Introduction to Biology: Crash Course Biology #1 — Transcript

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1. 0:004 billion years ago something very
2. 0:03strange happened on this planet we call
3. 0:05it life and I dare any person any of you
4. 0:09to tell me that it isn't the most
5. 0:11interesting thing that has ever happened
6. 0:13thankfully for all of us it's still
7. 0:15happening it's happening as much if not
8. 0:18more than ever it's squishy slippery and
9. 0:22and slimy and sticky and spiky and
10. 0:25you'll find all the shapes Moss shaped
11. 0:27mosquito shaped manate shaped new shaped
12. 0:30in all the sizes too from Tiny to
13. 0:33tremendous in everything in between and
14. 0:36biology is the study of this thing we
15. 0:39call life we study biology for a whole
16. 0:43bunch of different reasons from the
17. 0:45obvious like making new medicines to the
18. 0:47not so obvious like learning how to
19. 0:49identify
20. 0:50misinformation and we use biology to
21. 0:54describe anything that life does quick
22. 0:57are you breathing right now that is a
23. 1:00biological process life does a lot of
24. 1:03stuff but it's not so easy to pin down
25. 1:05what life is like okay for
26. 1:10sure that ant is alive it responds to
27. 1:14its environment like the crumm it just
28. 1:16found and it must reproduce based on how
29. 1:19many of these ants I see coming right
30. 1:22now but other things respond to their
31. 1:24environment too like if that's our
32. 1:27definition is fire alive is a computer
33. 1:31virus alive is the robot vacuum I call
34. 1:33my personal Butler alive now I'm a bit
35. 1:37biased as a biologist and a living thing
36. 1:40but life is the most interesting thing
37. 1:43to have ever happened on Earth and we
38. 1:46are not even sure what it is hi I'm Dr
39. 1:52Sammy and this is crashcourse biology
40. 1:57wait am I alive but I I am alive right
41. 2:02because we just introduced some serious
42. 2:03uncertainty
43. 2:05[Music]
44. 2:13here life feels like something you know
45. 2:17when you see it but humans have wrestled
46. 2:20with how to define it for centuries like
47. 2:23the ancient Greek philosopher Aristotle
48. 2:25thought the ability to grow reproduce
49. 2:27and react to inner and outer forces set
50. 2:30life apart from
51. 2:33non-life he was off track with some
52. 2:35other observations like he thought that
53. 2:37women have fewer teeth than men and that
54. 2:39eels are made of mud but on the subject
55. 2:41of life he was really on to something
56. 2:44modern day biologists tend to agree that
57. 2:46life involves a state of chemical
58. 2:48balance that reproduces and evolves over
59. 2:51Generations in fact that's also the
60. 2:53definition that Nasa uses should they
61. 2:55ever see signs of such a thing beyond
62. 2:57Earth a self-sustaining chemical system
63. 3:01capable of evolution but for now here on
64. 3:04Earth generations of scientists have
65. 3:06developed a list of seven
66. 3:07characteristics that sort the stones not
67. 3:10alive from the stone fish definitely
68. 3:13alive we know you're there stonefish you
69. 3:16can't trick us no matter how good that
70. 3:17disguise is first living things keep
71. 3:20their inner conditions steady as outer
72. 3:23conditions change and that's called
73. 3:25regulation like on a scorching hot day
74. 3:28when I am ripping sweat and my dog is
75. 3:31panting our bodies are using two
76. 3:34different strategies for the same life-
77. 3:36sustaining goal regulating our
78. 3:38temperature second living things respond
79. 3:41to their environment that includes
80. 3:43Dramatics like when a fast and furious
81. 3:45cheetas Sprints after a gazelle or house
82. 3:48cats imagining that they're cheetah but
83. 3:50they're actually batting at house flies
84. 3:52but it's also the slow motion stuff of
85. 3:54the plant world like the turn of a
86. 3:56flower towards the Sun or a Vine
87. 3:59twisting on a branch third living things
88. 4:03reproduce passing on genetic information
89. 4:05to their offspring and that includes the
90. 4:07bouncing baby giraffe who inherited her
91. 4:09father's eyelashes and her mother's
92. 4:11extra thick tail hair but it also
93. 4:13includes a single celled yeast splitting
94. 4:16in two making more of itself in its own
95. 4:19image oh yeasty the 52nd carrying on the
96. 4:24family name fourth living things also
97. 4:27grow and develop based on the
98. 4:29instruction in their jeans reading those
99. 4:31instructions triggers a tadpole to turn
100. 4:34into a frog or a teenage boy's voice to
101. 4:37change unfortunately jeans can't prevent
102. 4:40those instructions from being read the
103. 4:42day before his solo of Oh Holy Night
104. 4:45terrible timing there when when all in
105. 4:47one night your voice goes from Mariah
106. 4:48Carey to Barry White oh yeah baby it's a
107. 4:54bit of a mess fifth all living things
108. 4:57process energy to do their well living
109. 5:00things like my body is using nutrients
110. 5:03from a Greek salad right now to breathe
111. 5:05pump blood and talk to you and all that
112. 5:08energy was processed by the living
113. 5:10things that supplied my lunch so this
114. 5:12episode of Crash Course is brought to
115. 5:14you in part by a lettuce plant an olive
116. 5:18tree and oddly enough the milk of a
117. 5:20sheep sixth life is organized even in
118. 5:24living things that seem chaotically
119. 5:26arranged to
120. 5:28humanize I'm looking at platypus yeah
121. 5:31even those weirdos have a sense of order
122. 5:34structuring their bodies from the cells
123. 5:35up those groups of cells arranged into
124. 5:38tissues organs and organ systems keep
125. 5:41whole organisms functioning and last on
126. 5:44the list living things have adaptations
127. 5:47shaped by a history of evolution these
128. 5:50adaptations are traits that help
129. 5:52organisms survive and reproduce
130. 5:55individuals that survive and reproduce
131. 5:57pass on their genes and traits ass
132. 5:59associated with them that's how the
133. 6:01Platypus ended up with such a weird cool
134. 6:03body that that includes not just webbed
135. 6:06feet but also venomous Spurs to battle
136. 6:08their Rivals like what are you even
137. 6:11doing with those buddy you have almost
138. 6:14no native predators don't don't you
139. 6:16point those at me wander around with
140. 6:18this checklist of life and you can find
141. 6:21evidence of it in lots of interesting
142. 6:23forms beetles ferns algae yourself your
143. 6:27neighbor I mean please ask first before
144. 6:30looking for that evidence don't don't
145. 6:31spy on your neighbor and at the same
146. 6:33time some of these traits can be found
147. 6:35in non-living things too like take
148. 6:38snowflakes definitely organized but they
149. 6:41don't process energy or think about fire
150. 6:44it grows but it can't reproduce and then
151. 6:48there are some real edge cases the gray
152. 6:50areas where our definition of what's
153. 6:52living and what's not really gets pushed
154. 6:55to the Limit let's head to the thought B
155. 6:57meet the virus a tiny bundle of jeans in
156. 7:01a protein jacket even smaller than a
157. 7:03cell on their own in their little
158. 7:05protein jackets viruses just kind of
159. 7:08hang out they can't reproduce they can't
160. 7:10grow they cannot process energy they
161. 7:13don't even regulate themselves because
162. 7:16nothing's really happening they're like
163. 7:19really complicated dust but when those
164. 7:22jackets Come Off watch out viruses seem
165. 7:26wildly alive their genetic information
166. 7:28replicates they spread between living
167. 7:31things multiplying to infect other cells
168. 7:34and just like cockroaches cactuses and
169. 7:37chimpanzees they evolve over many
170. 7:40generations but there is a catch a virus
171. 7:43can't do any of those things without
172. 7:46first taking over a host cell they can't
173. 7:48take action to infect they have no
174. 7:51system for responding to their
175. 7:52environment they are totally dependent
176. 7:55on bumping into the right cell at the
177. 7:57right time behind every lifelike virus
178. 8:01is a cell that has been commandeered to
179. 8:03do all the work in fact viruses like
180. 8:06rabies direct their host so convincingly
181. 8:09that 19th century scientists thought
182. 8:11that they were among the simplest forms
183. 8:13of life but today most biologists would
184. 8:18say viruses aren't alive and I'd like to
185. 8:20emphasize most instead viruses sit
186. 8:24alongside life in a way they borrow life
187. 8:30and yet we also know that viruses have
188. 8:32been around a long time almost as long
189. 8:35as cells themselves they've evolved to
190. 8:38infect everything from single cell
191. 8:41amoeba to
192. 8:42150 ton blue whales so as life has
193. 8:47evolved viruses have been along for a
194. 8:49lot of the ride thanks th bubble of
195. 8:53course all that said we don't know what
196. 8:55life might look like outside of planet
197. 8:58Earth in fact there's a whole field of
198. 9:01biology called astrobiology devoted to
199. 9:04thinking up what extraterrestrial life
200. 9:06might look like by examining some of the
201. 9:09most extreme forms of life here on Earth
202. 9:12biologists might one day decide to add
203. 9:15to the list or tweak it depending on
204. 9:17what that non-terrestrial life looks
205. 9:19like when it's discovered but for now
206. 9:21our planet is the only one that we know
207. 9:25sustains life ultimately there is still
208. 9:28room for here our qualifications for
209. 9:31life let us draw a circle that keeps
210. 9:33life inside and non-life outside but
211. 9:36don't be surprised if it's the kind of
212. 9:38thing that human thinking continues to
213. 9:40change on especially when and if we get
214. 9:44better at making things that may or may
215. 9:47not be alive debating what does and
216. 9:50doesn't count as life might seem kind of
217. 9:53up in the clouds but hey if we didn't
218. 9:56how else would we know that there are
219. 9:58living micr
220. 9:59up in those clouds that affect the
221. 10:02weather that's right biology is
222. 10:05everywhere is responsible for the
223. 10:08medicine that you take when you get a
224. 10:09headache and for the vaccines that
225. 10:11protect you from serious illness it's in
226. 10:13the cotton of your T-shirt and the Apple
227. 10:15in your lunch both brought to you by
228. 10:18plants that have captured the energy
229. 10:20from the Sun and guess what biology is
230. 10:23in you it's in the organs and cells and
231. 10:26tissues that make everything about you
232. 10:28possible whether that's sneezing or
233. 10:31laughing or digesting lunch writing a
234. 10:33poem or riding a bike and it doesn't end
235. 10:36there no matter what size or shape life
236. 10:39takes every living thing is connected to
237. 10:42every other living thing every bug bat
238. 10:46and bacterium shares a common ancestor a
239. 10:49single- celled organism that lived about
240. 10:51four billion years ago but it's not just
241. 10:54Evolution that connects us the very
242. 10:56molecules that make up our bodies were
243. 10:59born in the heart of a fiery star long
244. 11:02before earth was formed and that same
245. 11:05stard dust will move on after we're gone
246. 11:07to make up new ones in a way you have
247. 11:11just as much claim to the title of
248. 11:13Heavenly Body as Jupiter or Venus this
249. 11:16interconnectedness can be mindblowing
250. 11:19and perspective changing but it's not
251. 11:21just something to Marvel at in the
252. 11:22abstract it's also a practical puzzle
253. 11:25piece that helps us understand ourselves
254. 11:28and our future like
255. 11:30by knowing that we're connected to mice
256. 11:31on the family tree ethically studying
257. 11:34them can help us find cures for human
258. 11:36diseases and because life is connected
259. 11:38by big biological processes we can
260. 11:41understand how our actions affect the
261. 11:43water the land the climate and in turn
262. 11:46Us by showing us life's
263. 11:49interconnectedness biology can help us
264. 11:51and is helping us find solutions to some
265. 11:54of our biggest challenges like hunger
266. 11:57disease and climate change so yeah
267. 12:00biology is everywhere because life is
268. 12:03all around us and by highlighting the
269. 12:07Wild web of connections between you and
270. 12:10every other living thing biology helps
271. 12:12us understand ourselves and each other
272. 12:15and hopefully create a better future for
273. 12:18all kinds of life when biologists and
274. 12:21really people of all kinds ask seemingly
275. 12:24philosophical questions like what is
276. 12:26life and how is everything connected or
277. 12:30practical questions like how do cancer
278. 12:32cells reproduce and what are the effects
279. 12:34of climate change on ecosystems they're
280. 12:37participating in something bigger
281. 12:39something we call the scientific process
282. 12:42but we'll talk more about that next time
283. 12:46this series was produced in
284. 12:47collaboration with hhmi biointeractive
285. 12:50if you're an educator visit
286. 12:52biointeractive.org
287. 12:54g/c crashcourse for classroom resources
288. 12:57and professional development related to
289. 12:59the topics covered in this course thanks
290. 13:01for watching this episode of Crash
291. 13:02Course biology which was made with the
292. 13:04help of all of these nice people if you
293. 13:07want to help keep crash course free for
294. 13:09everyone forever you can join our
295. 13:11community on patreon
296. 13:19[Music]