Problem 1 A small (avg 2’ tall) shy mammal was found on three islands. On island

Question

Problem 1
A small (avg 2’ tall) shy mammal was found on three islands. On island A (a small island) the population is estimated at being approximately 175 individuals. This island is close to other similar size island (Island B), and a third, much larger island (Island C). This mammal is indigenous to all of the islands. Recent surveys place the total number of animals at ~700 for the entire species. The last genetic analysis of the populations was conducted many years ago. The survey was conducted utilizing 10 allozymes loci on island A, B and a sub-population on island C. Below are the results:

6 alleles in total were identified with the 10 loci. The F coefficients were examined; island A’s F=0.91, island B’s F=0.39. The animal was seen to live in groups of 10 to 100 individuals. Individuals typically reach sexual maturity at one to two years of age, after which time breeding can be continuous. The mammal rears only one young at a time and can only rear 1 offspring approximately every two years. Breeding can be affected by the rainfall. Predation is believed to come from small carnivores and feral cats. At the time of this study 52% of the females on island A were lactating, but 92% were lactating on island C.

1. Briefly summarize the information you were given in your own words and your initial concerns (if any):

2. Briefly explain the significance of the data provided with regards to island A and then as a total species (Hint* IUCN status/criteria, ecology of the species, Ne, diversity, etc…)

3. As the new researcher on the team what would you do differently or add to research?

4. How would you increase the genetic diversity of the island populations with a low F coefficient?

5a. If you are able to increase the genetic diversity on island A what would you think would happen with the F value and would this change be fast or slow, and why?

5b. Can you use Island A as an ideal source of restocking any other population?

Island Proportion of Loci Polymorphic Number of alleles Avg Heterozygosity A 0.1 1.2 0.05 B 1.0 3.4 0.62 C 1.0 4.4 0.56

Explanation / Answer

Answer 1)

The information is about an indigenous mammal present on three islands A, B and C. The third island is a bit bigger than the first two islands. The total number of mammal species counted on the three islands is 700. Out of these 700, 175 individuals are present on Island 1.

This means that (700-175=) 525 individuals are present on island 2 and 3.

10 loci were studied in this mammal and it was found that there were 6 alleles in total. The F coefficient of Island ‘A’ was quite higher (three times) than that of Island ‘B’. This shows that inbreeding of Island ‘A’ is quite high. Therefore, average heterozygosity (=0.05) is very low. So, the offsprings produced on Island ‘A’ may not be so strong and viable in comparison to those of Island ‘B’. Average heterozygosity on Island ‘B’ (=0.62) is high; which further leads to low F coefficient.

At the present time, 52% females of Island ‘A’ are lactating. This means that only 48% can give offsprings. These 48% will inbreed among themselves to give offsprings. So, the offsprings will not be much good.

On the other hand, 92% are lactating on Island ‘C’. So, only 8% can give offsprings over here in the next two years.

So, there is only Island ‘B’ left where viable offsprings will be produced. This also depends on the number of lactating mammals on Island ‘B’; which has not been given.

The main point of concern is that there will be overall loss of heterozygosity in the near future. This mammal’s population will also reduce in the near future. This is because Island ‘C’ will produce hardly any offsprings in the next two years. And Island ‘A’ will produce offsprings of less vigor.

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