evolution Flashcards
Theory
Well supported and testable explanation of something that has occurred in the world
Evolution
The process b which ancient organisms change to make modern and more complex organisms
Geologic time
the billions of years of earths history
Fossil record
Collection of fossils that explain the history of organisms on earth
Relative dating
Age of fossils is determined by comparing the placement and other fossils in other layers
Radioactive dating
use of half lives to date a sample
Early forms of life
Single celled simple organisms sported by fossils
modern life
multicellular complex organisms
Jean Baptiste Lamark
French naturalist
published theory in 1809
Inheritance of Acquired characteristics
Post birth changes that can be inherited by offspring
Lamarck’s theory
Use & Dispute
If a structure was used more then it became stronger but if you didnt use it it became weaker or disappear (Lamarck’s theory)
Charles Darwin
Born Feb 12 1809
Collected plant and animal species and sent them back to London
Charles Darwin’s theory of natural selection
The environment of a spicie gives some organisms an advantage due to their traits leading them to be able to reproduce and survive (doesn’t change genetic makeup)
Long term effects of natural selection
More organisms with beneficial/desirable traits
Less organisms with non desirable traits
spices is “evolving”
Conditions for natural selection
Overpopulation - More organisms will be born than environment can handle
Competition - struggle for food, water, and existence
Variation - Some organisms will have different traits due to mutations
Adaptive value - Some traits will be superior
Fitness - ability for an organism to survive and reproduce in it environment
Spices
Organisms that can mate and produce offsprings (DNA makeup must be similar)
Darwin’s finches
Color and shape of beak differed as vegetation changed on the island.
Desirable traits
Speed - ability to escape prey
Camouflage - Abilty to hide from prey
Break shape - Ability to get food
Size of leaves - Ability to do more photosynthesis
Ability to store water
Modern day theory of evolution
A combination of knowledge of genetics and Darwin’s theory of natural selection
Tree of evolution
Common ancestors to all
All spices on one branch share much in comments genetically
More modern day species
Gradualism
Change is slow over a long period of time
Common ancestor
Intermediate forms
Punctuated equilibrium
Changes are rapid in a short period of time and nothing for a long period of time
Few intermediate forms
Evidence supporting evolution
Fossils
Homologous structures
Vestigial structures
Embryology
Biochemical similarities
Fossils
Remains of living things
found in rock layers
Homologous structures
Parts of an organisms with similar shape. Different comment ancester
Vestigial Structures
Have no effect on survival but aren’t removed
Embryology
Study of embryos. Supports common ancestor theory
Biochemicals similarities
Similar DNA and protein
Sources of varieation
Sexual reproduction - 2 gametes combine
Crossing over - Exchange of genes during meiosis
Mutations- Change of DNA
Structural
Physical variations that allow for organisms to survive
Functional
Genetic variations that help an organism to survive
Behavioral
Behaviors or appearance based variations that help an organism
Geographical isolation
Mountains or geological formations that splits a spices into two populations.
New species
Rate of evolution
Organisms with shorter life spans will evolve faster
Extinction
The entire spices cannot survive in the environment
Adaptive characteristics no long help survival
