think would be similar are transplants where a human body accepts the organ if a donar. Or digestion where we break things down to make energy to create structures of our own. However these aren't quite what I had in mind. The reason I ask is i got a great idea for a Sci Fi novel (which of course will include things that aren't necessarily possible). But if this is something that is possible. Is there a name for it, and how would it work? Or can you point me in the right direction for research of my own?

[@MyManThong]

Great question! Yes, actually Human beings are capable of using certain cells from other organisms. A lot of species can use certain cells and structures from other species- however, there are many limitations because of differences in blood type, cellular structure, enzyme functionality, and molecular components. But, it is possible. (The next two things don't answer your question, but I thought, eh, they're cool enough to be worthy of saying) It's also possible for animals to use parts from certain organ systems in other organ systems. Dogs, for example, have had parts of their intestinal tract cut and used them to replace a part of their esophagus (a large portion), and within several days the intestinal-esophagus worked as well as the original, and within a few weeks you couldn't tell the implanted esophagus from the first one. There is a very popular hypothesis in biology that mitochondria, the energy producers of the cell, were once their own separate prokaryotic cell that was 'consumed', per say, in another prokaryotic cell. And this would have to have happened very early on in the history of life because nearly all cells have mitochondria, and the structure of mitochondria seem to indicate an ability to have once survived on their own. So, for sci-fi stuff, there are two more ideas you can use somehow, I'm sure! :D

[@tylersingleton9017]

Broderick Gerano Thank you very much for the reply! I very much appreciate it. It's kinda cool to think that even now I may have cells from other organisms haha. I think that it is very cool that you guys take the time to answer questions even months after the video has been posted. Crash course has inspired me to go back to college and do something I really enjoy rather than working a 9 to 5. You have reminded me how much I love to learn new things and question existing ideas. I'll be signing up for classes next semester. So I thank all of you who are involved in the creation of crash course!

[@MyManThong]

Tyler Singleton I'm currently in school, and it's a great decision! I'm very happy you're getting back into school- whatever you pursue, keep interested, keep learning, and keep showing others how beautiful life is, from math to biology to the human mind to tech. Whatever your passion, good luck, and keep yourself focused. P.S. I'm not a part of Crash Course- I'm just a student who loves biology and wants to help curious people become even more curious, like you, friend. :D

[@DDogg43777]

Yes, it is accepted as fact that eukaryotic cells snagged a bacteria that could make energy really well, and used it for its own purposes. Like a symbiotic relationship. This occurred a LONG time ago. This bacteria is known as mitochondria. It has its own DNA, and during replication, it replicates exactly like a bacteria--using Binary Fission. Hope that was what you were asking!

[@noabsolutelynot3660]

You're writing vore fanfics aren't you.