Title: Beginning of Life
1Beginning of Life
2Early 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
3Alexander 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.
4Oparins 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.
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6Was he right?
- Miller Urey tested Oparins hypothesis
Water vapor, ammonia, methane, Hydrogen
Add electricity
Cool mixture to produce liquid
Collect analyze
7The Miller-Urey Experiment
Organic molecules appear here
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9After one week
- They found
- Carbohydrates, amino Acids, and other small
ORGANIC (living) molecules - Small protocells
- This evidence supported Oparins hypothesis.
10Prokaryotes 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
11The 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.
12Two other possible theories of where life began
Space!
Hydrothermal vents
13Spontaneous 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.
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15Terms 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
16Some believed that bees could form if you left
meat under your house for 23 days
Virgil-Roman Poet
17Others believed that if you left dirty clothes
out for 7 days rats would form
Jan Baptista van Helmont- physician in 1600s
18Early 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.
19The 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?
20Vital 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.
21Louis Pasteur
- French Scientist, who in 1859 finally disproved
spontaneous generation
22Pasteurs Experiment
23Biogenesis
- 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?
24Molecules of the Atmosphere
Carbon Dioxide
Hydrogen Cyanide (HCN)
25Create 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?
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28Lamarcks Theory
- Individuals can evolve to adapt to changing
conditions (acquired traits)
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30Darwins Theory
- Traits that help in survival are passed on to
offspring - Traits that do not help in survival are lost from
the gene pool
31Darwins 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