Population Genetics. Population genetics is a field of biology that studies the genetic composition of biological populations, and the changes in genetic composition that result from the operation of various factors, including natural selection.
Walls, known locally as Waas, (Old Norse: Vagar = Sheltered Bays (voes) - the Ordnance Survey added the ll as they thought it was a corruption of walls. Cf Vagar vÃ¡gar And vagur vÃ¡gur In The), faroe islands is a settlement on the south Side Of, West Mainland shetland Islands. in scotlandne of its old names is  Vagaland , hence the name of the local poet. A pier was built at Walls in the 18th century, and from 1838, it was a center for fish curing. Walls itself is a quieter place than once it was.
There are four islands joined to the Shetland Mainland by bridges, East Burra, West Burra, Trondra, and Muckle Roe. There is also a bridge from Housay to Bruray. Nowhere in Shetland is more than three miles (5 km) from the sea.n addition to the Shetland Mainland the larger islands are Unst, Yell and Fetlar. The definition of an island used in this list is that it is land that is surrounded by seawater on a daily basis, but not necessarily at all stages of the tide, excluding human devices such as bridges and causeways.