Hadean Eon
Archean Eon
Proterozoic Eon
Phanerozoic Eon
Biogenesis - all living things come from other living things
Spontaneous Generation - a process by which living things come from nonliving things
Francesco Redi’s Experiment
Lazzaro Spallanzani’s Experiment
Louis Pasteur’s Experiment
How did first life originate?
Steps needed for life:
RNA WORLD
The RNA World Hypothesis states that the first molecule of genetic storage was not DNA, but RNA!
Although the Hadean era was very rough (asteroids bombarding the earth, frequent volcanic eruptions, noxious atmosphere, high temperatures), around ~4 bya, there were signs of life
Possible theories:
Chemical evolution needs 8 reaction conditions as of now:
Evidence of Evolutionary Change
Evolution - genetic changes in a population of organisms over time
Selection - is the survival and reproduction of individuals with certain traits.
Fitness - is the ability of organisms to survive and reproduce for the next generation
Survival - (did they live or did they die?)
Mating success - (did they mate?)
Fecundity - (# of babies made)
Artificial Selection: Humans select the traits of plants and animals that are passed onto the offspring.
Natural Selection: Nature selects the traits that get passed to the next generation.
Sexual Selection: A type of natural selection where the best traits increase the chances of successfully having offspring.
Random Selection (genetic drift): is when a trait survives because it was chosen at random.
sexual dimorphism - A trait that differs between males and females of a species.
bottleneck - Reduction in population size so severe that it reduces genetic diversity.
gene flow - The movement of alleles between populations.
genetic drift - Change in allele frequency due to chance alone.
inbreeding - Mating among close relatives.
Selections can shift traits in three ways: Directional, Stabilizing, and Disruptive
Examples:
Population Genetics - the study of evolution from a genetic perspective, focusing on the change of allele frequency over time
Gene Pool - The total genetic information available in a population.
Allele Frequency - the proportion of a specific allele in a population
microevolution - Change in allele frequency of a gene in a single population
macroevolution - significant evolutionary change in multiple populations
These concepts are used in the Hardy-Weinberg Equilibrium
Five assumptions of HWE -
Previously, species were defined by:
Species - a unique type of organism that has a genus name and specific epithet. Also, a group of individuals that can potentially interbreed, produce fertile offspring, and do not interbreed with other groups.
Speciation - the formation of a new species. Occurs when members of a species become isolated and can no longer reproduce.
adaptive radiation - A lineage undergoes a burst of genetic divergences that gives rise to many species.
coevolution - The joint evolution of two closely interacting species; each species is a selective agent for traits of the other.
exaptation - A trait that has been repurposed during evolution.
extinct - Refers to a species that no longer has living members.
key innovation - An evolutionary adaptation that gives its bearer the opportunity to exploit a particular environment much more efficiently or in a new way.
macroevolution - Large-scale evolutionary patterns and trends.
stasis - Evolutionary pattern in which a lineage persists with little or no change over evolutionary time
Important People
how to solve hardy weinberg equilibrium problems