Evolution
What is the definition of evolution?
A change in alleles in a population over time
Who was the person who published the "origin of species" after his voyage aboard the HMS Beagle?
Charles Darwin
What determines if two organisms are part of the same species?
What is the main source of genetic variation?
Small Mutations resulting in slight changes to phenotypes
What is the equation for allele frequency?
P + q = 1
What does biological fitness mean?
To survive and reproduce
Where did Darwin travel to?
Galapagos Islands
What causes new species to form?
Reproductive Isolation
What is genetic drift?
Random occurrences that result in the change of the frequency of alleles
What is the equation for the genotypes of a population in HW-eq?
P^2 + 2Pq + q^2 = 1
What were hutton and lyells contributions to evolutionary theory?
Hutton = Deep time
Lyell = uniformitarianism
both = where over a long period of time small geologic changes in the past resulted in vast structures we see today
What was Lamarck's theory of evolution? Why was this false?
- Parents can pass effort onto their offspring (giraffe growing necks longer).
- Most organisms cannot change their genetics.
What are the four pre-zygotic barriers? (covered in this class)
Temporal, Behavioral, Ecological, Mechanical
What is a genetic bottleneck? Give an example and how it influences a community
When an event causes a large population to become a much smaller section of the whole and therefore changes the percentage of allele relative to the original population
What does 2pq mean?
What is the difference between a homologous structure and an analogous structure?
Homologous = similar bone structure but different function (forearm of human vs. bat)
Analogous = different bone structure but similar function (fin of a dolphin vs. shark)
How have we artificially selected traits in dogs?
Pugs = breed all the small nosed dogs and don't breed the ones with long noses then each generation get shorter and shorter noses
What are the three post-zygotic barriers?
- Hybrid Inviability
- Hybrid Infertility
- Hybrid Breakdown
What is the main method of genetic variation in most humans today other than mutations?
Recombination of genes during meiosis
What is the point of HW-eq
To provide a null hypothesis for evolution
Directional selection favors one specific trait whereas disruptive favors two extremes. Stabilizing is often the end result of both previous selection types as a population optimizes toward their niche.
What were Darwin's 3 observations on his voyage?
- unrelated organisms possessed similar structures that lived in similar habitats
- related organisms possessed different structures if they lived in different habitats
- fossils of extinct species harbored similar traits to their modern counterparts in the same area
Using what you know about reproductive isolation and evolution. How are more species generated?
When a population is isolated over a long period of time. Each population will change over time based on their location and with enough genetic separation the differences can be so accumulated that the populations can no longer mate based on their inability procreate and therefore the population becomes two species.
More biodiversity = more variation in traits = more change that populations will be advantageous when faced with a selective pressure so they can survive and reproduce more
What are the 5 conditions for a population to be in HW-Eq.
Large Pop, Random Mating, No selection, No mutation, No gene flow