Variation Flashcards
What is Microevolution?
Short term changes within a species over a few generations
List the 4 evolutionary processes
- Natural Selection
- Mutation
- Gene Flow
- Genetic Drift
What is a polytypic species?
A species composed of local populations that express different traits
List 5 Static Races according to Blumenbach
- Caucasoid
- Mongoloid
- Malay
- Ethiopian
- American Indian
What is Neo-Darwinism (MES)
Modern Evolutionary Synthesis- combined Darwin’s natural selection and Mendel’s hereditary concepts and recognizes that humans are all one species
What is a cline?
Gradual change in phenotypes between populations
What causes a cline?
Environmental pressures and gene flow from neighbouring populations
What is Evolutionary Genomics?
Assessing the difference in genomes between related species in an attempt to show lineage and evolutionary timeline of species
What is a haplotype?
Group of alleles that are inherited together. Correspond to ethnicity in terms of social history and migration patterns.
What is a disease marker?
A genetic marker for various diseases that is linked to ancestry.
What causes phenotype variation?
Genes and Environment
List the 3 types of natural selection
- Directional Selection
- Stabilizing Selection
- Disruptive Selection
What is Directional Selection. Example?
Drives a trait to one extreme while acting against the other extreme. Peppered moth
What is Stabilizing Selection? Example?
Drives a trait to the average while acting against the extremes. Peacock tails
What is Disruptive Selection? Example?
Drives a trait to both extremes while acting against the average. Rocket Pocket mice
What is adaptation?
The mutual shaping of organisms and their environment to reach homeostasis
Lis 4 types of Adaptations
- Genetic Adaptations
- Developmental Adaptations
- Short-term Adaptations
- Cultural Adaptations
What is a Genetic adaptation? Example?
Irreversible biological change that alters allele frequency and happens at a population level via mutation, natural selection, and inheritance. Sherpa people
What is a Developmental adaptation? Example?
Sometimes irreversible biological change that doesn’t alter allele frequency and happens at an individual level. Ribcage size
What is a Short-term adaptation? Example?
Completely reversible change that does not affect alleles and genes and happens at an individual level. Red blood cell count
What is a Cultural adaptation? Example?
Change of behaviour and use of material culture due to environmental conditions that doesn’t change allele frequency. Oxygen
What is niche construction?
When an organism modifies the environment to make it suitable to live in
List 3 biocultural adaptations
- Skin Colour
- Body Size
- Disease
3 stages of skin adaptation to UV exposure
first exposure - acclimatization - tanning
prolonged exposure - developmental - skin thickening
generational exposure - darker pigmentation
What is Bergmann’s rule?
Smaller bodies are adapted to hot environments, while larger bodies are adapted to cold environments.
What is Allen’s rule?
Longer limbs are adapted to hot environments, while shorter limbs are adapted to cold environments
2 Heterozygous (AS) parents chances
25% AA - die of malaria
25% SS - die of sickle cell
50% AS - healthy
