Diversity Flashcards
what is genetic diversity?
variety of alleles within a species
what is a population?
a group of individuals of the same species which live in the same place and can interbreed
What is a species?
members that can breed to produce fertile offspring
How can a DNA mutation be helpful?
A new allele might give an animal an advantage over other individuals
the animal is more likely to gain resources and live longer so it will have a better chance of breeding successfully and producing more offspring
the individuals that reproduce will pass on the allele to their offspring
over many generations the individuals with the advantageous allele will increase in frequency
What is directional selection?
when environmental conditions change
some individuals have a phenotype which is better suited to the change
they are more likely to survive and breed
the mean will shift towards these individuals
give an example of directional selection and explain how it works
A mutation occured in bacteria that gave it antibiotic resistance
the antibiotic was being used and the bacteria survived
it divided by binary fission and produced more resistant bacteria
the frequency of the resistance allele increased
the curve shifts because a greater number of individuals have the resistance allele
what is stabilizing selection?
if the conditions are stable
the individuals closer to the mean will increase
the ones at the extremes will die out
the curve gets narrower
give an example of stabilizing selection and explain why
babies that are too heavy have a hard time passing through the birth canal and infant mortality will increase.
babies that are too light are not favored either and the mortality rate is higher for them too
average weight babies have a lower mortality rate
the curve gets narrower and the spread of individuals gets narrower
What does natural selection do?
create species which are better adapted
anatomically
physically
behaviorally
How are species identified?
by a binomial made up of a generic name and a specific name
genus and species
What are the taxa?
Kingdom Phylum Class Order Family Genus Species
how is phylogenic classification done?
1) based on evolutionary relationships between organisms and ancestors
2) classifies species into groups using shared features from ancestors
3) arranges groups into hierarchies with no overlapping
What is species diversity?
number of different species within one community
what is genetic diversity?
variety of genes posessed by the individuals that makeup the species
what is species richness?
number of different species in an area at a given time
