Engines of the Planet Lecture Flashcards
What has been the most important factor in causing major, long-term changes in the patterns of organism distribution? (over geological time)
the movement of continents! (Plate tectonics)
the movement of land masses across latitude bands resulted in land masses lying in different ____ regions
climatic
= huge impact on organisms on the land masses
Tectonic plate movement is responsible for:
- formation of: (list 3)
- destruction of: (list 1)
formation of mountain chains, volcanic islands, and epeiric or epicontinental seas
destruction of epeiric/ epicontinental seas as well
How do epeiric/ epicontinental seas form? What are 2 implications of them?
- sea levels rise and oceans flood continental plates
- acted as barriers to terrestrial organisms, sub-dividing the landmasses into smaller regions
- provided a habitat in which diverse marine life could thrive
By the end of the Cambrian, ___ fragments had broken away from a supercontinent (Rodinia) that formed over 1 billion years ago
3
when did the ancient continents consolidate?
during the carboniferous + permian periods of the paleozoic era
The consolidation of the ancient continents resulted in the formation of _____ _______, and eventually, _______…
mountain ranges
the supercontinent Pangaea and the global Panthalassic ocean
What are the implications of having one supercontinent and a global ocean?
great connectivity and exchange b/w terrestrial and marine biotas
- eg. pangaea and the global panthalassic ocean
separation of the Laurasian and Gondwanan continents during the mesozoic era began as a ____ ____ and expansion of the ___ ___.
What did this lead to?
rift valley
Atlantic sea
This separation eventually led to the opening of the circum-equatorial seaway
The onset of the cenozoic era was marked by:
the impact of the chicxulub asteroid and mass extinctions, which were followed by diversification of mammals and other surviving lineages
What resulted in the uplift of the Himalayas?
the continents continued to drift apart, sometimes colliding with isolated landmasses
- this resulted in the rapid northward lifting of India and its eventual impact with Asia, caused the uplift of the Himalayas
Continued drifting of the continents during the Neogene and Quaternary periods resulted in most landmasses ____ of the equator.
What might this have contributed to?
north
may have contributed to the climatic instability that set the stage for the glacial cycles of the Pleistocene epoch
T/F
No contribution to biogeography has had more of an impact than the theory of continental drift, and later, plate tectonics theory
false
the theory of evolution probably had a bigger impact
BUT closely followed by plate tectonics/ cont. drift, so it was very important
Who noted that the continents fit together?
Antonio Snider-Pellegrini
Who further extended the concept that the continents fit together?
alfred wegener (starting in 1910)
the theory of plate tectonics provided a mechanism for ______ _____
continental drift
What is a strong piece of evidence for plate tectonics?
mid-ocean ridges and sea floor spreading!
- magnetic fields recorded in the ocean floor
- the ocean floor is a conveyor belt that is being continuously formed at the mid-ocean ridge & destroyed at the trenches, with the continents passively riding along on the conveyor belt
How do magnetic fields get recorded in the ocean floor?
-oceans are formed by the addition of material & spreading at mid-oceanic ridges
- moving away from ridge, the ocean floor increases in age
- pattern of alternating magnetic stripes caused by reversals in earth’s magnetic field
- rocks are formed at the mid-ocean ridge and move away, maintaining their original polarity
- very convincing evidence!
In geological time, what do most major boundaries represent?
periods of mass extinction, followed by adaptive radiation of surviving species
Earliest prokaryotic cells appeared around ____ years ago, and they resemble modern ______ ______
3.5 billion years ago
modern photosynthetic algae
The rise of photosynthesis had what effect on CO2 and O2 levels?
Evidence of this?
reduced atmospheric CO2 and created oxygen!
evidence= deposition of extensive iron oxide sediments on marine continental shelves
Give 2 further pieces of evidence for the rise of photosynthesis (and subsequent oxygen introduction)
- stromatolites in limestone built by photosynthetic cyanobacteria
- extensive banded iron formations
cambrian explosion=
a sudden diversification of life forms and body plans, most of which are extinct today
One of the richest fossil records of the Cambrian explosion can be found where?
Burgess shale!
By Field, BC
