1. Asaad Khattab
TA- Shreyas Joshi
BIO 303—004
2/19/2014
Cepaea Nemoralis’s Variation
Based on Number of Bands and Swirls
Introduction
Groove snails, Cepaea Nemoralis, are land snails that common throughout the country, Europe. Five
types of groove snails located from different areas of Lexington were examined and observed in the lab.
The snails were from Virginia Ave, Winchester and De Roode. Some were examined by the weight,
vertical axis of shells, number of band, number of swirls, color, size, and striation.
How were the variation different from one another? The variations were different based on what was
recorded in the lab which was the stripes (number of bands) and the number swirls.
Methods and Statistics
The groove snail’s variation that were measured were the number of bands and number of swirls.
Starting out with the Virginia Avenue samples, we counted the exact number of bands and the number
of swirls.These traits measured were easy to distinguish between them The broken shells were removed
from the experiment so they won’t cause misrepresentations.
There was a total of 56 unbroken shells in the Virginia Avenue population. The most of the
Virginia Ave population which had zero stripes on them were 39. Twelve had one strip, four of them had
two stripes, and one of them had 3 strips. The number of bands represent the number of lines the shell
had starting from the inner to the outer apex.
The equation used was,

2. Results
Number of Stripes on the Shells of the Groove Snails
60
55
50
Band Number
40
39
29
30
22
18
20
2122
1920
15
14
12
11
8
10
4
8 8
2
1 0 0
4
4
3
1
7 6
1 0
1 0 0
0 0 0
2
0
Virginia Ave
0
39
De Roode
Sample B
14
De Roode
Sample C
19
Ancestor
Virginia Ave. B
Winchester
29
55
0
1
12
22
20
15
7
0
2
4
8
4
8
6
0
3
1
18
11
8
1
21
4
0
2
3
1
0
22
5+
0
4
1
0
0
2
Sample Size
0
1
2
3
4
5+
The results for the previous shows that the majority of the snails had no stripes on them for the
Winchester, Virginia, and Ancestor avenues. Overall, the Virginia Avenue sample B had the most snails
with no stripes. The De Roode Sample B had the most snails to more than five stripes on them.

3. Number of Swirls on the shells of the Groove Snails
60
53
50
45
45
40
34
33
30
30
25
24
Number of Swirls
22
24
17
20
14
8
10
5
3
0000
2
000
3
000
000
2
2
00000
00000
0
Virginia Ave
0
0
De Roode
Sample B
0
De Roode
Sample C
0
Ancestor
Virginia Ave B
Winchester
0
0
0
1
0
0
0
0
0
0
2
0
0
0
0
0
0
3
0
8
5
2
0
0
4
22
34
17
14
0
0
5
53
25
33
30
24
24
6
3
2
3
2
45
45
Population Sample
0
1
2
3
4
5
6
The previous chart shows the number of swirls on the groove snails. The majority had five or more
swirls. Virginia sample B and Winchester had the most number of swirls on them. There were no snails
that had zero, one or two stripes on them. The minority had 3 swirls on them. The rest all had four or
more swirls.

4. To apply them to the Chi-square test, the observed and expected numbers of bands in the
Ancestral population were calculated.
“Number of Stripes on the Shells of the Groove Snails”
0
1
2
3
4
Ancestral
Observed
29
15
8
8
1
Population Frequency
Expected
48%
25%
13%
13%
1.6%
Percentage
Degree of Freedom is 2 for 7.52.
Degree of Freedom is 1 for 4
Degree of Freedom is 1 for 1.92
Degree of Freedom is 1 for 1.92
Degree of Freedom is 0 for 1.92 for 0.225
5
0
0
Total
61

5. The total x2 statistics is 16.
(x2=16, df=1, p<0.05)
Discussion and Conclusion
In conclusion, the population sample of the groove snails according to the variation and traits
was very diverse. Depending on the place they live in Lexington, the snails may have a climate different
in Winchester than in Virginia Ave. For example, they have different colors depending on the place they
live which will help them camouflage. However, the observation was between the number of swirls and
stripes. The swirls will protect them more due to the surface area. My results show that there are more
than four swirls in each of the snails. This proves that it is essential and that the gene isn’t turned off. If
there was a difference between the ancestral or the current population then the ones with the least
amount of swirls won’t survive. For the snails that had swirls, all of them were related. The most
different population was the Virginia avenue sample B which had the most zero stripes. The ancestral
population was different for the reason that it had a variation in the number of stripes. The most
informative trait was the swirls. It told much about the environment that they lived in.