Plate Tectonics Mrs. Anton. Continental Drift Caused By Plate Tectonics.
6-2/3 Notes – Biological Evidence & Plate Tectonics Chapter 6 Lessons 2 & 3.
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Transcript of 6-2/3 Notes – Biological Evidence & Plate Tectonics Chapter 6 Lessons 2 & 3.
6-2/3 Notes – 6-2/3 Notes – Biological EvidenceBiological Evidence
&&Plate TectonicsPlate Tectonics
Chapter 6
Lessons 2 & 3
Continental DriftContinental Drift• Acceptance of the continental drift
hypothesis led to the development of the theory of plate tectonics.
Continental DriftContinental Drift• As lithospheric plates move, they create
environmental changes for the organisms that live in or near them.
Continental DriftContinental Drift• The changes lead to the development of and
extinction of species.
Continental DriftContinental Drift• Australia has a large population of
mammals belonging to the group called marsupials. Few species of marsupials exist on other continents.
Geographic IsolationGeographic Isolation• Geographic isolation occurs when
populations of species are separated by a physical barrier.
Geographic IsolationGeographic Isolation• Once separated, the populations might
follow different evolutionary paths.
Geographic IsolationGeographic Isolation• The results of geographic isolation
prompted much of Darwin’s research.
Geographic IsolationGeographic Isolation• Species on an island were more similar to
those on the mainland even though the two environments were different.
Geographic IsolationGeographic Isolation• These observations led to the idea of
evolution by natural selection.
Geographic Isolation vs. Geographic Isolation vs. Convergent EvolutionConvergent Evolution
• Sometimes distant locations with similar environmental conditions have species with similar traits (analogous structures).
• The species developed independently but under similar conditions.
Geographic Isolation vs. Geographic Isolation vs. Convergent EvolutionConvergent Evolution
Octopuses and humans both have eyes - does that mean they share a recent
common ancestor?
Geographic Isolation vs. Geographic Isolation vs. Convergent EvolutionConvergent Evolution
No. Convergent evolution - when two separate groups of animals evolve to
have similar structures independently of one another.
wings of bats and birds prickly bits of porcupines and hedgehogs
Geographic Isolation vs. Geographic Isolation vs. Convergent EvolutionConvergent Evolution
• Convergent evolution results in structural and functional similarities.
• Examples include placental mammals in the Americas and marsupials in Australia.
What term describes the separation of populations by physical barriers?
A continental drift
B geographic isolation
C convergent evolution
D theory of plate tectonics
6.3 Evolution and Plate Tectonics
What did Darwin observe about geographically isolated populations?
A Species on distant islands with similar environmental conditions were similar.
B Species on islands and the mainland had undergone convergent evolution.
C Species on islands were similar to those on the mainland even though the environments were different.
D Species on the islands were more similar to each other than species on one island and the mainland.
6.3 Evolution and Plate Tectonics
What is the term for how very distantly related species can appear similar?
A geographic isolation
B recent common ancestry
C convergent evolution
D natural selection
6.3 Evolution and Plate Tectonics
What does NOT explain the gaps in the fossil record?
A Most organisms decay before fossilization.
B Fossils are unreliable for studying Earth’s history.
C Some fossils have not been found yet.
D Geological processes destroy fossils.
• Most organisms decay before fossilization.
• Some fossils have not been found yet.
• Geological processes destroy fossils.
These are the
reasons WHY.
Analogous structures are an indication of ____.
A convergent evolution
B a common ancestor
C continental drift
D geographic isolation
What does the fossil record NOT indicate?
A Species have evolved through natural selection.
B Most species that lived on Earth are extinct.
C Environmental conditions on Earth have not changed much.
D In Earth’s early history, life was less complex.