1 Intro to Evolution, Biodiversity and Deep Time Flashcards
(19 cards)
What are the 6 propositions of Neo-Darwinian theory?
1) Reproduction
2) Excess - potential for huge numbers of any species
3) Variation
4) Environmental selection
5) Divergence - eventually leading to speciation
6) Ancestry - life and biodiversity is fluid and changing
What is biodiversity?
The variety of life, in all its manifestations. It encompasses all forms, levels and combinations of natural variation
What is taxonomy?
The science of classification of organisms
What is phylogeny?
The study of evolutionary relationships
What is neo-Darwinian evolution?
Descent with modification through natural selection
What are the 3 eras in the Phanerozoic eon?
Paleozoic 570 - 245mya
Mesozoic 245 - 65mya
Cenozoic 65 - 1.64mya
What periods are in the Cenozoic era?
Paleogene
Neogene
Quaternary
What periods are in the Mesozoic era?
Triassic
Jurassic
Cretaceous
What periods are in the Paleozoic era?
Cambrian
Ordovician
Silurian
Devonian
Carboniferous
Permian
What eras are in the pre-Cambrian eon?
Hadean 4.57 - 3.95bya
Archean 3.95 - 2.5bya
Proterozoic 2.5 - 0.57bya
How much of Earth’s history is pre-Cambrian?
88%
What is the mnemonic for the Phanerozoic eon?
Cats often sit down carefully, possibly to just cry pathetically not quietly
What are the ways of studying biodiversity?
Through the living world and extant organisms
Through the fossil record of extant and extinct organisms
Why is the fossil record incomplete?
1) Very few of the organisms that ever live will end up being fossilised (then collected and studied)
2) Entire species or higher taxa may not be preserved in the fossil record:
- low preservation potential e.g. not bones or teeth
- small population
- small geographical area
- lived for a short period of time
Why is the fossil record biased?
1) Certain environments more likely to be preserved
- those with net deposition rather than erosion
- marine organisms more likely to be preserved than terrestrial
- terrestrial lowland deposits preserved rather than upland deposits
2) Fossils of aquatic organisms much more likely to be preserved
3) Organisms with recalcitrant tissues more likely to be preserved e.g. bone, teeth, shell rather than soft bodies
How is Earth variable?
Spatially variable - Sahara vs Arctic
Temporally variable - Diurnal, seasonal
Environment has also changed over long or vast periods of time
What are examples of long term environmental change?
Solar luminosity - brighter now
Distance between earth and moon
Continental drift, plate tectonic events
Atmosphere change, climate change
Milankovitch cycles
Evolving biota
What are examples of short term and rare events?
Large Igneous Provinces (LIPs)
Short-medium term atmospheric change
Super eruptions
Meteroite impacts
Tsunamis
Mass extinctions
What are LIPs?
Where the surface of the Earth breaks open and lava flows out -> causing mass extinctions
