Topic Test 1 Flashcards
Trait
Any observable characteristic of an individual
Phenotype
Refers to what value of trait is observed used to generally refer to a number of different trait values
Quantitative trait
Phenotype can be measured on a continuous scale ex. Height
Qualitative trait
Phenotype is measured in a categorical scale ex. Dwarfism Have it or not
Morphological trait
Phenotype has to do with the shape, structure, colour, pattern or size of an individual/species
Behavioural trait
Phenotype had to do with the behaviour of individual/species
Life history trait
Related to timing of development and reproduction of offspring; number/size of offspring
Traits with no genetic component
Phenotypes determined only by the environment
Heritable trait
Traits with phenotypes that are genetically inherited from biological parents (DNA)
Heritability
A measure of how important genetics are to determining a trait
Phenotypes for traits that are highly heritable will be more likely to look like the phenotype of biological parents- regardless of environment
Phenotypic plasticity
When the exact same genotype produces different phenotypes under different environments
Ex. 2 plants with same genotypes but ones in dark is short and other is in light is tall
Sexual dimorphism
Traits are sexually dimorphic if they vary between biological sexed in species, usually specific to certain traits
Ex. Deer 🦌 (antlers for males and nine for females), angler fish
Only relevant for dioecious species
Dioecious species
Species that have separate males and females
Taxonomic hierarchy
Based on ancestry
Kingdom, phylum, class, order, family, genus, species
Biological units of organization
Another way of classifying organisms: Biosphere, ecosystem, community, population, organism, organ system, etc.
Biodiversity
Usually refers to the total number of different species
Evolution
The process that results in changes in the proportion of heritable traits within populations from one generation to the next
4 mechanisms of evolution
- Natural selection
- Mutation
- Genetic drift
- Gene flow
(All are simultaneously and continuously acting in every population of living organism)
Natural selection
Evolutionary mechanism
Only mechanism that leads to adaptions
Adaptions
Traits that provide a fit between an organism and the environment
Darwin’s postulates
1.phenotypic variation exists within a population
2. Different reproduction/survival occurs based on that phenotypic variation
3. That variation is genetically heritable
When these postulates are true, natural selection is occurring
Fitness
Reproductive success
A measure of how many surviving offspring an organism produces
The fittest organisms are most successful at passing in their genes
Directional selection
Distribution of a trait in a single direction (ex. Finches in drought +beak depth increasing)
Stabilizing selection
Genetic variants that lead to extremes becoming less common in the population over time