Major Events in Earth’s History

What event occurred 4.6 billion years before the present?

• Earth forms

• Human ancestors appear

• Dinosaurs become extinct

• Cyanobacteria fossils appear

Tags

NGSS.HS-ESS1-6

What event occurred 3.5 billion years before the present?

• Earth forms

• Human ancestors appear

• Dinosaurs become extinct

• Cyanobacteria fossils appear

Tags

NGSS.HS-ESS1-6

What event occurred 66 million years before the present?

• Earth forms

• Human ancestors appear

• Dinosaurs become extinct

• Cyanobacteria fossils appear

Tags

NGSS.HS-LS4-5

NGSS.HS-LS4-2

What event occurred 4.4 million years ago before the present?

• Earth forms

• Human ancestors appear

• Dinosaurs become extinct

• Cyanobacteria fossils appear

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

Earth’s early atmosphere was different from today’s atmosphere. About 2.7 billion years ago, oxygen began to accumulate in the atmosphere. Which of the following events likely occurred at the same time in Earth’s history?

• a photosynthetic bacteria appeared on Earth

• a mass extinction recently occurred

• Earth was experiencing an ice age

• early humans first evolved

Tags

NGSS.HS-ESS2-7

NGSS.HS-LS2-5

One of the most significant mass extinctions occurred at the end of the Paleozoic era. During this time, most species on Earth died out. Which of the following factors are likely to have contributed to a mass extinction event on Earth? Select all that apply.

• Several volcanoes may have erupted at the same time, producing debris that blocked energy from the sun and prevented photosynthesis.

• A rise in global temperatures may have occurred too quickly for populations to adapt to the changes.

• A widespread food shortage may have wiped out large numbers of living things in a short period of time.

• The oxygen levels in the ocean were increasing, causing ocean animals to suffocate and die out in large numbers.

Tags

NGSS.HS-LS4-5

NGSS.HS-ESS2-2

NGSS.HS-ESS2-4