So, how has the Earth & LIFE changed over its 4 So, how has the Earth & LIFE changed over its 4.6 billion years existence?

This is known as our GEOLOGIC TIME SCALE

WORK WITH YOUR SEAT PARTNER Let’s make a GEOLOGIC TIME SCALE on a strip of paper like the paper towel one I have on my wall. WORK WITH YOUR SEAT PARTNER

MAKE YOUR STRIP 46 inches long!

MAKE YOUR STRIP 46 inches long! (46 inches = 4.6 BILLION yrs)

COLOR the 1st 7 inches light red

The sun, earth and moon were forming.

It’s called “HADEAN”era…like Hades.

That’s because our Earth was a volcanic fireball for its first It’s called “HADEAN”…like Hades. That’s because our Earth was a volcanic fireball for its first 0.7 billion years!

The next 16 inches shade BLUE

3.8bya-2.5bya Unicellular prokaryotes thrive That’s because the next 1.6 billion years the Earth got covered in OCEAN! Archean Era: 3.8bya-2.5bya Unicellular prokaryotes thrive

The next 16 inches shade BLUE Draw a bacteria here! The next 16 inches shade BLUE

3.8bya-2.5bya Unicellular prokaryotes thrive During this time, LIFE BEGAN as PROKARYOTIC BACTERIA in this WATER! Archean Era: 3.8bya-2.5bya Unicellular prokaryotes thrive

the next 17 inches shade in GREEN

The next 17 inches shade in GREEN. You should have 6” left.

complex unicellular eukaryotes grew Proterozoic Era: 2.5bya—540mya complex unicellular eukaryotes grew

complex unicellular eukaryotes grew This 17 inches represents the 1.7 billion years that cyanobacteria were photosynthesizing in the waters on Earth. Proterozoic Era: 2.5bya—540mya complex unicellular eukaryotes grew

complex unicellular eukaryotes grew Photosynthesis begins with phytoplankton! It gives Earth what important gas for life? Proterozoic Era: 2.5bya—540mya complex unicellular eukaryotes grew

OXYGEN is being produced by cyanobacteria / algae / phytoplankton

this ENTIRE FIRST 4 BILLION YEARS on Earth is called PRECAMBRIAN (only what existed?)

the ENTIRE FIRST 4 BILLION YEARS on Earth is called PRECAMBRIAN (only microbes exist)

PRECAMBRIAN EON

PRECAMBRIAN EON (era) was IMPORTANT for LIFE on Earth! FIRST 4.0 BILLION YEARS OF EARTH HISTORY SUN, EARTH, then MOON formed, OCEANS formed LIFE began simply (one cell at-a-time). Our ATMOSPHERE was created through volcanoes & from photosynthesizing bacteria (algae, phytoplankton) making OXYGEN,

Only the last 600 million years complex life has evolved

Let’s zoom into this .6 billion years!

We’ve only had complex life only recently on Earth…this last We’ve only had complex life only recently on Earth…this last .6 billion years.

Mark 3. 5 inches (. 35 billion yrs Mark 3.5 inches (.35 billion yrs.) as PALEOZOIC (plants, bugs, & fishes

Of this last 6 inches of our GEOLOGIC TIME SCALE, 3 Of this last 6 inches of our GEOLOGIC TIME SCALE, 3.5 inches are the PALEOZOIC era or 350 million years of fishes, plants and bugs.

…

Mark 2 in. (.2 billion yrs.) as MESOZOIC (amphibiansreptiles, dinosaurs ruled)

Dinosaurs ruled!

The last .65 inch (65,000,000 years) flowers and MAMMALS thrived during the CENOZOIC ERA!

The LAST 65 million years, we MAMMALS thrive during our CENOZOIC era!

The LAST 65 million years, we MAMMALS thrive during our CENOZOIC era! .65 inch = 65,000,000 YEARS!!

PRECAMBRIAN EON COMPLEX LIFE HERE

PRECAMBRIAN EON COMPLEX LIFE HERE GEOLOGIC TIME SCALE

MAJOR EXTINCTION EVENTS! PRECAMBRIAN EON COMPLEX LIFE HERE GEOLOGIC TIME SCALE broken up into MAJOR EXTINCTION EVENTS!

MAJOR EXTINCTION EVENTS! PRECAMBRIAN EON COMPLEX LIFE HERE GEOLOGIC TIME SCALE broken up into MAJOR EXTINCTION EVENTS!

See how we’ve only had complex life only recently on Earth.

See how we’ve only had complex life only recently on Earth.

See how we’ve only had complex life only recently on Earth. LIFE had to START OVER at EACH of these ERAS!