Page 52 - Science Coursebook

3.5 Selective breeding

Water buffalo are kept in many parts of the world. They are

used to pull carts and ploughs, to produce milk and to
produce meat.

Originally, water buffalo were wild animals. People began

to domesticate water buffalo about 5000 years ago.
‘Domesticating’ a type of animal means taming it, so that you
can keep it and use it.

We think that the people who first domesticated water buffalo Wild water buffalo.

took care about which ones they allowed to breed together.
Wild buffalo are very large and can be aggressive. People

probably chose to breed together buffalo that were not too
big, and that were docile (calm) animals. They carried on
doing this, generation after generation.

These features of the water buffalo were affected by the forms

of genes that they had. The chosen parent buffalo passed on
their genes to their offspring.

Of course, the early farmers did not know anything about

genes. They just knew that small, calm water buffalo
tended to have small, calm offspring. Over time, and many

generations, the water buffalo became gradually smaller and A domesticated water buffalo in

more docile. the Philippines.

Breeding sheep

Let’s say that you have a flock of sheep. You
want to improve the length of the wool that We think that the mouflon
your sheep produce. This is what you would do. was the wild sheep from
• Choose the rams (male sheep) and ewes which all today’s breeds of
(female sheep) that have the longest wool. sheep have been produced.
• Breed these rams and ewes together. You
would not let any of the other sheep breed
together. The Merino breed has been
• When the offspring of your chosen rams and produced by selective

ewes have grown up, choose the ones with the breeding for sheep that
longest wool. Allow them to breed together. produce thick, fine wool.

• You would keep doing this for many
generations.
The Assaf breed has been
This process is called selective breeding. produced by selective
Eventually – with much patience, and after breeding for sheep that
many years – you should end up with a flock of produce lots of milk and

sheep with longer wool than the ones you good quality meat.
began with.

50 3 Variation and inheritance

A+E SE