Presented byDaquine Hebert & John Williams

Evolution

Evolution in a nutshell

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Allele FrequencyThe measure of the relative frequency of an allele at a genetic locus in a population;

expressed as a proportion or percentage.

Analogous StructureA physical structure, present in multiple species, that is similar in function but different in

form and inheritance.

EmbryologyThe branch of zoology studying the early development of living things.

Endosymbiosis

A theorized process in which early eukaryotic cells were formed from simpler prokaryotes.

EvolutionA process in which new species develop from preexisting species (biological evolution or

macroevolution);a change in the allele frequencies of a population of organisms from generation to generation (genetic evolution or microevolution).

Extinction

A term that typically describes a species that no longer has any known living individuals.

FossilsThe preserved remains or traces of organisms that once lived on Earth.

Founder Effect

A decrease in genetic variation caused by the formation of a new population by a small number of individuals from a larger population.

Vocabulary

Genetic DriftA change in the allele frequency of a population as a result of chance events rather than natural selection.GradualismA proposed explanation in evolutionary biology stating that new species arise from the result of slight modifications (mutations and resulting phenotypic changes) over many generations.Homologous StructureA physical characteristic in different organisms that is similar because it was inherited from a common ancestor.Isolating MechanismsIf mating can take place, there are four factors that prevent hybrid viability: zygotic mortality (fertilization but no zygote), hybrid inviability (embryo is not viable), hybrid sterility (resulting adult is sterile), and hybrid breakdown (first generationis viable but future generations are not).Migration (Genetics)The permanent movement of genes into or out of a population resulting in a change in allele frequencies.

Natural SelectionA process in nature in which organisms possessing certain inherited traits are better able to survive and reproduce compared to others of their species.Punctuated EquilibriumA proposed explanation in evolutionary biology stating that species are generally stable over long periods of time. Occasionally there are rapid changes that affect some species which can quickly result in a new species.Selective BreedingThe process of breeding organisms that results on offspring with desired genetic traits.SpeciationA process typically caused by the genetic isolation from a main population resulting in a new genetically distinct species.SpeciesThe lowest taxonomic level of biological classification consisting of organisms capable of reproduction that results in fertile offspring.Vestigial StructureA physical characteristic in organisms that appears to have lost its original function as a species has changed over time.

Quiz Time

7 Written questions A proposed explanation in evolutionary biology stating that new species

arise from the result of slight modifications (mutations and resulting phenotypic changes) over many generations.

The process of breeding organisms that results on offspring with desired genetic traits.

A physical characteristic in organisms that appears to have lost its original function as a species has changed over time.

A physical characteristic in different organisms that is similar because it was inherited from a common ancestor.

A term that typically describes a species that no longer has any known living individuals.

A proposed explanation in evolutionary biology stating that species are generally stable over long periods of time. Occasionally there are rapid changes that affect some species which can quickly result in a new species.

The measure of the relative frequency of an allele at a genetic locus in a population; expressed as a proportion or percentage.

6 Multiple choice questions

6 Multiple choice questions A physical structure, present in multiple species, that is similar in function but different in form and inheritance.

•  Vestigial Structure•  Homologous Structure•  Analogous Structure•  Natural Selection

A process typically caused by the genetic isolation from a main population resulting in a new genetically distinct species.•  Speciation•  Evolution•  Extinction•  Species

A change in the allele frequency of a population as a result of chance events rather than natural selection.•  Speciation•  Species•  Genetic Drift•  Extinction

The preserved remains or traces of organisms that once lived on Earth.•  Evolution•  Species•  Fossils•  Gradualism

The permanent movement of genes into or out of a population resulting in a change in allele frequencies.•  Selective Breeding•  Migration (Genetics)•  Gradualism•  Natural Selection

A decrease in genetic variation caused by the formation of a new population by a small number of individuals from a larger population.•  Fossils•  Genetic Drift•  Founder Effect•  Species

6 True/False questions Endosymbiosis → A process in which new species develop from preexisting species

(biological evolution or macroevolution);a change in the allele frequencies of a population of organisms from generation to generation (genetic evolution or microevolution).

 True         False Embryology → A process in which new species develop from preexisting species (biological

evolution or macroevolution);a change in the allele frequencies of a population of organisms from generation to generation (genetic evolution or microevolution).

 True         False Species → The preserved remains or traces of organisms that once lived on Earth.  True         False Natural Selection → A process in nature in which organisms possessing certain inherited

traits are better able to survive and reproduce compared to others of their species.  True         False Isolating Mechanisms → A process in which new species develop from preexisting species

(biological evolution or macroevolution);a change in the allele frequencies of a population of organisms from generation to generation (genetic evolution or microevolution).

 True         False Evolution → A process in which new species develop from preexisting species (biological

evolution or macroevolution);a change in the allele frequencies of a population of organisms from generation to generation (genetic evolution or microevolution).

 True         False

Hardy-Weinburg Equilibrum Large population: can occur so that the loss

or gain of genes does not change the gene pool.

NO gene flow: populations must be isolated. No immigration(out) or emigration (in)

NO mutations: Mutations always occur so this condition can not occur

Random Mating: Mating is NEVER random. This condition can never be met. There is always variation.

Some Problems! Sixteen percent of a population is unable to

taste the chemical PTC. These nontasters are recessive for the tasting gene.

1. What percentage of individuals in are tasters?

2. What is the frequency of the dominant and recessive allele?’

3. What percentage of the population are heterozygous for the trait?

The Basics Allele Frequency: p+q=1. This

pertains to the allele and not the individual itself.

Gene Frequency: p^2+2pq+q^2=1. This pertains to the individual. What trait does the individual have?

Example Six out of twenty people have black

hair(dominant). What is the allele frequency of the

dominant trait? 14 out of twenty people have red

hair(recessive). What is the allele frequency? What is the gene frequency of the

dominant and recessive traits?

Do it on your own! The delta-32 mutation, a recessive

gene, gives humans protection from HIV infection. The allele frequency in a town in Sweden is 20%.

1. What percent of the population have two copies of the gene and are therefore immune to HIV?

2. What percent of the population are less susceptible to the disease since they are heterozygous?