Charles Darwin is famous for his book, The Origin of Species, where he proposed that evolutionary change in populations is due to natural selection. His idea was that of survival of the fittest. In other words, the species with superior traits would have more of a likelihood to live, and then breed more offspring. Slowly, more and more of the species with the superior traits will survive and multiply. But what is it that gives these species the better survival trait, and allows evolution to occur? The answer is, genetic variation. Each individual has different genotypes that make up their structure and infrastructure. This includes physical features, behaviors, and even the abilities of an individual on the molecular and cellular …show more content…
First, each individual tasted a PTC paper and a control paper for comparison, and pooled together our results. If the the individual could taste the paper, they inferred that they were either TT (homozygous taster) or Tt (heterozygous taster), and if they could not taste the paper, they knew they were tt (homozygous non-taster). Next, we extracted DNA from our cheek epithelial cells with cotton swabs. We were able to do this by inserting the end of the swab into a DNA extraction solution, followed by incubation and vortex, as following: vortex for 10 seconds, incubate for 1 minute at 65˚C, vortex for 15 seconds, incubate for 2 minute at 98˚C, vortex 15 seconds, place DNA sample into cup of ice. Once we had our DNA collected, it was time to amplify our desired loci by PCR- polymerase chain reactions. PCR allows us to take a small amount of DNA, and multiply it for easier analysis. The PCR reaction for each locus was set up by pipetting 20ul primer mix (L for LCT and P T for TAS2R38) into 0.2ml of the PCR Master Mix (Taq DNA polymerase, four dNTPs, and required buffer and salts for polymerase to function). Taq polymerase is part of the mix because it is thermostable, which is appropriate considering our DNA strands need to undergo extreme temperatures to completely separate their complementary strands. The PCR primer is essential for targeting the desired loci and restriction enzymes. Next, each team member pipetted 5ul of their cheek cell DNA extract into their own PCR/primer mixture. After centrifuging the PCRs for around 5 seconds, we put them through the following 40 cycles: 5 minute at 95˚ (denaturation–separates DNA strands), 30 seconds at 95˚C (annealing– bonding of DNA strands), 30 seconds at 72˚C (polymerization–synthesis of new DNA), and 5 minutes at 72˚C (completes synthesis) (Leicht and McAllister 2015). Finally, the PCR reactions