Question

Useful Formulas

H = 1 – 1/ [2Ne]             (Ne)= 4(N_m x N_f) / (N_m + N_f)                      H_t = H^t              (Ne) = t / (1/N₁ + 1/N₂...1/N_t)

3. A population of timber rattlesnakes in eastern Kentucky is surveyed to estimate genetic diversity and structuring of the species across the landscape. Six populations are tissue sampled and are genetically analyzed; these appear to be metapopulations that are fragmented and separated by surface mining. The following data describe the distribution of genetic diversity within this population. H^P = 9% D^PT = 91%. Explain these findings and why they may or may not be important knowing that 3 of these 6 populations are at risk due to surface mining permits being issued for land they occupy.

Answer 1

H_p indicates mean within population variation ( indicating population level heterozygosity )

D_pt indicates mean among population variation ( indicates mean divergence among the population )

H_t indicates total genetic variation ( H_p + D_pt )

1. H_p is given as 9% and D_pt is given as 91%. Population size is not given.

Points to be considered:-

• Changes in natural distribution of genetic diversity would result in loss of genetic diversity. It may occur due to artificial isolation of population or my mixing populations isolated naturally.
• Total genetic diversity depends upon the heterozygosity within population and genetic differences between different populations.
• 91% indicates mean divergence among the population . Partitioning analysis helps to identify these genetic changes or similarities.
• For conservation of genetic diversity, both within-population and among-population genetic variation should be considered. This can maintain a natural variation structure.
• If the value of D_pt is more, then it would be difficult to maintain the isolation as much divergence can be seen. If opposite is the case, then conditions would be presence of more similar population with less divergence.
• Strong genetic divergence indicates much better adaptations and hence these findings may prove useful in terms of construction approval as genetic diversity may not be lost in terms isolation cannot be maintained.