evolution a population changes over time. charles darwin (1809- 1882)

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)