Mathematician+Physician=Hardy-Weinberg Equation

To expand on last week's lesson on evolution, this week in AP Biology we learned how to track evolution. There are a few things you have to know before you can actually track evolution though. One of them is a population, which is a local group of interbreeding individuals. Unlike, most previous ideas evolution does not occur through an individual, but a population. Another thing is a gene pool which is the collection of alleles in a population. To add on to that you need to know what allele frequency, which is how common the specific allele is in that population. A big thing to know is a slightly new and updated definition of evolution. Evolution can now be defined as a change in allele frequencies in a population. This leads us into how to measure evolution. 

To measure evolution you need to know the Hardy-Weinberg Equation, and to use this equation the population must be in Hardy-Weinberg Equilibrium. This means there must be a large population, no migration, no mutations, random mating, and no natural selection. Which is pretty much a nonexistent population. So, all of this is hypothetical.  Now to look at the Hardy-Weinberg Equation.
                                                               p+q=1
p= frequency of dominant allele
q= frequency of recessive allele
Both of the frequencies must add together to equal one. To find the frequency of homozygous dominant, heterozygous, and homozygous recessive you need to use this equation:
                                                            p²+2pq+q²=1

p^{2= the frequency of homozygous dominant}

2pq= the frequency of heterozygous

q²= the frequency of homozygous recessive

These two equations serve as a null hypothesis to measure if forces are actually acting on a population. 

From the Ape to Humans... Evolution

This week in AP biology we went over evolution and learned that it's not really about ape to humans and all that. Evolution can be described as genetic changes in a population that happen over time. There are 8 mechanisms of evolution. 

The first one is natural selection. The first thing we think about natural selection is Charles Darwin , the Galápagos Islands, and only the strong survive. While the first two are correct, the third one is incorrect. Instead of only the strong survive it is the most adaptable survive. Three things are really important to natural selection. They are variation of genes in population, the variations to be heritable, and differential reproductive success. An example of natural selection would be a green caterpillar and a blue caterpillar on a green leaf the green caterpillar will blend in while the blue one will be easier for predators to spot. Therefore the green caterpillar will survive to reproduce more than the blue caterpillar will. 

Mutations or any change in the DNA is also a mechanism. Not all mutations are relevant to evolution. Only the mutations that will occur in gamete or sex cells can lead to evolution. 

The third mechanism is recombination. Recombination is mostly about crossing over that occurs during meiosis. The new gene combinations can be helpful and harmful to the organism. 

Gene Flow or migration is the fourth mechanism. Gene flow is one an organism leaves and takes their traits with them. When an organism leaves one population and goes to the other and reproduces their it takes its genes that the population had not been introduced to yet and includes them in the gene pool of the population. 

Genetic drift is chance changes in a population. It is entirely random and doesn't necessarily lead to the best or most adaptable organisms surviving. 

Artificial selection is the sixth mechanism of evolution. It is called this because instead of the organism choosing who to mate with humans do. This is very common in livestock animals. Breeders breed the biggest and best animals to wi the shows. 

Non- Random mating or sexual selection is the fact that not all individuals have the same chance of mating. Not always a good thing as it can lead to organism being more visual sexual selection happens in peacocks, some birds, and flys. 

The last mechanism is reproductive isolation.  Reproductive isolation occurs when a species is separated and then become two different species. This happened on the Galápagos Islands. Most cormorants are able to fly except for a type of cormorant that is found on the Galápagos Islands.