1001 1-2 Flashcards
Natural Selection
the process by which organisms that are best suited to their environment are more likely to survive and reproduce. This process causes species to change over time.
Stabilizing Selection
average traits have more reproductive
success
Directional Selection
One extreme of the trait has more
reproductive success
Disruptive Selection
Both extremes of a trait have more
reproductive success
Modes of Natural Selection
Stabilizing, Directional, Disruptive
descent with modification
the idea that species change over time, give rise to new species, and share a common ancestor. (Darwin and Wallace)
evolutionary fitness
An organism’s ability to survive and reproduce in its environment.
The necessary and sufficient conditions for natural selection to occur:
Variation in the trait
Inheritance of the trait needs to be able to pass down
Differential reproductive success
Differential reproductive success
means individuals with beneficial traits produce more offspring, shaping evolution
How did Darwin’s conception of evolution differ from Lamarck’s?
Darwin believed evolution happens through natural selection, where beneficial traits are passed to offspring.
Lamarck thought organisms acquire traits during life and pass them on, which was later disproven.
genotype
An individual’s genetic makeup.
trait
A feature of an organism’s phenotype. For example, hair color, testosterone levels, wingspan, and physical behaviors.
Inheritance of the Trait
The trait can be passed on from parent to offspring.
Adaptation:
A trait that has been modified over time by natural selection and increases its bearers’ reproductive success.
A hypothesis cannot be:
wrong or false
To be an adaptation, a trait must:
increase the reproductive success of individuals
Provide benefits that outweigh the costs of possessing the trait
Be a product of natural selection
Evolution is BEST defined as a change in ________ in a population over generations.
Allele frequencies
allele
different versions, or forms, of a single gene.
Anthropology consists of which of the following fields of study?
Linguistic Anthropology
Biological Anthropology
Social Anthropology
Archaeology
Human evolution is _____________ and __________________.
biological; cultural
