The
term genetic variation is used to describe the variation in the DNA sequence in
each of our genomes. This is all with these genetic variations that make us all
unique, whether in terms of hair color, skin color or even the shape of our
faces. Genetic variations are the differences in DNA segments or genes between
individuals and each variation of a gene is called an allele. Population with
many different alleles at a single chromosome locus has a high amount of genetic
variation. Genetic variation is essential for natural selection because natural
selection can only increase or decrease frequency of alleles that already exist
in the population. Genetic variation is caused by:
·
Mutation
·
Random Mating
Between Organisms
·
Random
Fertilization
·
Crossing
Over Between Chromatids of Homologous Chromosomes During Meiosis
Geneticvariation among individuals within a population can be identified at a variety
of levels. It is possible to identify genetic variation from observations of
phenotypic variation in either quantitative traits or discrete traits. Genetic
variation can also be identified by examining variation at the level of enzymes
using the process of protein electrophoresis. Polymorphic genes have more than
one allele at each locus. Half of the genes that code for enzymes in insects
and plants may be polymorphic, whereas polymorphisms are less common in
vertebrates.
1.
Analysis
of Genetic Variation in humans
Genetic
variation will result in phenotypic variation if variation in the order of
nucleotides in the DNA sequence results in a difference in the order of amino
acids in proteins coded by that DNA sequence, and if the resultant differences
in amino acid sequence influence the shape, and thus the function of the
enzyme. Almost all human genetic variation is relatively insignificant
biologically; that is, it has no adaptive significance. Some variation alters
the amino acid sequence of the resulting protein but produces no detectable
change in its function.
2.
Analysis
of Genetic Variation in Animals
Genetic
diversity between and within populations displayed by molecular markers receive
extensive interest due to the usefulness of this information in breeding and
conservation programs. The increasing availability of PCR-based molecular
markers allows the detailed analyses and evaluation of genetic diversity in
animals and also, the detection of genes influencing economically important
traits. It can be judged by having knowledge into the dynamic process of
genetic variation in animals by presenting the thoughts of scientists who are
engaged in the generation of new idea and techniques employed for the
assessment of genetic diversity, often from very different perspectives.
Variation is Genetic
Key to Survival
AnilaRani a
renowned name as a professor in biotechnology and conducts various seminars
about various branches and fields concerned with biotechnology. According to
her, you can define genetically healthy population as having a large amount of
genetic variability. The information for each of an organism's characteristics
is carried on a gene, but a gene can have different forms. These are known as
alleles, and a large range of alleles leads to a wide variety of genetic
"options" or genetic "possibilities". She is a professional
trainer that guides various students, teachers, medical students, and many more
in biotechnical topics.
