Origin Of Life And Evolution Notes Flashcards
What are fossils?
Any evidence an organism once lived
What can scientists determine by looking at fossils?
What ancient climate they lived in and the behavior of organisms
What layer of rock do fossils form in?
Sedimentary
What are the two types of fossils? Briefly describe each one.
- cast-space filled in with minerals like a dinosaur bone
* mold-like print
Are younger fossils found closer to or farther from the surface?
Younger fossils are found closer to the surface, while older fossils are found farther from it.
What are the two types of dating? Briefly describe each one.
- relative-can only tell which one is younger/older
- radiometric-uses carbon and sophisticated machines to determine age (carbon 14-radioactive isotopes that decay or break down over time)
How many mass extinctions (where almost everything died off) were there, according to the fossil records?
Five mass extinctions
Spontaneous generation
People once thought things appeared or were formed from the air and not from other living things.
When did the earth form?
About 4.6 billion years ago
What did Francesco Redi prove and how did he prove it?
Francesco Redi disproved spontaneous generation trough his meat-in-a-jar experiment. But, he couldn’t explain where microorganisms came from, so he said there was a “vital force” that made them appear.
What is biogenesis?
Some scientists thought living organisms MUST come from other living organisms.
What experiment did Louis Pasteur perform?
He did a broth experiment where he boiled some broth in two flasks, then closed one of them off.
What did Louis Pasteur find out from his experiment?
He found out that if there was no air or no way for bacteria to get in, then the broth stays good. But, if the bacteria can get in, then the broth goes bad. He determined living things come from other living things.
What was Earth’s atmosphere originally made of (billions of years ago)?
Water vapor, methane, and ammonia.
Who believed that life came from the oceans?
Alexander Oparin
Who did experiments with Earth’s original atmospheric stuff and added electricity?
Stanley Miller and Harold Urey
What did Miller and Urey get?
Things needed for life like amino acids, sugars, and organic compounds (made of carbon…)
Who heated the amino acid solutions?
Sidney fox
What did Fox call what formed?
Protocells-they’re like regular cells, but they don’t carry out all of the processes living things need to do.
What are prokaryotes?
The first real living cells, most of which were anaerobic (didn’t need oxygen to survive).
By what process did prokaryotes get energy?
Fermentation (not respiration because they didn’t need oxygen)
Were prokaryotes heterotrophs?
Yes, because they had to “get” their own food.
What formed after a couple of hundred million years that could make their own food?
Autotrophs
What did autotrophs put into the atmosphere?
Oxygen
What were the first autotrophs called and where could they live?
Archaebacteria, and they could live in got sulfur springs & deep sea ocean vents.
What happened after autotrophs appeared?
They produced lightning, storms with lots of oxygen lead to ozone.