Question

Humans have taken our knowledge of natural selection and manipulated it artificially to produce a variety of domesticated animals. All breeds of dogs have been produced by this artificial selection. From a wolf ancestor, describe what types of selection patterns have occurred to result in the variety of dogs we see today. difcorent tudes

Answer 1

The deviation of the dogs from wolves has originated as early as 100,000 years ago.Which compared to the geological time scale is very recent as a blink of an eyelid. The dogs have been developed or artificially selected from wolves by humans based on some features. Selection patterns are methodical selection, unconcious slection and natural selection.

Most important of these are --

1. Selection for behaviour-- Those wolves which were less aggressive, and willing to submit to human dominated social structure. So those which are less and less aggressive have been selected by humans and over the years the dogs that have evolved became much less aggressive compared to humans. This is a way of methodical artificial selection.

2. Starch digestion---Wolves have only one gene for starch digestion. They eat meat mostly. But dogs can digest starch present in various cereals as they have many genes for starch digestion. Hu ans cultivate cereals and feed on cereals and starch mroe than other soures of food.So feeding on starch is also important in domestication of the dogs. So those who can feed on starch are selected which is a process of selection which has no concious effort.

So , it is considered environmental selection as humans can't understand which animsl has more genes for starch and which has less. So it is unconcious selection.

3. Morphological features--Many morphological features are preferred by humans for various purposes during the process of domestication. One such example includes Dachshund variety which exhibits Chondrodysplasia. These dogs have short limbs but rest of body size is same. Such a process of selection was important for hunting roles.

This selection process is again a mthodical selection process which involves continuous selection for the trait till required phenotype is attained.

Various other morphological features are also selected by methodical artificial selection.