Learn: MAST 316 Evolution and Hardy-Weinberg

Vestigial structure

Structures that have reduced in size/function because they no longer serve a purpose.

Homologous structure

Shared characteristics based on shared ancestry.

DNA sequence

Similarities and differences in nucleotide sequences between organisms.

Fossil record

Remains of long-dead organisms providing historical evidence of evolution.

Biogeography

Geographical distribution of plants and animals across the planet.

Analogous structure

Shared characteristics based on shared environmental pressure rather than common ancestry.

Descent with modification

The core concept and definition of evolution.

DNA contribution to evolution

Offers a mechanism for trait inheritance and biological variability.

Epigenetic inheritance

Heritable changes in gene expression not caused by changes in the DNA sequence.

Level at which evolution acts

Populations over generations; individuals cannot evolve.

Convergent evolution

Development of similar traits in unrelated species due to similar environments, resulting in analogous structures.

Gene

A sequence of DNA that codes for a specific trait.

Allele

Different versions or variants of a gene.

Genotype

An individual's combination of alleles for a particular gene.

Phenotype

An individual's measurable or observable physical trait.

Homozygote

An individual who has two copies of the same allele for a gene.

Heterozygote

An individual who has two different alleles for a gene.

Allele frequency

How common an allele is within the gene pool of a population.

Genotype frequency

How common a specific genotype is within a population.

Phenotype frequency

How common a specific observable trait is within a population.

Population

A group of individuals with a high probability of interbreeding and capable of producing fertile offspring.

Most common type of mutation

Substitution.

Hardy-Weinberg allele equation

p + q = 1

Hardy-Weinberg genotype equation

p² + 2pq + q² = 1

Meaning of p in Hardy-Weinberg

Frequency of the dominant allele in a gene pool.

Meaning of q in Hardy-Weinberg

Frequency of the recessive allele in a gene pool.

Meaning of p² in Hardy-Weinberg

Frequency of the homozygous dominant genotype (AA).

Meaning of 2pq in Hardy-Weinberg

Frequency of the heterozygous genotype (Aa) or carriers.

Meaning of q² in Hardy-Weinberg

Frequency of the homozygous recessive genotype (aa) and recessive phenotype.

Hardy-Weinberg Step 1 (Recessive Phenotype)

Turn the recessive percentage into a decimal to find q².

Hardy-Weinberg Step 2

Take the square root of q² to find q.

Hardy-Weinberg Step 3

Subtract q from 1 (1 − q) to find p.

Calculating carriers in Hardy-Weinberg

Calculate the heterozygous frequency using 2pq.

Genotypes showing dominant phenotype

AA and Aa (assuming A is dominant).

Genotype showing recessive phenotype

aa