Module 14 - Evolution Flashcards
What is natural selection?
Theory of evolution developed by Darwin, the survival of the fittest.
Who was Charles Darwin?
Scientist who developed the theory of evolution and natural selection.
Who was Thomas Malthus?
An economist who introduced the idea of natural selection in terms of humans.
What are the four principles of natural selection? *
Excess reproduction (producing way more seeds than can actually be sustained)
Variations (differences in traits between a group of organisms)
Inheritance (organisms get traits from their parents)
The advantages of specific traits in an environment (organisms with the best traits will survive longer, reproduce, and eventually that trait will be the main one in that species)
What is evolution?
The change in species over time
What is a derived trait? *
A new feature that had not appeared in common ancestors
What is an ancestral trait? *
More primitive characteristic that appeared in common ancestors
What is an embryo?
An early, pre-birth stage of an organism’s development
What is a homologous structure? *
Anatomical structures inherited from a common ancestor
What are vestigial structures? *
A kind of homologous structure that has either a reduced function or no function in an adult organism. They are functional in related organisms or were functional in an ancestor.
What is an analogous structures? *
Structures that can be used for the same purpose and can be superficially similar in construction, but are not inherited from a common ancestor
What is geographic distribution?
The idea that organisms are more similar to other organisms in their area than organisms across the planet, suggesting that the plants and/or animals in a geographic location share a closer ancestor than plants and/or animals in a different part of the Earth.
What is biogeography?
The study of the distribution of plants and animals around the world
What are the five categories that offer evidence for evolution? *
The fossil record, comparative anatomy, comparative embryology, comparative biochemistry, and geographic distribution
What is fitness?
A measure of the relative contribution that an individual trait makes to the next generation
What is the difference between camouflage and mimicry?
Camouflage makes an organism difficult for predators to see by blending in with their environment. Mimicry is an adaptation where one species starts to look like another, more harmful species so that predators are less likely to attack them.
What is the Hardy-Weinberg principle? *
When allelic frequencies remain constant, a population is in genetic equilibrium. (proportions of genotypes)
What five conditions does a population need to meet to be in genetic equilibrium? *
No genetic drift
No gene flow (no immigration or emigration)
No mutation
Mating must be random
No natural selection
What is genetic drift?
Random change in allelic frequencies in a population
What is the founder effect?
Random effect that can occur when a small population settles in an area separated from the rest of the population and interbreeds, producing unique allelic variations. (changing the allelic frequencies.)
What is a bottleneck?
Process in which a large population declines in number, then rebounds. (changing the allelic frequencies)
What is stabilizing selection *
Most common form of natural selection in which organisms with extreme expressions of a trait are removed. (against both extremes)
What is directional selection? *
Shift of a population toward an extreme version of a beneficial trait. (against one extreme, towards the other)
What is disruptive selection? *
Process in which individuals with average traits are removed, creating two populations with extreme traits. (Against the mean)
