Chapter 25: The History of Life on Earth

Match the following dates to what occurred at the time.

• 1.8 BYA

• cambrian explosion

• 535 MYA

• atmospheric oxygen

• 440 MYA

• jawed vertebrates appeared

• 2.7 BYA

• prokaryotic cells appear

• 3.5 BYA

• eukaryotic cells appear

Match the following dates to what occurred at the time.

• 195,000 YA

• humans

• 500 MYA

• tetrapods

• 375 MYA

• flowering plants

• 140 MYA

• land is colonized

Match the following dates to what occurred at the time.

• 66 MYA

• Neoproterozoic Era

• 2.5 MYA

• Cenozoic Era

• 252 MYA

• Paleozoic Era

• 541 MYA

• Mesozoic Era

How many billions of years ago did first life appear?

Mathematical Equivalence

ON

How many billions of years ago did the first oxygen producers arise?

Mathematical Equivalence

OFF

How many billions of years ago did the first eukaryotic organism appear?

Mathematical Equivalence

OFF

How many billions of years ago did the first multicellular organism appear?

Mathematical Equivalence

OFF

How many millions of years ago did the Cambrian explosion occur?

Mathematical Equivalence

OFF

How many millions of years ago did the first land dwelling animals appear?

Mathematical Equivalence

OFF

How is it theorized that life began on earth?

• Protocell membranes maintained internal chemistry

• Organic Molecule

  --->

  Macromolecules

• Self replicating molecules

• Abiotic Synthesis