Evolution Flashcards
Descent with Modification
Charles Darwin, species are descendants of ancestral species that were different from present day species
Evolution
change in genetic composition of a population
What does Evolution measure?
Change in allele frequency
What ship did Charles Darwin travel on?
The beagle
What did Aristotle classify organisms into?
Scale of Nature
Carolus Linneaeus
develop binomial naming system and Hierarchy
Hierarchy
Species – genus – family – order – class – phylum - kingdom
What was also part of Darwins ideas
fossils in different layers of rock
Lamarck’s Evolution
compared fossils to present day species and discovered line between them
Lamarck’s Principle
use and disuse, inheritance
Use and disuse
parts of an organism used a lot get bigger and stronger
Inheritance
inheritance of these special characteristics
What was flawed about Lamarck’s Principle
acquired traits can not be passed down to the next generation
Natural Selection
individuals with certain traits leave more off spring than other individuals with out that trait
Adaptations
Characteristics of organisms that enhance their survival and reproduction in specific environments
4 Observations that led to natural selection
- members in the population vary in traits
- traits are inherited by off spring
- Species are able to produce more off spring than the environment can support
- many of these offsprings do not survive
Artificial Selection
Human modification of species over many generations by selecting and breeding individuals that possess desired traits
Two summary of Natural Selection
- Over time natural selection can lead to increase matching of organisms and environment
- Changes in environment could lead to new species via natural selection
Evidence of Evoulation
- Direct Observation of Evolutionary Change
- Fossils can show evolutionary change over time
- Homology
- Biogeography
Law of Succession
Living relatives of fossil species
Fossil Evidence
Law of Succession, Transitional Forms
Homology
Characteristics present in ancestral organism are altered in its descendants
Homologous Structures
Variations of structural theme present in a common ancestor
Vestigial structures
Lost most or all of past function
Convergent evolution
independent evolution of similar features in different lineages
Evolutionary tree
diagram that reflects evolutionary relationships among groups of organisms
Cell Division
All cells must have come from another cell
Why do cells split
Reproduction, growth and development, tissue renewal
Cell Cycle
Life of a cell from when formed to when it divides into two cells
How does most cell division result from
Indentical sister cells, split DNA equally among two resulting cells
Two types of Reproduction
Asexual Reproduction, Sexual reproduction
Asexual Reproduction
creation of genetically identical offspring from one parent
Sexual Reproduction
creation of offspring by fusion of sperm and egg
Binary Fission
Replication of DNA split into two daughter cells
Prokaryotes
Single long DNA molecule
Eukaryotes
DNA packaged into chromosomes(made from chromatin DNA and proteins)