The Evolution of Populations Flashcards
What is microevolution?
Changes within a species
What is macroevolution?
Changes to a new species
What’s the story about the medium ground finch population on the island of Daphne Major in the Galápagos Islands?
1977- drought
The birds with deeper bigger harder beaks survived because they could carry more water and break more seeds and nuts since harder seeds were the ones that survived
This is microevolution
What is phenotypic variation
Different in what we see
What is genetic variation?
Everything is genetically different
Does genetic variation necessarily manifest itself as outwardly observable phenotypic variation?
No; heterozygous verses homozygous dominate
Does phenotypic variation have to result from genetic variation?
No we can have environmental reasons
What is the deal with moth caterpillars?
Camouflage is based on what they eat
How does mutation create new alleles?
Changes in the DNA; change in nucleotide pair; changes the codon in mRNA
This gives a new amino acid which could cause a disease or make cells collapse
Mutation rates tend to be low, so how does rapid reproduction affect the spread of new alleles in a population?
Things that spread are generally beneficial mutations
Again, mutation rates tend to be low, so how does sexual reproduction affect the spread of new alleles in a population?
Creates new genotype
How do we define “population”?
Individuals of the same species generally in the same place at the same time
What is a populations gene pool?
All the genes and alleles that you have in that species or population
What’s the deal if only one allele exists for a particular locus
If there is only one allele, then we are homozygous
What’s the deal if two or more alleles exist for a particular locus
They are either homozygous or heterozygous
What us allele frequency
How many people posses the allele in the population
What does it mean for a population to be at Hardy-Weinberg equilibrium?
Not evolving
What are the conditions for Hardy-Weinberg equilibrium?
No mutations Random mating No natural selection Extremely large pop size No gene flow
What exactly is natural selection?
Whatever lives long enough to reproduce does
How can natural selection alter allele frequencies in a population
The things that do survive have certain phenotypes that allow them to survive
What is genetic drift?
Change in frequency of a gene variant in a population due to random sampling
What is founder effect?
A species found in a new population where they haven’t been before
What is the bottleneck effect? How does this differ from the founder effect?
Population decimates
If it is founder they can still have an original large population. in bottle neck the population is smaller
What is gene flow?
One way Migration
