The History of Life on Earth - Crash Course Ecology #1
video description
Date: 2022-04-04
Related videos
Comments and reviews: 6
Taylor
The History of Life on Earth - Crash Course Ecology #1 NOTES-
1: Course Intro-
1. 1: Biology knowledge is assumed-
1. 2: Everything connects back to ecology-
1. 3: The history of life here eventually leads to humans, the most important species on Earth-
2: Before Life on Earth-
2. 1: Humans are currently the dominant species on the planet, with different dominant species over time-
2. 2: Most of Earth-s history from its creation 4. 6 billion years ago was devoid of life due to excessive heat, much of which remains in Earth-s core-
2. 2. 1: Earth-s core continues to influence geology, albeit slowly-
2. 3: Water eventually cooled enough to turn into liquid-
3: Start of Life on Earth-
3. 1: A -soup of chemicals- such as nitrogen, methane, and hydrogen formed in the oceans and atmosphere-
3. 1. 1: Life started as these chemicals formed organic molecules, most likely just a collection of chemicals surrounding a membrane, called Protobionts-
3. 2: These chemicals turned into amino acids and, eventually, RNA-
3. 3: Protobionts continued to split until DNA nucleotides formed, leading to single-celled organisms-
4: Single-Celled Organisms-
4. 1: The first single-celled organisms were prokaryotes during the Archaean Eon, from around 3. 5-2. 1 billion years ago-
4. 2: A type of prokaryote called cyanobacteria began to make its own food through photosynthesis, releasing oxygen into the atmosphere and opening the way for oxygen-breathing organisms-
4. 3: Eukaryotes evolved by endosymbiosis, where a symbiotic relationship between two prokaryotes led to the development of organelles such as mitochondria and plastids, allowing for much more complexity-
5: Multicellular Organisms-
5. 1: The first multicellular organisms formed around 1. 5 billion years ago, first as algae-
5. 2: The Cambrian Explosion 535 million years ago led to an evolutionary arms race as species known as Chordates developed skeletons, shells, claws, etc, resulting in the dawn of the Phanerozoic era-
5. 3: Around 500 million years ago, species left the oceans and colonized land in the Ordovician Period-
6: The First Land-Based Species-
6. 1: 365 million years ago, tetrapods (essentially fish with legs at the time) and arthropods (spiders and insects) appeared in the Devonian period-
6. 2: Land-Based organisms changed ecosystems as they expelled carbon dioxide after inhaling oxygen, leading to the Carboniferous period around 359-299 million years ago where dense forests sprouted up-
6. 3: There was too much oxygen, leading to global cooling and the destruction and eventual fossilization of these forests, which are used in today-s fossil fuels-
7: Pangea and the Dinosaurs-
7. 1: Around 299-251 million years ago, Pangea formed as one large continent during the Permian period, altering ocean currents and the climate-
7. 2: Modern ferns and pines, as well as archosaurs, showed up as a result of these geological changes-
7. 3: The Permian-Triassic Extinction Event resulted in the vast majority of species going extinct-
7. 3. 1: Dinosaurs evolved during the Triassic as there was little competition for their niche from other species-
7. 4: During the Jurassic and Cretaceous periods from 199-65 million years ago, more complex dinosaurs evolved as herbivores, carnivores, and massive sea-going species, as well as small mammals, roamed the Earth-
7. 5: Around 65 million years ago, a major extinction event occurred where most dinosaurs, with the exception of birds, went extinct-
7. 5. 1: The event was likely caused by an asteroid, but may have been caused by climate change-
7. 5. 2: Another theory is that dinosaurs often refused to eat angiosperms, a type of plant that evolved around 100 million years ago, which became more common-
8: Modern Life-
8. 1: Mammals and birds dominated the world after the extinction event-
8. 2: Despite continued climate fluctuations and extinction events, species continued to evolve into what we know today, including humans-
8. 3: Ecology provides us with the best guesses of what will happen
reply
The History of Life on Earth - Crash Course Ecology #1 NOTES-
1: Course Intro-
1. 1: Biology knowledge is assumed-
1. 2: Everything connects back to ecology-
1. 3: The history of life here eventually leads to humans, the most important species on Earth-
2: Before Life on Earth-
2. 1: Humans are currently the dominant species on the planet, with different dominant species over time-
2. 2: Most of Earth-s history from its creation 4. 6 billion years ago was devoid of life due to excessive heat, much of which remains in Earth-s core-
2. 2. 1: Earth-s core continues to influence geology, albeit slowly-
2. 3: Water eventually cooled enough to turn into liquid-
3: Start of Life on Earth-
3. 1: A -soup of chemicals- such as nitrogen, methane, and hydrogen formed in the oceans and atmosphere-
3. 1. 1: Life started as these chemicals formed organic molecules, most likely just a collection of chemicals surrounding a membrane, called Protobionts-
3. 2: These chemicals turned into amino acids and, eventually, RNA-
3. 3: Protobionts continued to split until DNA nucleotides formed, leading to single-celled organisms-
4: Single-Celled Organisms-
4. 1: The first single-celled organisms were prokaryotes during the Archaean Eon, from around 3. 5-2. 1 billion years ago-
4. 2: A type of prokaryote called cyanobacteria began to make its own food through photosynthesis, releasing oxygen into the atmosphere and opening the way for oxygen-breathing organisms-
4. 3: Eukaryotes evolved by endosymbiosis, where a symbiotic relationship between two prokaryotes led to the development of organelles such as mitochondria and plastids, allowing for much more complexity-
5: Multicellular Organisms-
5. 1: The first multicellular organisms formed around 1. 5 billion years ago, first as algae-
5. 2: The Cambrian Explosion 535 million years ago led to an evolutionary arms race as species known as Chordates developed skeletons, shells, claws, etc, resulting in the dawn of the Phanerozoic era-
5. 3: Around 500 million years ago, species left the oceans and colonized land in the Ordovician Period-
6: The First Land-Based Species-
6. 1: 365 million years ago, tetrapods (essentially fish with legs at the time) and arthropods (spiders and insects) appeared in the Devonian period-
6. 2: Land-Based organisms changed ecosystems as they expelled carbon dioxide after inhaling oxygen, leading to the Carboniferous period around 359-299 million years ago where dense forests sprouted up-
6. 3: There was too much oxygen, leading to global cooling and the destruction and eventual fossilization of these forests, which are used in today-s fossil fuels-
7: Pangea and the Dinosaurs-
7. 1: Around 299-251 million years ago, Pangea formed as one large continent during the Permian period, altering ocean currents and the climate-
7. 2: Modern ferns and pines, as well as archosaurs, showed up as a result of these geological changes-
7. 3: The Permian-Triassic Extinction Event resulted in the vast majority of species going extinct-
7. 3. 1: Dinosaurs evolved during the Triassic as there was little competition for their niche from other species-
7. 4: During the Jurassic and Cretaceous periods from 199-65 million years ago, more complex dinosaurs evolved as herbivores, carnivores, and massive sea-going species, as well as small mammals, roamed the Earth-
7. 5: Around 65 million years ago, a major extinction event occurred where most dinosaurs, with the exception of birds, went extinct-
7. 5. 1: The event was likely caused by an asteroid, but may have been caused by climate change-
7. 5. 2: Another theory is that dinosaurs often refused to eat angiosperms, a type of plant that evolved around 100 million years ago, which became more common-
8: Modern Life-
8. 1: Mammals and birds dominated the world after the extinction event-
8. 2: Despite continued climate fluctuations and extinction events, species continued to evolve into what we know today, including humans-
8. 3: Ecology provides us with the best guesses of what will happen
reply
Fernando
Thank you I watched after taking my ecology exam 1 thank you I'm retaking it before 9am tomorrow. I got a answer wrong on the test the question was -What modern-day animal is the closest to 'dinosaur' and I put cynodonts instead of birds, I get confused when they incorporate -modern day- or I probably just read to fast and mis-read the question and didn't understand or that birds is the modern day word not cynodonts or cynodonts is just completely the wrong answer obviously.
reply
Thank you I watched after taking my ecology exam 1 thank you I'm retaking it before 9am tomorrow. I got a answer wrong on the test the question was -What modern-day animal is the closest to 'dinosaur' and I put cynodonts instead of birds, I get confused when they incorporate -modern day- or I probably just read to fast and mis-read the question and didn't understand or that birds is the modern day word not cynodonts or cynodonts is just completely the wrong answer obviously.
reply
starlight
Its funny how he says he doesn't know and continues to make assumptions, I call this opinion and not facts.
And therefore I'm okay with knowing your view.
reply
Its funny how he says he doesn't know and continues to make assumptions, I call this opinion and not facts.
And therefore I'm okay with knowing your view.
reply
Hassan
Very good explanation! But why you stated that: -. the nucleic acid was probably the first genetic material. -? Is there any doubt about it?
reply
Very good explanation! But why you stated that: -. the nucleic acid was probably the first genetic material. -? Is there any doubt about it?
reply
sushil
Why mostly word comes from Greek letter?
When English is language spoken all around world
Is there anyone who'd like to answer
reply
Why mostly word comes from Greek letter?
When English is language spoken all around world
Is there anyone who'd like to answer
reply
Maria
I have to memorize all these time periods and what happened in each. Pray for me please.
Oh, and spelling counts; ;-; ;
reply
I have to memorize all these time periods and what happened in each. Pray for me please.
Oh, and spelling counts; ;-; ;
reply
Add a review, comment
Other channel videos
