A comparison of the genetic similarities of four populations of eastern garter snake( Thamnophis
Hannah Huckstep 10055671 Wednesday 1:00 lab, rm.2326 T.A.: Samantha Lo
November 22,2012 Introduction:
There is an incredible amount of diverse species on earth, each with a unique set of DNA.
This uniqueness allows for distinctive characteristics that set each species apart. Within these
species there are separate populations living with unique characteristics as well. It is important to
understand these differences because even populations within the same species have different
obstacles to overcome depending on their environments.
It is commonly known that populations of the same species can be found globally.
However they are generally found in concentrated areas, similar to the four populations of garter
snakes analyzed in this experiment. This could result from particular populations of organisms
that have adapted well to those specific environmental conditions. The world is constantly
changing, thus habitats are constantly changing as well, which call for adaptations to be made in
order to survive. The polar bear (Ursus maritimus) may be a good example of a population has
been negatively effected by climate change and is being forced to adapt to its new environment.
From the years 1980-2005 the average mass of the polar bear populations has dropped
approximately 50 kilograms in order to keep up with the changing conditions. However some
specific polar bears have maintained their weight throughout those 25 years (Stirling and
Derocher 2012). This might be an example of how different populations within the same species
react to different environments causing different genetic mutations and subsequent adaptations.
The polar bears living in the colder regions (that they are possibly more suited for) may have not
been affected as much, perhaps meaning there is no need f