15.4 + 15.6 + 15.7 + 15.9 Major Events in History of Life, Continental Drift , Mass Extinctions, Fossil Record Flashcards
Macroevolution
evolutionary change above the species level, encompassing the origin of a new group of organisms through a series of speciation events and the impact of mass extinctions on the diversity of life
Earth’s age can be split into ____ of geological time
4 eons
What are the 4 eons of geological time
1) The Hadean Eon
2) The Archaen Eon
3) The Proterozoic Eon
4) The Phanerozoic Eon
The Hadean Eon
origin of Earth
What was the year range of the Hadean Eon?
4 - 4.6 bya
What was the year range of the Archaen Eon?
2.5 - 4 bya
What happened during the Archaean Eon?
1) Life started with prokaryotes
2) Surge in Oxygen
3) Start of Photosynthesis
When did life with prokaryotes start?
3.5 bya
When was there a surge in oxygen?
2.7 - 2.2 bya
What did the surge of oxygen cause?
was detrimental to many organisms
What was the year range of the proterozoic eon?
0.6 - 2.5 bya
What occured during the Proterozoic Eon?
1) First Eukaryotic Cell
2) First Multicellular Eukaryotes
3) Cambrian Explosion
When did the first eukaryotic cell appear?
1.8 bya
When did the first multicellular eukaryotes appear?
1.3 bya
When did the Cambrian Explision occur
0.6 bya
Cambrian Explosion
the huge emergence of animals
What was the age range of the Phanerozoic Eon?
0.6 bya - present
What occured during the phanerozoic eon
Colonization of Land
Colonization of Land
organisms inhabit land/water
What did the colonization of land occur?
0.4 bya
Geologic Record
a time scale established by geologists that divide Earth’s history into 4 eons; Hadean, Archean, Proterozoic, and Phanerozoic - and further subdivides into eras, period, and epochs
When was the Paleozoic Era?
541 million years ago
Paleozoic Era
contain fossils of lineages that led to present day organisms and extinct organisms
What were the early organisms in the Paleozic Era?
aquatic organisms
What were the later organisms in the Paleozoic Era?
land organisms
Mesozoic Era is also known as
the middle animal era and the “age of reptiles”
The Mesozoic era was the end of the
cretacous
Mesozoic Era
saw first mammals and flowering plants and is when dinosaurs became extinct
Did all dinosaurs become extinct during the Mesozoic Era?
no; all except for birds
The extinction of the dinosaurs was one of the
5 mass extinctions
Cenozoic Era is aka the
recent animal era or the “age of mammals “
When did the Cenozoic Era occur?
66 million years ago
The Cenozoic Era is split into ___ because…
epochs because there is more known about it
Pangea
the supercontinent that formed near the end of the Paleozoic Era, when plate movements brought all the landmasses of Earth together
What did Pangea end
the paleozoic era
What did Pangea cause
the permenian extinction
When did Pangea start to break up
during the Mesozoic Era
Mass extinctions
occur when global environmental changes are rapid and disrupt more than 50% of Earth’s species
How many mass extinctions are there?
5
What are the most known extinctions?
the extinctions ending the Permian and Creatcous periods
When did the Permian Extinction occur?
252 million years ago
What was the Permian Extinction a boundary between?
the paleozoic and mesozoic eras
What did the Permian extinction wipe out (percentages)?
Wiped out 96% of marine species and 70% of terrestrial life
What was the Permian Extinction caused by
Caused by volcanic eruptions, ash, noxious gasses, less oxygen etc.
When did the Cretaceous Extinction occur?
66 million years ago
What did the Cretacous Extinction wipe out (percentages)?
Wiped out half of marine species and some terrestrial plants and animals
Was the Earth dominated by dinosaurs during the Cretacous Extinction?
no
What was the Cretacous Extinction caused by?
Iridium found in clay in sediments that separate the Mesozoic and Cenozoic eras from a large asteroid
Will there be a 6th mass extinction
there might be one
Why would there be a 6th mass extinction
bc of human activities and global warming/climate change
