Plate Tectonics & Evolution

continental crust

stays the same, consists of granite, less dense, thicker

oceanic crust

constantly changing, consists of basalt, more dense, thinner

Wagner’s discovery

proposed idea of Pangea

evidence for Wagner’s discovery

outlines of continents matched, same fossils found on different continents

Why it wasn’t accepted

he was a meteorologist and had no explanation as to how they moved

mid ocean ridge

diverging, making, oceanic

young rock middle

Iceland

subduction zone

converging, destroying, oceanic subducts

volcanoes

Pacific Ring of Fire

sliding edges

X earthquakes, San Andreas Fault

collision zone

converging, neither, continental

mountain ranges

Himalayas

convection currents

hot magma rises towards crust, spreads out, cools, sinks back down

convection currents role in movement of tectonic plates

drives shifting of tectonic plates

role of gravity in tectonic plate movement

driving force for movement of tectonic plates

gravitational force causes older material on peaks to sink to ocean floor, sinking dense crust drags rest of tectonic plate downwards - main cause of plate motion

investigation of convection currents

hot = fast

cold = slow

DNA replication

cell makes exact copy of its DNA before it divides

both cells have genetic info

mutation

if not copied properly leads to mutation

helpful mutation

mutation in bacteria that allow them to survive in presence of antibiotic drugs

harmful mutation

cancer - cells grow out of control and form abnormal masses of cells

cell division

allows organisms to produce new cells/offspring

mitosis

asexual

identical offspring

meiosis

sexual

offspring not identical

mitosis & meiosis

produce offspring, involve cell division, DNA replicate before divide

relationship between natural selection and evolution

natural selection is used to explain evolution

selecting pressures

factors that affect which organisms survive and reproduce

helps organisms adapt

relationship between age of earth and evolution of organisms

life on earth evolved from unicellular cells

as earth increases in age, life on earth becomes more complex and moves to land

natural selection steps

variation

not well adapted, selecting pressures

well adapted, reproduction, selecting pressure

population

sources of variation in population

meiosis - unique sperm and egg cells, mixes DNA

fertilization - create new combo of traits, mix of traits

mutations - random change in DNA

adaptations

characteristic that an organism has inherited and makes it suited to its environment

structural adaptations

visible structures/features/how organism is built

physiological adaptations

how organism functions

behavioral adaptations

how organism acts or behaves

transitional fossils

fossils that show characteristics similar to more that 1 group of organisms

comparative embryology

study of similarities and differences in embryonic development of different organisms

comparative anatomy

branch of science that compares and contrasts anatomy of different species

pentadactyl limb

example of homlogus structure (similar because evolved from same ancestor)

wings are analogus structure (similar function evolved differently)

biochemistry

branch of science that studies chemistry of living things

trade ancestor species

how long ago species diverged into 2

how closely related 2 species are

large differences in DNA between 2 organisms = distant common ancestor, small differences = common ancestor

fossils and fossil strata

fossil - any part of living thing preserved following death

fossil record

database of past life and evolution inferred from fossils

rock strata

helps piece together relative age of rocks/fossils

identify changes over time

biogeography

branch of sci that studies geographical distribution of living things

vestigal organs

anatomical features that no longer pay a role in that organism but were important in ancestor of that organism