UNIT 7 ck12’s 5.18-5.19 Flashcards
What is needed for evolution to occur according to Darwin?
Heritable variations
Darwin was unaware of Mendel’s laws of genetics.
What determines variations of traits?
Different alleles
These variations are heritable.
What is evolution due to?
A change in alleles over time.
What is microevolution?
Evolution occurring over a relatively short period of time within a population or species.
What is macroevolution?
Evolution occurring over geologic time above the level of the species.
What does the fossil record reflect?
Macroevolution.
What results from microevolution taking place over many generations?
Macroevolution.
Do individuals evolve?
No.
What is a population?
Organisms of the same species that live in the same area.
What is population genetics?
The science that focuses on evolution within populations.
What does population genetics combine?
Evolutionary theory and Mendelian genetics.
What is the genetic makeup of an individual called?
Genotype
The genotype refers to the specific genetic constitution of an individual.
What is the term for the collection of all genes in a population?
Gene pool
The gene pool includes all genetic information from all members of the population.
What does the gene pool include for each gene?
All the different alleles
Alleles are different versions of a gene that may exist within the population.
How is a population characterized in terms of its gene pool?
By the frequency of different alleles
The frequency indicates how common each allele is within the population.
What is allele frequency?
How often an allele occurs in a gene pool relative to the other alleles for that gene.
In a population of 100 members, how many total copies of each gene are there?
200
How many copies of each gene does each member of a sexually reproducing species have?
Two copies
If a gene exists in two forms, what are these forms called?
Alleles
What is the definition of evolution in a population?
Evolution occurs when allele frequencies change over time.
Who were the founders of the Hardy-Weinberg theorem?
Godfrey Hardy and Wilhelm Weinberg
Hardy was an English mathematician and Weinberg was a German doctor.
What does the Hardy-Weinberg theorem demonstrate?
Allele frequencies do not change in a population if certain conditions are met.
What is a population in Hardy-Weinberg equilibrium?
A population where allele frequencies remain constant under certain conditions.
List the five conditions for Hardy-Weinberg equilibrium.
- No new mutations are occurring
- No migration
- The population is very large
- Mating is at random
- No natural selection
