Gabriela Rivera BIOL 200 LAB DISCUSSION QUESTIONS 1. What is the period of time over which the coat color adaptation has occurred? 1. Around a thousand years for the mutation for the mice living in this habitat was observed, but technically the change could be happened sooner than this, even 100 years based on the math. 2. What is the selective pressure responsible for driving the coat color adaptation? 1. Change in color driven by predators weeding out the mice that don’t match their background. A light colored mouse living in dark rock died out, while those that had darker colored fur survived in the same conditions. 3. What is the evidence that coat color is a heritable trait? (has a genetic basis) 1. Fur controlled by many genes. The difference in these mice boiled down to a difference in four chemical letters. Gene controls amount of dark pigment, a mutation gives it a darker fur. Hundreds of thousands of mice are born in any given year, so the mice that are black have enough of an advantage (even 5%) allows for more reproduction from that phenotype of mouse, which results in a quicker change in overall population. 4. Black coat color in the population of mice studied is the result of a mutation in a gene called Mc1R. Populations of predominantly black mice have been discovered on other, geographically distant lava flows. Mutations in genes other thanMc1R have been identified as the cause of black fur in many of these populations. Explain how these observations support the idea that evolution is not random, but the mutations that make evolution possible are. 1. Mutations come out at random in our DNA. Every new organism comes with their own individual mutations in their genetic code, which supports that mutations are random. Natural Selection demonstrates that those with favorable characteristics, which may be produced with mutations, tend to survive more than those who kept their fur color light. So, under very similar conditions, these dark furred mice were favored as they possessed very similar characteristics, and were able to survive, regardless of how they came about to getting that mutation to change their phenotype.
