ANTH 1-5 Flashcards
Evolutionary Mechanism 3: Genetic Drift
change in allele frequencies due to sampling error (chance).
Reduces variation within populations but increases variation among populations.
Evolutionary Mechanism 4: Natural Selection
Decreases within a population. It can increase or decrease variation between populations, depending on the type of selection. This evolutionary mechanism is the only one that produces adaptations.
Founder effect
The reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population.
Population bottleneck
an event that drastically reduces the size of a population
sexual selection
individuals with traits that are more attractive to potential mates are more likely to reproduce, leading to those traits becoming more common in the population.
even if the same trait also carries more significant risks for the individual’s long-term survival
artificial selection
process by which humans intentionally breed plants or animals for specific traits, selecting individuals with desirable characteristics to reproduce.
Logical Fallacies in Evolution
Evolution as progress
The naturalistic fallacy
Evolution is presented inaccurately as “survival of the fittest.”
Social Darwinism
The belief that helping the poor and sick would get in the way of evolution, which depends on the survival of the fittest, led in the 1920s directly to Eugenics (artificial selection on human populations as government policy)
What did Darwin have a hard time explaining
inheritance of traits—specifically how variations in traits were passed down from one generation to the next. Was later clarified by the discovery of Mendelian genetics.
What is Modern Synthesis
combines Darwinian evolution with Mendelian genetics, explaining how natural selection operates on genetic variation to drive evolution.
what is mendelian genetics
the study of inheritance patterns based on Gregor Mendel’s principles, which include the concepts of dominant and recessive traits.
norm of reaction
The range of phenotypes that a single genotype can produce when exposed to different environmental conditions
phenotypic plasticity
the ability of an organism to change its phenotype in response to environmental conditions
What are the ways in which variation is created and maintained in a population?
Mutation
● Recombination in meiosis
● Polygenic traits
● Gene regulation
● Phenotypic Plasticity
Recombination in Meiosis:
involves the exchange of genetic material between chromosomes, creating new combinations of alleles in offspring.
Gene Regulation
controls when and how genes are expressed, influencing the production of proteins and the resulting phenotype.
Trade-Offs
where a trait that provides an advantage in one context may be disadvantageous in another (sickle-cell anemia)
Why is Nature vs. Nurture a false dichotomy?
because both genetic factors (nature) and environmental influences (nurture) interact and shape an individual’s traits, behaviors, and development. Rather than being separate or opposing forces.
