Beginning of Life. Early Earth= not a friendly place Atmosphere was mostly methane, nitrogren, water...
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Transcript of Beginning of Life. Early Earth= not a friendly place Atmosphere was mostly methane, nitrogren, water...
Early Earth= not a friendly placeEarly Earth= not a friendly place
Atmosphere was mostly Atmosphere was mostly methane, methane, nitrogren, water vapor, and ammonianitrogren, water vapor, and ammonia… … nearly no oxygennearly no oxygen
The earth was very The earth was very hothot with many with many volcanoes exploding at oncevolcanoes exploding at once
Many Many thunder and lightning stormsthunder and lightning storms
Alexander OparinAlexander Oparin
Believed that life began in the oceans.Believed that life began in the oceans.He believed that sun and lightening made He believed that sun and lightening made
organic molecules form.organic molecules form.Rain then washed these molecules into the oceans Rain then washed these molecules into the oceans
and made a and made a primordial soup.primordial soup.
Oparin’s hypothesisOparin’s hypothesis
RainRain + + earth’s heatearth’s heat + + lightninlightning + g + COCO22= =
life’s first lipid membrane in a shape of a life’s first lipid membrane in a shape of a spheresphere
The small sphere of lipid membrane is The small sphere of lipid membrane is called a called a protocellprotocell. .
These were located in the These were located in the oceanocean and were and were the very first beginnings of life.the very first beginnings of life.
Was he right?Was he right?
Miller & UreyMiller & Urey tested Oparin’s hypothesis tested Oparin’s hypothesis
Water vapor, ammonia, methane, Hydrogen
Add electricity
Cool mixture to produce liquid
Collect & analyze
After one week…After one week…
They found:They found:Carbohydrates, amino Acids, and other small Carbohydrates, amino Acids, and other small
ORGANIC (living) molecules ORGANIC (living) molecules Small protocellsSmall protocells
This evidence supported Oparin’s hypothesis. This evidence supported Oparin’s hypothesis.
Prokaryotes evolved to become Prokaryotes evolved to become eukaryotes by endosymbiosis: eukaryotes by endosymbiosis: Big Big
cells swallow little cells that cells swallow little cells that perform specific functionsperform specific functions
Prokaryote ingests aerobic bacteria
Aerobic bacteria produces energy inside prokaryote
Prokaryote ingests cyanobacteria
Cyanobacteria contains photosynthetic pigments
Mitochondria
chloroplasts
The very first cells were The very first cells were autotrophsautotrophs
They made their energy from the They made their energy from the sunsun..
Because they were doing photosynthesis, Because they were doing photosynthesis, they were releasing they were releasing oxygenoxygen into the into the atmosphere.atmosphere.
This allowed more complicated life to This allowed more complicated life to evolve.evolve.
Spontaneous GenerationSpontaneous Generation
Believed that simple living organisms Believed that simple living organisms could come into being by spontaneous could come into being by spontaneous generation. generation. non-living non-living objectsobjects can give rise to living can give rise to living
organismsorganisms. . It was common “knowledge” that simple organisms It was common “knowledge” that simple organisms
like worms, beetles, frogs, and salamanders could like worms, beetles, frogs, and salamanders could come from dust, mud, etc., and food left out, come from dust, mud, etc., and food left out, quickly “swarmed” with life. quickly “swarmed” with life.
Terms to Know
Prefix for without? A-
Word for beginning? Genesis
Prefix for life? Bio-
Biogenesis=beginning with life
Life beginning from a non living thing
Abiogenesis
Spontaneous generation = abiogenesis
Jan Baptista van Helmont- physician in 1600s
Others believed that if you left dirty clothes out for 7 days rats would form
Early Thoughts?Early Thoughts?
Spontaneous Generation- the idea Spontaneous Generation- the idea nonliving material can produce lifenonliving material can produce life
1668- Francesco Redi1668- Francesco RediDisproved the idea that decaying meat Disproved the idea that decaying meat
produced maggots (immature flies)produced maggots (immature flies)Disproved the spontaneousDisproved the spontaneous
generation of large generation of large
organisms.organisms.
The first true experiment?Open Jars
Closed Jars
Francesco Redi -1600s Italian scientist
Did this show that life did not come from non-life?
Even with different types of meat closed jars=no maggots
Disproves spontaneous generation
Vital SourceVital Source
Scientists thought that there must be a Scientists thought that there must be a vital source in the air that makes vital source in the air that makes microscopic organisms grow. microscopic organisms grow. In the mid 1800’s Louis Pasteur designed an In the mid 1800’s Louis Pasteur designed an
experiment that disproved the spontaneous experiment that disproved the spontaneous generation of microorganisms.generation of microorganisms.
In his experiment air, but not microorganisms In his experiment air, but not microorganisms could touch the broth. could touch the broth.
Louis PasteurLouis Pasteur
French Scientist, who in 1859 finally French Scientist, who in 1859 finally disproved spontaneous generationdisproved spontaneous generation
BiogenesisBiogenesis
This experiment led to the idea that:This experiment led to the idea that:Living organisms come only from other Living organisms come only from other
organisms. organisms.
But how did life START on Earth?But how did life START on Earth?How does life come from non-life 4.6 billion years How does life come from non-life 4.6 billion years
ago?ago?
Create your own Primordial Soup Create your own Primordial Soup CansCans
Include:
1. Ingredients
2. How to make it
An early theory of evolution was proposed
by Jean Lamarck
Lamarck proposed organisms acquired traits during their lifetime and passed them on to their offspring. This is known as Lamarckism.
What is wrong with this theory?
Lamarck’s TheoryLamarck’s Theory
Individuals can Individuals can evolve to adapt evolve to adapt to changing to changing conditions conditions (acquired (acquired traits)traits)
Darwin’s TheoryDarwin’s Theory
Traits that help in Traits that help in survival are passed survival are passed on to offspringon to offspring
Traits that do not Traits that do not help in survival are help in survival are lost from the gene lost from the gene poolpool
Darwin’s Theory of Natural Selection
1. There is variation in individuals.
2. Living things over-reproduce.
3.There is a struggle to survive.
4.Those that survive are the most fit.
Who was Charles Darwin?How Does Evolution Really Work?How do we know Evolution Happens? How do we know Evolution Happens?
https://www.youtube.com/watch?v=ewtw_nZUIDQ