BISC 110 Chapter Notes -Dna Replication, Chromosome, Gene Duplication

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fuchsiaskunk15

5 Jul 2014

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 110

Professor

Kevin Lam

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Document Summary

If the environment changes, or if the individuals move to a new environment, natural selection may result in adaptation to new conditions (evolution of new species?) Microevolution: change in allele frequencies in population over generations. Three main mechanisms that can cause allele frequency to change = natural selection, genetic drift (chance events) and gene flow (transfer of allele between populations) Only natural selection consistently improves the match between organisms and their environment (adaptation) Genetic variation: differences among individuals in the composition of their genes or other dna segments: genetic variation makes evolution possible. Variation in heritable traits is a prerequisite for evolution: phenotype is the product of an inherited genotype and many environmental influences. Variation within a population: characters that vary within a population may be discrete or quantitative. Discrete characters are determined by single gene locus with different alleles that produce distinct phenotypes: most heritable variation involved quantitative characters, which vary along a continuum within population.

Related Questions

Match the following into these 3 category's: natural selection, genetic drift, gene flow

1. Consistently causes a population to become better adapted to its environment
2, cannot cause a harmful allele to become more common
3. can introduce new allele into a populations gene pool
4. causes allele frequencies to fluctuate rapidly'
5. a result of differential success in reproduction
6 responsible for the founder effect
7. responsible for the bottleneck effect
8., a result of the movement of fertile individuals or their gametes

yellowjackal723

Which statement about evolution by natural selection isfalse?

Natural selection allows organisms with higher fitness toreproduce more successfully.

Natural selection favors those traits that confer higherfitness in the environment.

Natural selection is a random change in characteristics of apopulation over generations.

Evolution by natural selection affects populations oforganisms, not individual organisms.

An organism's fitness depends on its _____.

ability to survive and reproduce

ability to swap genetic material with other organisms

physical size

ability to mutate

population

Consider the heavily armored stickleback fish population thatcolonized the lake. If all the individuals in that population weregenetically identical, what do you predict would happen when theycolonized the freshwater lake?

The population would increase, as it has increased foodresources.

The population would evolve through natural selection to bebetter adapted to its environment.

The population would decrease due to more juvenile fish beingeaten.

No answer text provided.

Which of the following are adaptations?

Thicker beaks on finches that allows them to eat large seeds,when large seeds are the most abundant.

Less armor on stickleback fish in freshwater that allows themto grow faster to avoid predation.

More armor on stickleback fish in the ocean that prevents themfrom being eaten by larger predators.

None of the above.

All of the above.