Transcript Precambrian Era 10Bx - Ms. Marcos` Biology Wiki

The Precambrian
Time
Felipe González.
Valentina Stozitzky.
María Alejandra
Vargas.
Daniela Ramos.
Daniel Pérez.
10B
4.5 billon years
ago
The earth was
born!!!
Geologists and paleontologists
4
Stop! Notice fabulous table on
your book
• Geologic time scale
-relative, absolute
dating.
-major divitions of the
geologic time scale.
Eons
Era
Periods
PRECAMBRIAN
• It means before the
“cambrian period”.
• Before the formation of
rocks with recognizable fossils.
•Cryptozoic or "obscure
life“.
90%
Divided into three Eons
Hadean
Archean
Proterozoic
cambrian Environment
Scientist think that seas
were created by a volcanic
catalist.
The planet developed a
solid crust that created water
vapor.
Oxygen began to be
produced in large
quantities.
The atmosphere was
reduced into gases and
oxygen.
Oxygen had chimical
reactions: Iron and
oxidable surfaces.
The seas had a
green bright tone.
The planet had
a redish tint.
Important info…
Scientists think the first seas
gave rise to life.
hot, mineral-rich volcanic vents
actied as catalysts for chemical
reactions .
The water bubbles that
formed-1st cell
membranes.
Other bubbles contained selfreplicating substances.
chemicals around them
combined to produce energyusing, living cells.
Forms of life
The first living organism were microscopic
bacteria founded in fossils.
Fossilized bacteria and blue-green
algae 3,500 million years ago.
Protozoa.
Found mainly in the oceans.
Eukaryotic cells2,100 million
years after.
Invertebrates.
Evolved later on (700 million
years ago)
Sponges, corals, jelly fish
HADEAN
EON
From 4567 to 3800 mya.
The big bang
•Formation of the Solar
System
•Formation of the Earth.
•Moon is created.
•Oceans of liquid rock,
boiling sulfur, and impact
craters everywhere.
•The air is hot, thick, steamy.
•No oxygen
-water vapor.
-carbon dioxide.
•No rocks of this time have
been found.
Splashh!
ARCHAEAN
EON
From 3800 to 2500
•Surface of the Earth
molten solid rock.
•Water
condensed in
liquid form.
• 1st Prokaryotes
•15 hours long.
appeared.
-oxygen producing bacteria.
- cyanobacteria (blue-
green algae).
•The continents have not formed yet.
(global ocean)
•Atmosphere (75% nitogen,15%
carbondioxide.)
PROTEROZOIC EON
Divided in Era and Periods
•Paleoproterozoic Era
Siderian Period
- Stable continents first appeared.
•free oxygen is found
-oceans and atmosphere.
•Oxygen catastrophekilled many
organisms.
•Start of
Huronian ice
age.
From 3800 to 2500
PROTEROZOIC EON
•Rhyacian Period
- Organisms with mitochondria
capable of aerobic respiration
appear.
•Orosirian Period
- Mountain development
- Oxygen starts accumulating in the
atmosphere
•Statherian Period
-single-celled life appeared.
- lots of bacteria and archaeans.
From 3800 to 2500
PROTEROZOIC EON
•Mesoproterozoic Era
Calymmian Period )
- Oxygen builds up in the atmosphere.
- Formation of ozone layer.
- Eukaryotic (nucleated) cells appear.
From 3800 to 2500
•Ectasian Period
- lots of green (Chlorobionta) and red
(Rhodophyta) algae.
•Stenian Period
- Spore-gamete formation  sexual reproduction.
- Formation of the supercontinent.
16
• http://www.prehistory.com/precambrian.htm
• http://fossils.valdosta.edu/era_precambrian.
html
• http://www.scientificpsychic.com/etc/timelin
e/timeline.html
• http://www.geo.msu.edu/geogmich/Precam
brian.html