Advantages and disadvantages of asexual reproduction

Asexual reproduction is one that is carried out with a single parent and without the intervention of the nuclei of the sex cells or gametes . It can occur in both cellular and multicellular organisms, having advantages and disadvantages that we will tell you below.

What is asexual reproduction and types

Asexual reproduction is one that requires only one organism, which does not need to mate to form new beings . Since there is no intervention of sex cells in an act that would involve two organisms, there is no genetic exchange or combination: the offspring, in that sense, is identical to the parent.

This type of reproduction, so important for the life cycle of a species, is typical of unicellular organisms such as prokaryotes and protists; but it is also common in fungi, invertebrates, and plants. Possibly in most cases, in the most complex forms of life, reproduction is sexual, although animals with asexuality also occur.

There are different types of mechanisms to carry out the same asexual reproduction.

• Budding:  protrusions or buds are produced in the same body of the parent from which an independent organism later emerges. This detaches and lives autonomously or remains on and develops a colony. In cnidarians and porifers it is very normal. Single-celled organisms such as yeast or bacteria also use this method of reproduction.
• Fragmentation:  In this case, new individuals are produced from fragments of the parent’s body, building a new one from one part of the other. It is very normal in invertebrates such as starfish and also in some plants.
• Binary fission:  It is possibly the simplest method of asexual reproduction, since it consists of the duplication of the genetic material (DNA molecules) of the parent. It is followed by the division of the organelles and finally the caesura of the cytoplasm, thus obtaining two identical cells where there was only one before. It is typical of prokaryotes, but also of some eukaryotic single-celled organisms.
• Sporulation:  It is a reproduction through resistant structures called spores, unicellular in nature. It can be both part of the organism’s life cycle and susceptible to hatching due to certain environmental conditions.
• Apomixis: This mechanism  is typical of plants and involves a form of asexual reproduction through seeds, which does not imply fertilization or meiosis. Here the organism produces genetically identical seeds, which allow the species to be prolonged, but without so much adaptability to the environment.
• Parthenogenesis:  This method of sexual reproduction involves the development of unfertilized female sex cells, that is, possessing the same material as the parent, through a segmentation of an unfertilized ovum. It is typical of invertebrates, but also vertebrates.

Advantages of asexual reproduction

There are certain advantages when it comes to talking about asexual reproduction. The most obvious is that it is both fast and simple , since it does not require the production of specialized cells as in the case of gametes (let’s think about the ovum and the sperm), nor to spend energy for any type of fertilization.

On the other hand, as far as reproduction is concerned, a single isolated individual can give rise to a multiplicity of others, descendants, all genetically identical with the parent and with each other.

Finally, it can be added that simplicity and speed is useful in situations of biological irrigation or rapid expansion. If there is a colonization of a territory or in the face of danger, a massification is essential, the asexual method of reproduction is ideal.

Disadvantages of asexual reproduction

Possibly the great disadvantage of asexual reproduction is its nullity in terms of genetic variability , because, except for unforeseeable mutations, the descendants will be the same as the parent in this aspect. What does that imply? That the species evolve at a slower and less effective rate. Here, then, there is no natural selection that favors the fittest to survive.

The situation of absence of genetic variability can cause a colony or a species to end quickly, since it can prevent it from adapting quickly to changes in the environment.