EVOLUTION Flashcards
Define population.
What are the 4 main parts of Darwin’s reasoning for natural selection?
Overproduction
Overproduction of offspring
Most organisms have more offspring that the resources of that particular environment can support
Genetic variation
Genetic variation among individuals
Within a population, individuals have unique characteristics. These can include:
Physical traits
Behaviors
biochemistry
Struggle to survive
In any environment, an organism’s needs must be met in order for them to survive and reproduce. These can include:
Food
Shelter
Mates
Because resources are limited, members of a population will be in competition with each other for these resources
Differential reproduction or fitness
AKA survival of the fittest
Those organisms best suited to their environment (best adapted) will survive to reproduce. So, over time there will be a change in the inheritable characteristics of the species
fitness:
Success in passing on genes to offspring relative to other members on a population in a particular environment
What did most scientists of Darwin’s time believe in regards to species of organisms on Earth.
In the 18th century, most scientists believed that all species were permanent and unchanging
Most believed the earth was only thousands (and not billions) of years old. All species of animals were created by God at the same time and coexisted to the planet (creationism)
Define adaptation.
traits that increase the fitness of individuals
Generally true as a result of Natural Selection. However, if a sudden environmental change occurs - then the ‘adaptation’ may actually decrease the organism’s fitness
Adaptation is NOT the same as Acclimatization
Define a homologous structure. Give an example.
Natural selection is:
Darwin’s proposed theory - natural selection is the mechanism for descent with modification. Darwin thought carefully about the forces that could cause changes in organisms overtime
Who proposed the idea of acquired characteristics?
What was the major idea in Darwin’s book?
- List three types of evidence for evolution.
What convergent evolution?
How does evolution occur?
Give one example of a vestigial structure in a human.
Define an analogous structure. Give an example.
What is divergent evolution?
Define a vestigial structure.
What are three different types of adaptations?
DIRECTIONAL, DISRUPTIVE, STABILIZING:
DIRECTIONAL - favors traits at one end of the range of variations
Example: peppered moths of England
This is considered “industrial melanism”, as it is a color change in response to pollution
DISRUPTIVE - favors individuals at both extremes against the middle and produces two more distinct phenotypes (physical appearance)
Example: African Swallowtail
Two different phenotypes developed: both resemble poisonous varieties
Example: mice
There are 3 varieties of mice: black, white, and gray (in-between)
The black and white camouflaged better than the gray one, meaning the extremes (black and white) were favored
STABILIZING - favors individuals who have phenotypes near the mean rather than at the extremes
Example: human birth weights
Who is George Cuvier, and what are his main ideas?
Who is Charles Lyell, and what are his main ideas?
- List and define the types of natural selection.
Who is Jean-Baptiste Lamarck, and what are his main ideas?
Supported the idea that populations of organisms change over time
Lamarck proposed that individuals could ACQUIRE traits during their lifetimes as a result of behavior and then pass these traits to offspring. This idea is called the inheritance of acquired characteristics
What is coevolution?
what is evolution
The development of new organisms from preexisting types of organisms
Also defined as:
A heritable change in the characteristic within a population for one generation to the next
A change in allele frequencies over time (this relates to the genetics of evolution)
Define immigration and emigration, in relation to genetics.
Define adaptive radiation.
Define genetic drift. What types of populations are most susceptible to genetic drift?
