Basics of
Mutations
Topic 3034
Torey Birchmeier
http://128.113.165.216/ms99/WhitneyW/diseasetest.html
Mutations

A sudden change in the characteristics
of an organism due to a change in the
chemical structure of the DNA.

The change must be capable of being
transmitted fully to future generations
without change.
Mutation

An example of a mutation is the polled
characteristic in beef cattle.
http://128.193.26.240/agcomwebfile/edmat/Vidabs.html
Causes of Mutations
An error in DNA replication
 Exposure to radiation
 Exposure to certain toxic or poisonous
chemicals
 Other genetic abnormalities such as
extra chromosomes or chromosomes
crossing or breaking

Mutations in Evolution

Mutations are recognized as the primary
source of the hereditary variations that
make evolution possible.

Mutations can either be harmful or
useful to species.
Mutations in Evolution

Mutations that help an animal survive
are continued because survivors
reproduce and pass the gene on to their
offspring.

Mutations that are harmful to a species
are less likely to be passed on because
the animals do not survive or
reproduce.
Mutations in Commercial
Agriculture
A Perfect Example……..
 A natural occurring mutation or change
occurred in the horse.


Over many years the horse’s hoof
characteristics changed to suit a
changing environment.
Mutations in Commercial
Agriculture

The one hooved horse today is much
more useful to agriculture than its
smaller four toed counterpart
“eohippus” which lived long ago.
http://205.163.41.21/scripts/agdirect.exe?List_Horse&GLENWOOD&0
Other Mutation Examples
Rust resistant wheat
 Plant breeders have taken advantage of
natural selection for a strain of rust
resistant in wheat.
 Breeders have breed this trait into other
wheat strains to help aid in agriculture
production

Other Mutation Examples
High protein corn
 Geneticists have selected for high
protein varieties and have tried to breed
them exclusively
 This selection is “manmade” rather than
based on “natural selection” such as the
horse

References



Cow Picture: http://128.193.26.240/agwebfile/edmat/Vidabs.html
DNA Picture:
http://128.113.165.216/ms99?WhitneyW/diseasetest.html
Horse Picture:
http://205.163.41.2/scripts/agdirect.exe?List_Horses&GLENWOOD&0