XSIQ
*

Biology - Natural Selection: Introduction

Natural Selection: Introduction

If you look at members of the same species there are slight variations [1]
in structure, body functioning and behaviour. Some of these variations may
give a survival advantage to those who possess them. If these variations
are heritable - able to be passed on to the next generation - then the
frequency of these characteristics will increase in the population [2] over
successive generations. In stable and in changing environments [3] the
characteristics that better suit the individual to its environment will be
selected for and those that suit them less will be selected against. This
is referred to as natural selection. Evolution refers to changes that occur
in species over time. Mutations [4] are sources of new genetic information
and therefore provide the potential for change. Gene flow [5] resulting
from immigration and emigration of individuals (into and out of
populations) and new combinations of alleles [6] in meiosis [7] can
contribute to change in frequency of variations between individuals in a
population over successive generations.

Previous | Next

Links:
------
[1] http://alison.com/#
[2] http://alison.com/#
[3] http://alison.com/#
[4] http://alison.com/#
[5] http://alison.com/#
[6] http://alison.com/#
[7] http://alison.com/#