Transcript Proving Spontaneous Generation Wrong

How old is the earth?
• Currently humans
have dated the earth
to 4.5 BILLION years
old.
• We arrive at this date
using Radiometric
Dating
Radiometric Dating
• The radioactive decay
(break down) of
Uranium into Lead is
used to date rocks.
• Uranium turns into
Lead at a constant
rate so it is like an
internal clock for
rocks.
• Half-life is 4.5 b.y.
Proving Spontaneous Generation
Wrong
• In the 1600s Francesco Redi showed that
maggots were the offspring of flies and did not
simply form out of raw materials.
Spallanzani’s Experiment
• In the 1700s Lazzaro Spallanzani showed that
microorganisms did not spontaneously
form.
Spontaneous Origin Not
Spontaneous Generation
• Life Sprang from a
“primordial soup” of
raw materials.
• Materials found on
the early earth were…
• Nitrogen (N2)
• Carbon Dioxide
(CO2)
• Methane (CH4)
• Hydrogen (H2)
• Ammonia (NH3)
Miller-Urey Experiment
• In 1953 Miller and
Urey created an
apparatus to make
organic molecules out
of raw materials found
on the early earth.
• Did create Amino
Acids out of H2, CH4,
and NH3
Chemosynthesis
• Most scientists believe
that the first cells that
formed needed to form
deep in the ocean around
vents since the ozone
layer had not formed yet.
• The use of chemicals and
heat to create sugar is
called Chemosynthesis
Cell Like Structures
• Since Miller-Urey
scientists have been
able to create two
different cell like
structures out of raw
materials that are
very similar to cell
membranes of today.
• Microspheres and
Coacervates
RNA is Self Replicating
• Many scientists believe that RNA was the
first genetic information formed and
ultimately led to heredity.
First Photosynthetic Cells
• The first
photosynthetic cells to
form were
cyanobacteria.
• The modern version
of these bacteria are
called stromatolites
• Fossils of these
bacteria date to 3.5
bya.
Eukaryotes form from Prokaryotes
• The current
hypothesis for the
formation of complex
Eukaryotic cells is
called
endosymbiosis
• Chloroplasts and
Mitochondria used to
be free living bacteria.