Evolution :D
What are some examples of artificial selection?
. Cauliflower, broccoli, kale, and brussel sprouts come from wild mustard plant . The various dog breeds that originated from the wolf
What are the main points of Darwin's origin of species? (Be able to explain Darwin's diagram)
1) Variation exists in natural populations 2) More offspring are born than what the environment is able to support --> struggle to survive: competition 3) Differential survival - beneficial charcteristics for survival; adaptations = (ex. camouflage) --> will become more common in population 4) Differential reproduction - succeesful organisms live longer --> as adaptations become more common in population --> cahnes gene frequencies within population's gene pool --> emergence of new species
Hardy Weinberg
1) determine allele frequency in a population 2) estimate frequency of heterozygotes in a population 3) identify forces that cause evolution
What is diversifying selection?
A form of natural selection in which extreme values for a trait are favored over intermediate values
What is stabilizing selection?
A form of natural selection wherein individuals with moderate or average phenotypes are more likely to survive and reproduce
What is natural selection? What is an example of natural selection?
Adapting to fit the environment and increasing survival rate A population of mice with tan and black mice see a higher survival rate for black mice because they blend with the environment
What are the two ways speciation can occur?
Allopatric and sympatric
What does allele mean?
Alternative version of genes and are represented by letters Is a variant form of a gene (piece of DNA) at a single locus
What is mutation? What is an example of mutation?
Change in DNA sequence Hemophilia
What is genetic drift? What is an example of genetic drift?
Change in frequency of a gene variant in a population --> (not caused by environmental/ adaptive pressure) A population of rabbits with white and brown fur that due to genetic drift, rabbits with white fur are eliminated
What does heterozygous mean?
Different combination of DNA; two different alleles
What is artificial selection?
Evolutionary process in which humans consciously select for or against particular features in organisms
What is directional selection?
Form of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction, usually extreme phenotypes
What is allopatric speciation?
Geographic isolation which results in speciation
What is an example of stabilizing selection?
In a population of birds, the phenotype for a intermediate shade of feathers is favored
What is an example of diversifying selection?
In a population of birds, the phenotype for the extreme light and dark colored feathers is favored
What is an example of directional selection?
In a population of birds, the phenotype of light colored feathers is favored
What does adaptation mean?
Inherited traits that enhance an organisms ability to survive and reproduce
What are the driving forces for gene variability?
Mutation and gene flow
What are the four mechanisms of evolutionary change?
Mutation, gene flow, genetic drift, natural selection
What does natural selection mean?
Nature picks which traits are passed down
What is an example of bottleneck effect?
Northern elephant seals were hunted to almost extinction, approx only 20 left
What is the bottleneck effect?
Occurs after an event greatly reduces the size of a population leaving a small, random assortment of individuals; a lack of genetic variation
What is an example of founder's effect?
Polydatyly wich is commonly found among the Old Order Amish of Pennsylvania
What does fitness mean?
Reproductive success and how well an organism is adapted to environment
What does homozygous mean?
Same combination of DNA; the same alleles
What does speciation mean?
The process by which two populations of the same species become so different that they can no longer interbreed New species formed
What is sympatric speciation?
The process through which new species evolve from a single ancestral species while inhabiting the same geographic region
What is the founder effect?
The reduced genetic diversity that results when a small population is descended from a larger population
What is gene flow? What is an example of gene flow?
Transferring of alleles of genes from one population to another Geese from one population interbreeding with another population
What is an example of microevolution?
finches beaks; resistance to pesticide