evolution a population changes over time. charles darwin (1809- 1882)
TRANSCRIPT
Evolution
A population changes over time
Charles Darwin (1809- 1882)
Lamarck- Inheritance of Acquired
Characteristics
Must be Genetic You cannot “ force” yourself to have a
characteristics Ex. You cannot force yourself to be
lactose tolerant Bacteria CANNOT acquire resistance to
antibiotics
New traits cannot be created during your lifetime
Only genes can be passed on
Lyell
Fossils
Darwin’s Finches Biogeography- geographic distribution of life
forms
Galapagos Islands- Volcanic islands off the coast of South America Species were slightly different than the ones on the
mainland
Finches- different beaks depending on the food available Cactus eating finch-more point beak
Insect eating finch- sharp ( trees)
Types of seeds
All descended from one mainland Finch DESCENT WITH MODIFICATION from a
COMMON ANCESTOR
Blue Footed Boobie
Natural Selection Mechanism for evolutionary change
1. Inherited variations: Mutations- changes in DNA
Meiosis
2. Not all individuals survive
3. Adaptations( traits that help an organism be more suited to the environment) increase survival and reproductive success ( Fitness- reproductive success)
4. Genes for adaptations increase in each generation
Artificial Selection
The result of Natural Selection is a population adapted to the local environment
Types of Natural Selection
Evidence for Evolution
1.Fossils
2.Biogeographical
3.Anatomical
4.Biochemical
5.Embryology
6.Examples- Antibiotic
Fossils
Biogeography
Anatomical Evidencea. Homologous Structure: Structures that are similar because they are inherited from a common ancestor
Anatomical Evidence b. Analogous Structures: features are similar in function but not in structure. They do not derive from a recent common ancestor but in response to a similar environment.
ANALOGOUS STRUCTURES
Anatomical Evidence C. Vestigial structures: no longer have
function. occur because organism inherit anatomy from their ancestors. Ex. Some snakes have small hindlimbs
Humans: Appendix, wisdom teeth, tail bone
THE APPENDIX
VESTIGIAL STRUCTURE
KOALA
EUCALYPTUS
Biochemical Living organisms use DNA, and many
identical enzymes (same 20 amino acids)
Degree of similarity of DNA sequence or amino acid structure based on how closely related
Embryology( Development)
Embryology (Development)
Embryos of closely related organisms often have similar stages in development.
Causes of Microevolution1. Mutations are the raw material for
evolutionary change
2. Gene Flow-
3. Non random mating
4. Genetic Drift
Speciation ( Macroevolution)