exam 3 Flashcards
lamarckianism
traits acquired during the life time of an individual were passed on to offspring
darwins theory
natural selection or genetically based variation leads to evolutionary change
charles lylell principles of geology
earth is much older than 6000 yrs old earths geology is formed by slow moving forces
thomas robert malthus
an essay on the principle of population 1798 human population will be limited by factor such as food water some individuals die others survive
favorable variations would tend to be preserved and unfavorable ones to be destroyed
charles darwin
alfred russel wallace
closely related species occupied neighboring geographic areas barriers such as the amazon separated related species
descent with modification
traits vary among individuals individuals with certain traits reproduce and have more offspring
Staph infections
30-40% of healthy people carry staph infection begins with little cut or surgical wound with gets infected staph can be minor (fingernail infection) or ver serious and lead to death -organ failure
high risk of staph
athletes people with weakened immune systems infections of surgical wounds
Antibiotics
chemical (drugs) that kill bacteria or slow their growth by interfering with function of cell structure
history antibiotics
a fungus penicillium can kill bacteria 1928 for decades antibiotics treated bacterial infections and death rate due bacteria dropped resistance started to emerge some staph strains resist every type of treatment
how do bacteria quire resistance
mutation and gene transfer
Mutation
creates new genetic diversity by creating new alleles
what is an allele
variant of a gene
cystic fibrosis is caused by …
a mutation in the CFTR gene cystic fibrosis deletes the CTT-which interferes with gene function
what is a population
group of the same species that live together in the same geographic area
how do populations evolve
a new trait can raise when that trait is favored it is advantageous to have that trait
fitness
how well an individual does -survival and reproduction resulting in offspring
Factors related to fitness:
- survive
- reproduce
- offspring quality
evolution
is the change in allele evolution over time
what happens when a trait is favored (over others)
the alleles that code for those traits increase frequency over time
natural selection
favors some traits over others the population shows adaptation
adaptation
advantageous traits become more common in population over time
evolution by natural selection occurs in populations or individuals ?
populations individual organism do not experience a change in allele frequencies over time therefore individuals don’t evolve
sexual selection
occurs when traits used in attracting mates vary and individuals with certain traits attract the most mates
inbreeding
the mating between relatives is the most intensively studied form of nonrandom mating
consequences of inbreeding
because relatives share a common ancestor individuals that breed with relatives are likely to have the same alleles
how does inbreeding influence evolution
although inbreeding does not directly cause evolution it can speed up the rate of evolutionary change it increases the rte at which natural selection eliminates deleterious alleles from a population
genetic drift
its all about chance random fluctuations in the number of alleles in a pulsation an allele may increase or decrease by chance over time
founder effect
few individuals colonize and establish small isolated populations new population is likely to have different allele frequencies than the source population by chance
population bottle neck
a sudden reduction in the number of (different) alleles in a population
the effects of genetic drift are most pronounced in
small isolated populations
the colonization of beetles on an island that never had those beetles before is an example of
founder effect
the following is false regarding genetic bottle necks
results from a disease that targets individuals that already weak or inferior
what are the consequences of gene flow
serves to homogenize (make the same) all frequencies between populations