Chapters 14-17

Change over time Spontaneous Generation: Living organisms arise from non-living things. Many experiments were conducted to disprove spontaneous generation.

SCIENTISTDISPUTED THEORY CONCLUSIONS Francesco Redi (1600’s) Maggots come from rotting meat Maggots come from eggs laid by flies Lazzaro Spallanzani (1700’s) Microorganisms come from a vital force in the air Microorganisms travel in the air Louis Pasteur (1800’s) Boiling destroys air’s vital force Solid particles in the air transport microorganisms.

Redi—Spallanzani—

Pasteur--

Formation of Simple Organic Compounds Alexander Oparin, 1923 (H2O, H2, CH4, & NH3) Formation of Complex Organic Compounds Amino acids formed chains in early atmosphere Concentration & Enclosure of Organic Compounds Coacervates & Microsphere formed Evolution of Growth, Metabolism, & Reproduction

Approximately 4.6 – 3.5 billion years ago. First organisms – Prokaryotic cells Eukaryotic cells – 1 billion years ago Endosymbiont Theory – Eukaryotic mitochondria evolved from bacteria & chloroplasts evolved from cyanobacteria.

We can find evidence of evolution by examining fossils & modern day organisms

Dating fossils Carbon-dating Position in sedimentary rock Formation of the Fossil Record Types of fossils: Mold Cast Imprint

Common ancestry Hawaiian honeycreepers Homologous structures Similar embryologically, but have different functions Vestigial organs Functionless parts Biochemistry Similar biochemical metabolism Embryological Development Fish, rabbits, gorilla

Jean Baptiste de Lamarck ( ) Before Darwin Inheritance of Acquired Characteristics “If you don’t use it, you lose it” Natural Selection Organisms with favorable variations survive & reproduce at a higher rate

Variation exists among individuals of a species. Scarcity of resources in an increasing population will lead to competition Individuals with advantageous variations are more likely to survive & reproduce.

CONVERGENT EVOLUTION DIVERGENT EVOLUTION Type of Environment SimilarDifferent Two or more species Similar but unrelated Related but different ExamplesCactus & euphorbia Red fox & kid fox

The joint change of two or more species in close interaction. Example: Plants & animals that pollinate them

Population All members of the same species living in a particular location at the same time Gene Pool Collection of genes for all the traits in a population Allele Frequency Percentage of a specific allele of a gene in the gene pool Genetic Equilibrium Allele frequencies stay the same from generation to generation

A population will remain in GENETIC EQUILIBRIUM if all of these conditions are met: No Mutations Individuals neither enter nor leave a population Population is large Individuals mate randomly Natural selection does not occur

Mutation Migration Natural Selection Genetic Drift A phenomenon by which allele frequencies in a population change as a result of random events or change.

Stabilizing Selection Favors average form (ex. Lizard) Directional Selection Favors one extreme form (ex. Anteaters) Disruptive Selection Favors both extreme forms (ex. Limpets) Sexual Selection

SPECIATION Formation of a new species.

Geographic Isolation Physical separation of members of a populations Reproductive Isolation Results from barriers of successful breeding between population groups in the same area