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Beginning of Life

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Beginning of Life * Early Earth= not a friendly place Atmosphere was mostly methane, nitrogren, water vapor, and ammonia nearly no oxygen The earth was very hot ... – PowerPoint PPT presentation

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Title: Beginning of Life


1
Beginning of Life
2
Early Earth not a friendly place
  • Atmosphere was mostly methane, nitrogren, water
    vapor, and ammonia nearly no oxygen
  • The earth was very hot with many volcanoes
    exploding at once
  • Many thunder and lightning storms

3
Alexander Oparin
  • Believed that life began in the oceans.
  • He believed that sun and lightening made organic
    molecules form.
  • Rain then washed these molecules into the oceans
    and made a primordial soup.

4
Oparins hypothesis
  • Rain earths heat lightning CO2 lifes
    first lipid membrane in a shape of a sphere
  • The small sphere of lipid membrane is called a
    protocell.
  • These were located in the ocean and were the very
    first beginnings of life.

5
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6
Was he right?
  • Miller Urey tested Oparins hypothesis

Water vapor, ammonia, methane, Hydrogen
Add electricity
Cool mixture to produce liquid
Collect analyze
7
The Miller-Urey Experiment
Organic molecules appear here
8
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9
After one week
  • They found
  • Carbohydrates, amino Acids, and other small
    ORGANIC (living) molecules
  • Small protocells
  • This evidence supported Oparins hypothesis.

10
Prokaryotes evolved to become eukaryotes by
endosymbiosis Big cells swallow little cells
that perform specific functions
Prokaryote ingests aerobic bacteria
Prokaryote ingests cyanobacteria
Aerobic bacteria produces energy inside
prokaryote ?
Mitochondria
Cyanobacteria contains photosynthetic pigments ?
chloroplasts
11
The very first cells were autotrophs
  • They made their energy from the sun.
  • Because they were doing photosynthesis, they were
    releasing oxygen into the atmosphere.
  • This allowed more complicated life to evolve.

12
Two other possible theories of where life began
Space!
Hydrothermal vents
13
Spontaneous Generation
  • Believed that simple living organisms could come
    into being by spontaneous generation.
  • non-living objects can give rise to living
    organisms.
  • It was common knowledge that simple organisms
    like worms, beetles, frogs, and salamanders could
    come from dust, mud, etc., and food left out,
    quickly swarmed with life.

14
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15
Terms to Know
Prefix for life?
Bio-
Word for beginning?
Genesis
Biogenesisbeginning with life
Prefix for without?
Abiogenesis
A-
Life beginning from a non living thing
Spontaneous generation abiogenesis
16
Some believed that bees could form if you left
meat under your house for 23 days
Virgil-Roman Poet
17
Others believed that if you left dirty clothes
out for 7 days rats would form
Jan Baptista van Helmont- physician in 1600s
18
Early Thoughts?
  • Spontaneous Generation- the idea nonliving
    material can produce life
  • 1668- Francesco Redi
  • Disproved the idea that decaying meat produced
    maggots (immature flies)
  • Disproved the spontaneous
  • generation of large
  • organisms.

19
The first true experiment?
Open Jars
Francesco Redi -1600s Italian scientist
Disproves spontaneous generation
Closed Jars
Even with different types of meat closed jarsno
maggots
Did this show that life did not come from
non-life?
20
Vital Source
  • Scientists thought that there must be a vital
    source in the air that makes microscopic
    organisms grow.
  • In the mid 1800s Louis Pasteur designed an
    experiment that disproved the spontaneous
    generation of microorganisms.
  • In his experiment air, but not microorganisms
    could touch the broth.

21
Louis Pasteur
  • French Scientist, who in 1859 finally disproved
    spontaneous generation

22
Pasteurs Experiment
23
Biogenesis
  • This experiment led to the idea that
  • Living organisms come only from other organisms.
  • But how did life START on Earth?
  • How does life come from non-life 4.6 billion
    years ago?

24
Molecules of the Atmosphere
Carbon Dioxide
Hydrogen Cyanide (HCN)
25
Create your own Primordial Soup Cans
  • Include
  • Ingredients
  • How to make it

26
  • 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?

27
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28
Lamarcks Theory
  • Individuals can evolve to adapt to changing
    conditions (acquired traits)

29
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30
Darwins Theory
  • Traits that help in survival are passed on to
    offspring
  • Traits that do not help in survival are lost from
    the gene pool

31
Darwins Theory of Natural Selection
  • 1. There is variation in individuals.
  • 2. Living things over-reproduce.
  • There is a struggle to survive.
  • 4.Those that survive are the most fit.

32
  • Who was Charles Darwin?
  • How Does
  • Evolution Really Work?
  • How do we know Evolution Happens?
    https//www.youtube.com/watch?vewtw_nZUIDQ

33
  • Why does evolution matter now?
  • https//www.youtube.com/watch?vW-WumllRPLI
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