Evolution Flashcards
Evolution
the process by which a species changes over time
Use & Disuse Theory
Jean Baptiste Lamark
“All species descend from other species”
some internal force causes an organisms to produce offspring slightly different from self
The part of the body that were extensively used would become larger and stronger, whereas those parts not used would waste
Inheritance of acquired characteristics
Inheritance of acquired characteristics
During the life of an organism, they could acquire characteristics to help them survive better, any changes acquired can be past to offspring.
Weismann’s experiement
Cut the tail 22nd consecutive generations of mice, the 23rd generation of mice still born with tail.
Debunking Lamark’s theory
What is the location that Darwin most known for?
Galapagos Island
What animal did Darwin study?
Finches & Iguanas
What did Darwin propose about the finches on the island?
The finches on the island evolved from a single species of finch from S. America mainland.
What are the two parts of Darwin’s theory?
Common descent & adaptation
Common Descent
all species have a single common ancestor
Adaptation
modifications that enable organisms to be better suited for their environment
What causes adaptations?
mutations
What was Darwin’s theory called?
Natural Selection
Variations
the difference among individuals in a species
What causes variation among individuals in a species
mutations
What are the types of evolution?
Macroevolution & microevolution
Macroevolution
Changes beyond species
- biogeography
- fossil record
- homology
-biochemical similarities
- chromosomal similarities
Microevolution
changes within a gene pool , change in the allele frequencies in population over generations
- kettleworth months
-insect resistance
- drug resistance
Biogeography
the geographic distribution of species
How are fossils related with evolution
the succession of fossil forms is congruent with the theory of descent with modificaton
What are the two components of comparative anatomy?
homologous structure & vestigial organs
Homologous Structure
body parts in different organisms have similar bones and similar arrangements of muscles, blood vessels, and nerves and undergo similar embryological development, but do not necessarily serve the same purpose
Vestigal Organ
the remains of a structure that was functional in some ancestor but is no longer functional in the organism in question
Comparative Embryology
a comparison of early stage of their embryonic development may show similarities that suggest a common ancestry
Molecular Biology/Biochemical Similarities
DNA, RNA, amino acids and proteins have all been used to determine evolutionary relationships b/tw organisms
The greater the difference b/tw DNA in organisms…
the longer time has passed since the two organisms have had a common ancestor.
What does genetic variation in population contribute to?
evolution
Most species exhibit what type of variation?
geographic variation
What causes variation?
mutations
What increases genetic variation?
sexual reproduction
Population
a group of individuals belonging to the same species
Hardy-Weinberg Equilbrium requirements
large population-no genetic drift
no immigration-emigration-no gene can be removed or added
no mutations
must be random mating, no sexual selection
no natural selection- all traits must have an equally aid in survival
