McLean+McCoy

McLean McCoy

 **__ Evolutionary Genetics Snail Trip Introduction __** 

Polymorphism is a term used to describe the different no, the existence  visible no ﻿ phenotypes of a gene in a population of the same species. This occurs when many alleles of a single gene are present within a panmictic doesn't need to be panmictic population that occupies the same habitat doesn't need to be in the same habitat at the same time. Each phenotypic variant must be discontinuous and make up at least 1% of the population in order to confirm that it is not merely a mutation old fashioned definition. One species affected by affected or has? polymorphism is //Cepaea nemoralis//, a __ snail __ which takes on either a pink, yellow or brown colour, and has between zero and five bands. These are found on grass chalk-land, only? such as Pulpit Hill reserve, near Monk’s Riseborough These snails are an appropriate wrong word study specimen species as they are slow moving, therefore easy to collect scale of differentiation? , and prominently display their phenotypic variations variation is singular. As well as this, they form small sub populations within close proximity to each other what does that mean? . This allows the data of many populations to be collected, increasing the validity of the experiment explain why. The effects of mutation, genetic drift, selection or gene flow can then be observed how? , if there are any. In order to decipher whether the phenotypes of C. nemoralis meta-populations vary in different environments imprecise, we will take samples from at least four sites. Sites one and two will be geographically similar as will sites three and four, though the latter two will be dissimilar to the first two why this design. Each site will be approximately 20m in diameter, within which we will record the different variants we come across. This will allow us to see whether similar phenotypic traits are produced in similar environments. We therefore propose that there will be different polymorphic variants the population is polymorphic, not the variants prominent in different types of environments what about telling if its drift or seln. Finding similar combinations of polymorphs at two different, yet geographically similar, sites would support our hypothesis. However, if random combinations of polymorphs were found at every site, our hypothesis would be disproved vage and logic not clear.