Scott O’Donnell and the biodiversity of wood turtles

Scott O’Donnell is an undergraduate student at ESU. Photo Credit / Chris Powers
Scott O’Donnell is an undergraduate student at ESU. Photo Credit / Chris Powers
Scott O’Donnell is an undergraduate student at ESU.
Photo Credit / Chris Powers


SC Staff Writer

Scott O’Donnell, an undergraduate at East Stroudsburg University majoring with a B.S. in biology and a B.S. in environmental studies, is currently working with Dr. Huffman, professor of biology at ESU, in order to assess the genetic diversity of a recently discovered population of wood turtles, Glyptemys insculpta, in the Delaware Water Gap National Recreation Area.

O’Donnell’s work is a continuation of a study done for a doctoral thesis by Christina Marie Castellano at Fordham University. According to O’Donnell, “She did a genetic study of the populations from 2000-2004, using seven loci to determine the amount of genetic diversity among the populations and between the populations.”

“We are taking a certain population of wood turtles that was going to be affected by construction and updating of power lines…Their habitat range goes through a right-of-way, I believe PPL has, so they wanted to collect and monitor this population of turtles and so they decided to make a genetic analysis on top of it,” O’Donnell said.

O’Donnell worked with others from the university and the New Jersey Fish and Wildlife Service in order to collect nine turtles from this population for genetic analysis.

As he says, “We are going to take those nine turtles and try to develop a multiplex of all the loci of the primers so we don’t have to do as many reactions.”

“We want to basically test to see how many alleles are at each loci for the population and compare that population to the rest of the populations to see how much genetic diversity we have,” O’Donnell said.

Each unique allele within these loci has a different number of base pairs between them, and this can be seen and used to determine allelic diversity between turtles.

Additionally, O’Donnell mentioned, “It would be more to consider if there were a high number of unique alleles in the population to be conserved, because if you lose this population then you would lose more genetic diversity than if you lost a homogenous population.”

In a homogenous population, genetic diversity is more easily conserved in the event of a disruption in the population. However, if a population contains many unique alleles, then a loss of individuals would lead to a much stronger impact on the diversity of the population.

“There is a correlation with high genetic diversity and fitness of the population so the more unique alleles we have, the greater the chance that the population will show high reproduction success,” O’Donnell said.

O’Donnell noted that this species of turtle in particular is important because “the wood turtle is listed as threatened by the IUCN, so it is protected, and habitat destruction really affects this turtle in particular because it has a wide home-range and it is sort-of migratory.”

A part of this project is looking at the impact this power line and construction will have on the diversity of this species of turtle. If the construction could possibly harm the biodiversity of the turtles, then it will also harm the species.

Concerning this situation, O’Donnell said, “It is kind of an awkward situation because the power line company has a right-of-way and a certain number of yards to either side, but at the same time we need to look at the turtle and see if the construction is having too much of an effect on them.”

O’Donnell said, “First we want to determine if there is similar genetic diversity overall, and then we want to determine if there are any unique alleles in the population.”

Once this is accomplished, the wood turtles can be looked at in terms of how they are being impacted by the construction.

O’Donnell summed up his project by saying, “In a broader spectrum that is what this project is, but what we’re narrowly focused on is what this specific population of wood turtles looks like compared to the other populations.”

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