Reference no: EM133368806

Assignment:

Effects of Selective Hunting on Bighorn Sheep

Many species of large mammals are hunted around the world, and management efforts have traditionally focused on sustaining populations so that the animals harvested by hunters is offset by animal reproduction. A key part of this effort is setting minimum size for harvesting, such as a minimum antler size in deer or a minimum horn size in wild sheep. For example, bighorn sheep (Ovis canadensis) is a species of wild sheep living in western North America. To ensure long-term sustainability of sheep populations, there is a limited number of hunting permits given to harvest them, with some permits being auctioned for more than $100,000. As a result, the hunters receiving these rare permits typically want to harvest trophy males, which are those that have the most massive bodies and the longest horns.

1. Given the strong preference of hunters to harvest male bighorn sheep with the most massive bodies and longest horns, what do you predict will happen to the average body mass and horn length over several decades of hunting?
2. Using the data provided on the mean body mass and horn size of 4-year-old male sheep, draw a scatter plot graph to examine how body mass and horn size changed over time.
3. Based on these graphs, how has hunting caused evolution of sheep traits over time?
4. How would the magnitude of heritability for each trait affect these evolutionary outcomes?

Year	Mean body mass (kg)	Mean horn length (cm)
1972	83	63
1974	76	No data
1976	75	No data
1978	72	66
1980	80	65
1982	77	67
1984	80	62
1986	73	58
1988	73	62
1990	80	54
1992	63	60
1994	73	47
1996	65	46
1998	65	52
2000	65	38
2002	56	55