Describe Earth 4.6 Million Years ago
Molten rock, solid crust formed 500 million years later, no oxygen, gases from volcanoes
Define Fossil
Any preserved form of an organism
What is the Law of Superposition
Younger layers of rock are on top of older layers
What is Radiometric Dating?
Uses the half-life of isotopes (how long it takes for 1/2 isotope to decay) and compare the size of the parent and daughter isotope
What is Relative Dating
Method of dating rocks by comparing them to other layers of rock
What rocks can be used for Radiometric Dating?
Igneous and metamorphic
What was the Cambrian Explosion?
Most major animal groups diversified
What is the K-T extinction?
The impact of a meteorite brought high levels of iridium
What is the Permian Extinction?
90% of marine organisms died
What is the theory of a Spontaneous Generation
The idea that life appears from non-life
What is the theory of Biogenesis?
Only living organisms can produce another living organism
What is the Primordial Soup Hypothesis?
That organic molecules were created from gas reactions in the early ocean
What is the Endosymbiont Theory
Original eukaryotic cells lived within prokaryotic cells
What was Darwin’s Natural Selection?
Those better equipped to handle changes will survive and those less will die
Define Variation in Natural Selection
Organisms in a population vary (some taller than others)
Define Heritability in Natural Selection
Variations are inherited from parents (tall parents have tall children)
Define Overproduction in Natural Selection
Populations produce more offspring than will survive (will have a bunch of seeds, only a few will grow)
Define Reproduction Advantage in Natural Selection
Some variations are better for reproduction (tall flowers survive better than small)
Define Evolution
Gradual changes in organisms
What is the difference between an ancestral trait and a derived trait?
Derived traits are newly evolved features and not seen in ancestors, ancestral traits are seen in ancestors
Define Homologous Structures in Comparative Anatomy
Structures that have similar structures inherited from a common ancestor (How humans and horses have the same leg development, but they move differently, how dolphins and bats have the same limb development, but dolphins use it for swimming and bats for flying)
Define Vestigial Structures in Comparative Anatomy
Structures that are from a common ancestor, but don’t sure use anymore (the appendix, Kiwi wings that are too small for flight)
Define Analogous Structures in Comparative Anatomy
Analogous Structures are features that have similar uses, but are structurally unrelated. (Bird wings vs. bat wings, penguin fins vs. dolphin fins)
Define Embryology in Comparative Anatomy
The comparison of embryos for homologous structures before birth, even if those traits aren’t present after full development (how bird and mammal embryos both have a head and tail)
