evolution
35 concepts carry this thread across the degree.
Mendel's law of segregation
Paired alleles separate into different gametes.
Mendel's law of independent assortment
Genes on different chromosomes are inherited independently.
The dihybrid cross
Predicting the 9:3:3:1 ratio of two traits.
Genetic linkage and recombination
Nearby genes tend to be inherited together.
Sex linkage
Inheritance of genes carried on the sex chromosomes.
Natural selection
Differential survival and reproduction of heritable variation.
Fitness and adaptation
Reproductive success shapes the traits of a population.
Speciation
How reproductive isolation gives rise to new species.
The evidence for common descent
Homology, fossils and molecules point to shared ancestry.
Sexual selection
Traits favoured through mate choice and competition.
The bacterial growth curve
Lag, exponential, stationary and death phases.
Antibiotic resistance
Evolution in action under drug selection.
Horizontal gene transfer
Sharing genes between unrelated lineages.
Viral replication
The lytic and lysogenic strategies.
Microbial metabolic diversity
The many ways microbes extract energy.
The Hardy-Weinberg principle
Allele and genotype frequencies in an idealised population.
Genetic drift
Random sampling changes allele frequencies.
Gene flow
Migration mixes alleles between populations.
Mutation-selection balance
Why harmful alleles persist at low frequency.
Inbreeding and heterozygosity
The genetic cost of mating with relatives.
Phylogenetics
Reconstructing evolutionary relationships from data.
The molecular clock
Dating divergence from accumulated substitutions.
Kin selection
Hamilton's rule explains altruism among relatives.
Coevolution
Reciprocal evolutionary change between interacting species.
The neutral theory
Most molecular evolution is selectively neutral.
Metapopulation dynamics
Colonisation and extinction across habitat patches.
Island biogeography
Species richness from area and isolation.
Ecological succession
How communities assemble and change over time.
Keystone species
Species with outsized effects on community structure.
r- and K-selection
Contrasting life-history strategies.
The SIR model
Compartmental modelling of an epidemic.
The basic reproduction number
R0 sets the threshold for an outbreak.
Herd immunity
The immune fraction that halts transmission.
Transmission dynamics
Contact rate, infectiousness and spread.
Vaccination strategy
Controlling disease at the population level.