Free Essay On Biological Exemplars Of Natural Selection

Biology

Biological Exemplars of Natural Selection
Ordinary, or gray wolf - Canis lupus - occupies the most extensive natural habitat of all mammals except humans. In the past, wolves inhabited most of North America and Eurasia, but now many of the gray wolf populations remained only small groups, the existence of many of which are not confirmed. The current situation is much more complicated than a thousand years ago, due to the efforts of anthropogenic influences on the distribution of predator and increased possible pressure on its population. Although in perspective wolf areal will be largely determined by human activity, climatic features of the present period should not be completely discounted, and they increase the probability of the next few decades of broad migrations and animal approaches in places where it is still not permanently inhabited (Somervill 2008).
On the exterior, the structure of the skull and ecology wolf has a strong affinity with black (red) wolf, coyote of North America and the jackals of Eurasia and Africa.
Morphological evolution of the wolf during the Pleistocene was negligible. Wide geographical communications of populations caused leveling of appearing deviations obliged by zonal conditions of life. Nevertheless has been observed the trend in the development of progressive predatory type structure of the skull and dental system (Boitani 2000).
Like most wild animals, in wolves well developed cells on the back of the eye. They reflect the light passing through the pupil and give the same wolf shine, which affect animals in the darkness. In the eyes there are two types of receptors: one responsible for the brightness of the image, the other - for the color. In wolves and dogs recognition of colors is not sufficiently developed, but the basic colors they see. Located on top of the muzzle eyes are help them to establish the exact location of the object (Wydeven, van Deelan and Heske 2009).

References

Somervill, Barbara A 2008Gray Wolf. Ann Arbor, MI: Cherry Lake Pub.
Wydeven, Adrian P, Timothy R van Deelan, and Edward Heske 2009Recovery Of Gray Wolves In The Great Lakes Region Of The United States. Dordrecht: Springer.
Boitani, Luigi 2000Action Plan For The Conservation Of Wolves In Europe (Canis Lupus). Strasbourg: Council of Europe Pub.