Genetic Drift
Some event happens to decrease the population size, few survivors make up the new gene pool
Bottleneck Effect
The process where biologically fit organisms survive and reproduce at higher rates than less biologically fit organisms in a given environment, leading to a change in allele frequencies or phenotypes of the population.
Natural Selection
Large changes in a population’s traits over a long period of time, this can lead to speciation.
Macroevolution
If 50 individuals in a population of 100 have blue alleles, what is the blue allele frequency?
50/100 * 100 = 50%
What are four ways that we have seen populations evolve?
Natural Selection - Frogs, Fish, Mice, Flowers
Artificial Selection - Any domestic animal
Founder Effect - Tortoises and Finches of Galapagos
Bottleneck Effect - Beak size of finch in the Galapagos
A portion of a population moves to a new environment and is separated from the original population.
Founder Effect
Shifting a population’s traits towards both extreme phenotypes.
Disruptive Selection
A change in a population's trait over time.
Evolution
The formation of a new species from an existing population.
Speciation
In the case study of the prickly pear, the javelina, and the larva. The what type of natural selection did the number of prickly pear spines show us?
If they were too dense there would be no seed dispersal and if they were not dense enough the larva would kill the plant.
Stabilizing
The total variety of alleles/genes in a population.
Gene Pool
Shifting a population’s traits towards one of the extreme phenotypes.
Directional Selection
The frequency of an allele in a population.
Allele Frequency
What type of evolution results in speciation?
Macroevolution
What type of natural selection was shown in the pepper moths and industrial revolution?
Camouflage moths were eaten at lower rates than non-camouflage moths.
Directional
The random change in allele frequencies that occurs in small populations.
Genetic Drift
Shifting a population’s traits towards the average phenotype
Stabilizing Selection
Small changes in a population’s traits over a short period of time, this does not lead to speciation.
Microevolution
Using your understanding of genetics and evolution justify the existence of deadly recessive traits.
A deadly recessive trait is only deadly if an organism has two copies of it. Therefore, any heterozygous organism could have a copy of the dominant non-deadly trait while also being a carrier for the recessive deadly trait.
What type of natural selection was observed when sardine fishing?
Too large didn't fit in the cans, too small were not desirable to eat.
Disruptive
Why are Darwin's finches a good example of the bottleneck effect?
Small island population that had its size decreased by a drought.
The process where humans choose which organisms to breed together to produce desired traits in future generations.
Artificial Selection
The ability to survive and reproduce.
Biological Fitness or Fitness
At what point do we consider two populations of once similar organisms two individual species?
When they are not able to reproduce or stop reproducing with one another all together.
Ex. Birds of Paradise video
What type of natural selection was being shown when the mice were blending in with different backgrounds?
Directional