por Michelle Otis 11 anos atrás
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Key:
Red: Exam 1
Yellow: Exam 2
Blue: Exam 3
I expanded the most on the areas I needed the most review.
Tuberculosis
Small Pox
Flu
Water
Air Quality
Lliving Space
Hormonal control
Pheromone stations
Pheromone traps
Reproductive control
Release Sterile males
Chemical Sterilants
Release incompatible pest stains
Control by another organism
Parasites
Predators
Pathogens
Unsuitable or destroyed habitat (-)
Adequate Food Supply (+)
Specialized Niche(-)
Generalized Niche (+)
Low reproductive rate (-)
High reproductive Rate (+)
Competitive Exclusion Principle: When similiar species that compete for the same limiting resources cannot coexist in the same environment (if their niches are identical.) One will use the resources more efficiently and thus reproduce more rapidly. Even a slight reproductive advantage will eventually lead to local elimination of the inferior competitor.
OR a species can evolve through natural selction to use a different set of resources/niche to avoid competition and coexist. (each species K value is lower)
Not all species have the same carrying capacity because every species interacts with the environment in a different way.
Adaptive radiation is pretty similiar to divergent evolution the only difference is that the radiation happens all at the same time.
Divergent Evolution occurs with character displacement over time.
Character displacement refers to the phenomenon where differences amoung similiar species whose distributions overlap geographicallyare accentuated in regions where the species co-occur to reduce competition.
However, Sometimes (1% of the time) two species are able to mate and produce a hybrid species.
This can create a hybrid that is considered Polyploidy.
Can also be cause by a nondisjunction of chromosomes of one parents chromosome in their gamete thereby producing a polyploidy when combined with a normal gamete.
Can be caused by an unreduced gamete and a normal gamete coming together to form a triploid gamete or a new species.
Allele frequencies change in the direction of the donor /source population due to migration.
Therefore: Migration rate is the number of immigrants divided by the new total population.
If we know the migration rate, we can find out migration rate of alleles.
Q(after immigration)= q ((the recessive allele frequency)of immigrants) M(migration rate)+q (residents)
To find P just subtract the new q value from 1.
Because p+q=1
Genetic Bottleneck Effect: Random changes in allele frequencies in a population due to a dramatic reduction in population size.
Sampling error is the random deviation from the expected value determined by chance
Therefore, the larger the population/ sample size the smaller the deviation on average.
Founder Effect: Random changes in allele frequencies in a population during colonization.
It's basically the colonizer's chance of deviation from the gene frequencies of their source population.
Mutations are where new alleles come from
Mutations are the ultimate source of genetic variation.
Selection Differential: The difference between the mean of the population and the mean of individuals selected to be the parents of the next generation.
Therefore: Selection Differential= Mean(selected)-Mean (whole)= Mean intensity of selection.
Selection as defined by Dr. Levin: Differential reproduction amoung differing phenotypes in a population.
Selection is basically the only form that produces adaptive evolutionary changes for a population. It is the only way for a populaiton to improve.
There are many different kinds of selction.
Artificial Selection: Modification of a species by human intervention so that certain desirable traits are represented in successive generations.
Influenced by the heritability of the trait and the pressure/ force that the breeder uses.
Stabilizing Selection: Genetic diversity decreases as the population stabilizes on a particular trait, the intermediate is favored.
Disruptive Selection: changes in population genetics in which extreme values for a trait are favored over intermediate values.
Directional Selection: When a single phenotype is favored causing allele frequency to continually shift in one direction.
Environmentally Dependent
We get one chromosome set from each of our parents.
This is made possible through Meiosis which is a 2 stage type of cell division in sexually reproducing cells that results in half the chromosome number than the parent.
Sometimes there are alterations in the chromosome number that cause genetic disorders like Down Syndrome (trisomy 21.)
Meitoic disjunction is when members of a pair of homologous chromosomes do not separate during Meiosis I or sister chromatids fail to separate during meiosis II.
Creates Monomy
Creates Trisomy
Dihybrid Cross: crosses between 2 loci that are both heterozygous.
Monozygotic Twins: Share 100% of their genes.
Dizygotic twins: share 50% of their genes.
Monohybrid cross: crosses between genotypes with one locus that are heter- ozygous.
Both crosses give rise to a charactersitic or phenotype
Quantitative traits: refer to the phenotypes that vary in degree because of polygenic effects ans their environment. Theycan be measured like body weight, IQ etc.
Therefore, genotype and the environment effect phenotype.
The heritability of a trait is the proportion of the phenotypic variation that is genetically based. (range values: 0-1)
1: All differences are genetically controlled.
0: All differences are environmentally controlled.
Meiosis guarantees the continuity of genetic information from one generation to another.
Additionally, humans have 2 sex chromosomes
Male: XY
Female: XX
