Selective Breeding | Introduction, Types and Examples

What is Selective Breeding:

Selective breeding is selecting certain individuals with desirable traits to produce offspring with those same traits. It has been used for centuries to improve the quality of plants and animals. In selective breeding of animals, selected males are often used to father many offspring, while females chosen are allowed to have fewer litters. This ensures that more of the desired traits are passed on to the next generation.

In plant breeding, new varieties are created by cross-pollinating two different plants with desired traits. The resulting offspring inherit a mix of both parents’ traits. Through selective breeding, plant breeders can create new varieties that have specific combinations of traits. Selective breeding is not the same as genetic engineering, which involves directly altering an organism’s DNA.

Need for Selective Breeding

• There are several reasons why someone might want to selectively breed an organism. For example, farmers might want to breed plants that are resistant to certain diseases or pests.
• They might also want to produce plants with higher yields or that mature more quickly. Animal breeders might want to create breeds of animals that are better suited for a particular climate or that have certain desired physical characteristics.
• Selective breeding can result in the rapid development of new varieties of plants and animals. However, it can also lead to the emergence of undesirable traits, such as reduced fertility or increased susceptibility to disease.
• To avoid these problems, breeders need to have a good understanding of the genetics of the organisms they are working with.
• They also need to carefully plan each breeding program to ensure that the desired traits are passed on to the next generation.

Selective Breeding procedure

There are two main methods of selective breeding: artificial selection and natural selection.

1. Artificial Selection

Artificial selection is the process of selecting individuals with desired traits to produce offspring with those same traits. This type of selection can be done by humans or by other animals, such as birds that build nests with materials that match the color of their eggs.

2. Natural Selection

Natural selection is the process by which individuals with certain heritable traits are more likely to survive and reproduce than those without those traits. Over time, this can lead to populations of organisms that are better suited to their environment.

One example of natural selection is the evolution of antibiotic resistance in bacteria. Bacteria that are resistant to a particular antibiotic will survive and reproduce, while those that are not resistant will die. As a result, over time the population of bacteria will become more and more resistant to that antibiotic.

Selective Breeding Examples

1. Selective breeding Plants

Farmers have used selective breeding to produce more disease-resistant crops, have higher yields, and mature more quickly. For example, wheat plants that have been breed to be resistant to the fungus that causes wheat rust can produce higher yields than those that are not resistant.

Peas that have been breed to mature more quickly can be harvested earlier in the season, which can be important in areas with short growing seasons.

Cabbage that has been breed to be resistant to caterpillars is less likely to be damaged by these pests.

Broccoli that has been breed to be more tolerant of cold weather can be grown in cooler climates.

     2. Selective breeding Animals:

Animal breeders have used selective breeding to create breeds of animals that are better suited for a particular climate or that have certain desired physical characteristics. For example, some dog breeds were developed for cold climates, while others were breed for their hunting ability.

Dogs

Dogs were one of the first animals to be domesticated by humans, and they have been breed for many purposes. Some dogs, such as retrievers and poodles, were breed for their ability to hunt or retrieve game. Dogs were first-time breed by a common ancestor of the gray wolf (Canis Lupus), which was domesticated to become a hunting companion.

The first dogs were likely breed for their ability to help humans hunt, but over time they have been breed for other purposes as well. For example, some dogs, such as poodles and bichon frises, were breed for their appearance. Other dogs, such as dalmatians and border collies, were breed for their ability to perform certain tasks, such as herding livestock.

Cats :

Cats have first domesticated in Egypt about 3,500 years ago. Since then, they have been breed for many different purposes. Some cats, such as Siamese cats, were breed for their appearance. Other cats, such as Maine coon cats, were breed for their hunting ability. Today, most cats are breed as pets. However, some breeds, such as the Siamese and the Maine coon, are still used for their original purpose of hunting rodents and other small animals.

      3. Selective breeding Livestock:

Livestock animals have been selectively breed for thousands of years to produce offspring with desired traits, such as high milk yield or lean meat. For example, dairy cows have been breed to produce more milk than their wild ancestors. Similarly, pigs have been breed to produce leaner meat than their wild ancestors.

Poultry:

Poultry animals, such as chickens and turkeys, have been breed for many different purposes. Some poultry, such as chicken, were breed for their meat. Other poultry, such as ducks and geese, were breed for their feathers. Today, most poultry is breed as pets or for their eggs. However, some breeds, such as the Rhode Island red chicken, are still used for their meat.

Advantages of Selective Breeding

1. The main advantage of selective breeding is that it can be used to create new varieties of plants and animals with specific desired traits. This process can be done relatively quickly and does not require any special equipment or training.
2. Another advantage of selective breeding is that it allows for the preservation of desirable traits in a population. For example, if a farmer wants to preserve the milk-producing ability of a dairy cow, they can do so by selectively breeding cows that produce large amounts of milk.
3. A third advantage of selective breeding is that it can be used to create plants and animals that are better suited to their environment. For example, farmers might use selective breeding to produce crops that are resistant to drought or pests.

Disadvantages of Selective Breeding

1. There are several disadvantages to selective breeding. One is that it can lead to the emergence of undesirable traits, such as reduced fertility or increased susceptibility to disease.
2. Another disadvantage is that it can result in the loss of desirable traits, such as milk production in dairy cows.
3. Finally, selective breeding can only be used to create new varieties of plants and animals with desired traits if those traits are heritable. This means that not all desired traits can be obtained through selective breeding.