Lec 4/5 Flashcards
Deep time
Geological or cosmic time (millions/billions of years)
Deep time effects
Natural selection can occur as variable selective pressures arise
Extant variables are results of
Long history of adaptation
Geological timescale includes
Precambrian
Paleozoic
Mesozoic
Cenozoic
Paleozoic includes
Cambrian
Silurian
Devonian
Carboniferous
Mesozoic includes
Triassic
Jurassic
Cretaceous
Selected factors (3)
Continental drifts
Atmospheric oxygen levels
Potentials for speciation
Continental drifts
Landmass of the Earth move substantially over geological time
Plate tectonics
Crusts of the Earth move and collide to reshape to Earth’s landscape
Continental drifts cause
Changes of oceanic circulation
This transports heat, temp, nutrients etc.
Changes in eustatic sea level cause
Land bridges to be exposed
Continental drifts cause the formation of a
Epicontinental seaway ( sea on the continent)
Atmospheric oxygen level
Key element creating ATP through aerobic cellular respiration
Contributor to growth/ development
Can be toxic
Atmospheric oxygen level changes causes
Vertebrates to need to adapt in order to survive
Speciation
Formation of barriers to gene flow between populations
Types of speciation
Allopatric
Sympatric
Allopatric speciation
Physical isolation of populations