Gene pools and natural selection?

Question

Using the concepts of natural selection and of gene pools, describe how new variations arise in a population and then become frequent within that population?

anybody known the answer to that?

help would be greatly appreciated??

Answer 1

Here is an example you might find useful.

There was a moth in England, (forgot the species, sorry.)

Anyway, this was a light colored moth.  They typically lived near birch trees, which have white bark.  So the moth blended in and birds could not easily see them.

Genetics are cool in that every once in awhile, a mutation happens.  Usually by accident.  So once in a blue moon a dark moth may show up.  Of course this sticks out like a sore thumb and makes an easy target for a bird's lunch.  Hence, the dark moth rarely lives long enough to pass on that trait.

But... with the advent of coal burning machines, industrialization, it didn't take long for every tree in England to be covered in dark soot. So now... when the rare dark moth shows up, IT is the one to be camouflaged and NOT eaten by birds.  

In a very short period of time, the entire species went from light to dark as only the dark ones lived to pass on that trait.

Answer 2

This concept is applied only on sexually reproducing organisms. In this biological concept of species only one feature i.e. potential interbreeding is of primary importance,there is no inclusion of any other feature.

A spicies has following feature;-

1.It is based on the concept of reproductive isolation i.e. spicies is that group of individuals which doesnot reproduce with any other such group.

2. There is common niche(all needs)of species.No two species can have similar niche. There may be overlapping niche.

3.3 A species has the common gene pool (sum total of all genes of all individual).

4. There should be free gene flow(that any female can mate any male of tht species.

5. A species is always in the process of adjustment with the changing environment conditions.Ultimately there is origin of new species.

Ernest mayer give this biological concept in 1942.

Answer 3

This is EVOLUTION, which is the guiding force that changes all living things "for the better".

Your question is very deep and would take an explanation far too involved to get into here.  But, the criteria is that as animals live their lives they discover new things, like a new food source for instance.  Let's say this food is hard to get because it's "inside" something, like the bark of a tree.  It's a wood grub and a bird wants to eat it.  It pecks and pecks at the wood, finally chipping it away enough to get to the larvae.  As the bird continues to do this and others of his species see him and do the same thing, over thousands of years it affects the very "structure" of the birds cells and genetics.  It's beak grows stronger and longer.  His skull gets thicker.  The birds feet grow longer nails and stronger ankles so it can cling to bark better.  The feathers change to help camouflage it from its enemies.  And, low and behold, you have a sparrow that's changed into a woodpecker.  

This all happens on a genetic level and can take thousands or even millions of years.  

This was a VERY generalized and simple explanation of a very complicated process.  I hope it helped.