The+Drifters


 * Group members**
 * Vidya Baji
 * Almira Khaliq
 * Aicha Jaowad
 * Justina Poh
 * Kholeka Ndlovu

We will be sampling along two interrupted belt transects and will be collecting data from all 2 different habitats (Shrubland and hilly grassland). Three samples will be collected from the same habitat at 2 different regions.The site in which we collect our samples will be at least 20m apart to ensure that each population is independent. Also, we will be collecting a sample size of 20 snails randomly at each site to record the types of snails present. To reduce human error, we will establish a standard within our group before sampling on the variables such as snail colour, types, number of bands, size, etc. The results obtained from all sites will be compiled and compared, which will allow us to understand the frequency of polymorphism in the habitat.
 * Method**


 * Advantages **
 * An interrupted transect allows us to collect data from a range of habitats so that we can compare the contribution ofenvironment to the polymorphism of the snails.
 * Taking samples from two different transects means that we can compare t he results obtainedfrom the habitats on one transect with the other to see any co-relation, or if the results are due to selection or genetic drift. If selection is the cause, we would expect to see similar results from the same type of habitats on both transects.
 * Sample size is relatively large to reduce sampling error.


 * Disadvantages **
 * Time restrictions mean we can only take a total of 6 samples. Thus, our result may not show a true representation of the types of snails present on that particular type of habitat and the statistics we receive may be due to chance.

There will be no difference in the distribution of coloured snails between the different habitats. Explanation: The type of snails present in one type of habitat on one transect may not be present or as dominant on the same type of habitat from the other transect. This might mean that the type of snails present on that habitat is purely due to genetic drift and not due to selection.
 * Null Hypothesis **

There is a difference in the distribution of coloured snails between the different habitats. A small frequency of polymorphism will be observed if more than one type of snail is present in the same type of habitat on both transects.
 * Alternative Hypothesis **

As some of the results are less than 3; we will combine results of Yellow snails with Green snails and Orange with Red snails. Expected = 14 Chi-sq = 0.286 || 9 Expected = 44/3 Chi-sq = 2.189 || 15 Expected = 11 1/3 Chi-sq = 1.186 || 40 || Expected = 14 Chi-sq = 1.786 || 15 Expected = 44/3 Chi-sq = 0.007576 || 16 Expected = 11 1/3 Chi-sq = 98/51 || 40 || Expected = 14 Chi-sq = 9/14 || 20 Expected = 44/3 Chi-sq = 64/33 || 3 Expected = 11 1/3 Chi-sq = 625/102 || 40 || X^2 = 16.086 (3 d.p.) Degree of Freedom = 4 P-value = 0.00290591
 * Results:**
 * || B || G || O || R || Y || Row Total ||
 * Population 1 (Bush) || 16 || 8 || 6 || 9 || 1 || 40 ||
 * Population 2 (Grass) || 9 || 10 || 2 || 14 || 5 || 40 ||
 * Population 3 (Wood) || 17 || 20 || 3 || 0 || 0 || 40 ||
 * Column Total || 42 || 38 || 11 || 23 || 6 || 120 ||
 * || B || G + Y || O + R || Total ||
 * Population 1 (Bush) || 16
 * Population 2 (Grass) || 9
 * Population 3 (Wood) || 17
 * || 42 || 44 || 33 || 120 ||

Therefore, there is a 0.00290591 chance that we would get the results if the null hypothesis is true.

Critical value (2-tailed) = 9.49 Our results are significant as the Chi-square value is greater than the critical value.

__**Introduction**__

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Capaea nemoralis is a kind of cross hermaphrodites which presents the most polymorphic traits among the European fauna. The theory of polymorphism can be easily explained using snails as they are easy to sample; with distinct features for differentiation of their subtypes since Capaea nemoralis shows difference in shell background colour, number of bands and several other features. <range type="comment" id="380969748_4">Their habitats are small compared to the human population </range id="380969748_4">and long-term monitoring can be conducted <range type="comment" id="380969748_5">easily as snails travel about 20metres</range id="380969748_5"> in their lifetime. The habitat that we sampled from was Pulpit Hill in Buckinghamshire, it has a high <range type="comment" id="380969748_6">abundance of chalk in its soil resulting in a high number of snails due to the fact that snails benefit from chalk to build their shells.</range id="380969748_6"> =====

=
To understand the frequency of polymorphism in the habitat, we set up a sampling regime where we will be sampling along two interrupted belt transects. Data will be collected from 2 different habitats – shrub-land and hilly grassland and samples will be do ne in triplicates in each habitat at 2 different transects to ensure replication. The site in which we collect our samples will be at least 20m apart to <range type="comment" id="380969748_7">ensure that each population is independent</range id="380969748_7">. Also, a sample size of 20 snails <range type="comment" id="380969748_8">will be collected randomly</range id="380969748_8"> at each site to e<range type="comment" id="380969748_9">nsure that our results are significant</range id="380969748_9">. To reduce human error, we will establish <range type="comment" id="380969748_10">a standard within our group </range id="380969748_10">before sampling on the variables such as snail colour, types, number of bands, size, etc. The results obtained from all sites will be compiled and compared, of which will allow us to understand the frequency of polymorphism in each habitat.=====

Our proposed hypothesis is that there is a difference in the types of snails between different habitats. A small frequency of polymorphism will be observed if more than one type of snail is present in the same type of habitat on both transects. Thus, our null hypothesis<range type="comment" id="380969748_11"> is that there will be no difference in the type of snails between the different habitat</range id="380969748_11">s. This might mean that the type of snails present on that habitat is purely due<range type="comment" id="380969748_12"> to genetic drift and not due to selection.</range id="380969748_12">