Reproduction is “the act or process of reproducing; specifically: the process by which plants and animals give rise to offspring and which fundamentally consists of the segregation of a portion of the parental body by a sexual or asexual process and its subsequent growth and differentiation into a new individual”, as stated by the Merriam- Webster English Dictionary. Sexual reproduction is a process whereby the female gamete fuses with the male gamete to form a zygote, which potentially develops into genetically different offspring. Essentially this means, we combine the genetic information from two individuals of different types or sexes in order to produce a new individual. Asexual reproduction, or agamogenesis, on the other hand is, as stated by Wikipedia, “a mode of reproduction by which offspring arise from a single parent and inherit the genes of that parent only”. Basically, it is reproduction without the fusion of gametes and the offspring produced will be genetic copies of the parent. Asexual reproduction can be advantageous in many ways, for example, due to the fact that the formation of gametes is not necessary, the process of bringing them together is not required, and the involvement of another organism is non-essential, it occurs much faster than sexual reproduction.
Asexual lineages can increase their numbers rapidly because all their members can produce viable offspring. Comparatively, in populations which reproduce sexually, some of the individuals are male, and therefore cannot produce offspring themselves; therefore in an idealistic situation with a sexual population half composed of males, an asexual lineage would have roughly double the rate of population growth. Additionally, asexual reproduction may be advantageous, for example, in cases of low population density, where organisms are able to reproduce without a partner- there does not need to be energy expended finding and courting a partner for reproduction. Change is synonymous to evolution over a period of time, and biological evolution is defined as “any genetic change in a population that is inherited over several generations” by The WorldBook Encyclopedia. For genetic change to occur in a population, genetic recombination must take place, resulting in gradual diversifications of the traits of a species.
In asexual reproduction, because there is no fusion of gametes, the new organism which is produced inherits all of its chromosomes from one parent and thus is a genetically similar or identical copy of the parent. This lack of genetic recombination results in fewer genetic alternatives than with sexual reproduction. This manner of similarity may be beneficial, in cases where the organism’s genotype is well suited to a stable environment, however if the environment is constantly changing, it may be disadvantageous. For example, if an unfamiliar predator or pathogen enters the environment, the entire asexual lineage would likely be wiped out by it. On the other hand, a sexual lineage has a higher likelihood of having more members survive due to the genetic recombination which produces a new genotype in each individual.
From this insight, it becomes clear to us that in terms of biological evolution, or change, asexual reproduction would be a disadvantageous process. According to an article published by ‘Nature’ magazine in 2007, proof of this phenomenon can be seen scientifically today in the arbuscular mycorrhizas fungi, an asexually reproducing organism, is identical to fossil records dating back to 460 million years ago. If, after 460 million years, the organism remained identical, then definitely we can conclude that indeed, asexual reproduction stifles the potential for change.