He parasitism is the type of association and lifestyle of parasites . These organisms live at the expense of other species, which they feed on without killing them.
With parasitism, one of the species (which acts as host or Guest) undergoes a weakening of their reproductive capacity before the action of the other species (the parasite ), which benefits by improving its own reproductive aptitude.
The parasites they can live inside the host and receive the name of endoparasites , or reside abroad and be known as ectoparasites . The parasites that ultimately kill the host are called parasitoids .
Parasitism can be defined as a process that allows a species to improve its ability to survive at the expense of another, whom it uses to meet its basic needs. It is important to note that the species that acts as a host is harmed by this interaction .
Throughout the different generations, the parasitic species ends up producing morphological and physiological transformations since the interaction is established from natural selection.
The parasites themselves can become, in turn, a host of a third species, which is called hyperparasite . There is, in these cases, a kind of chain, where the hyperparasite exploits the parasite, and the parasite does the same with the host.
Host organisms usually develop defense mechanisms to prevent the parasites from working. That is the case of plants that produce toxins to deter parasitic fungi.
Beyond the biology , it is known as parasitism at habit of one who lives at the expense of another person . For example: "I'm sick of Hugo's parasitism: if he doesn't look for work, I'll throw him out of the house".
Parasites and evolution
When talking about parasites, the focus is usually on the hurt that they cause in their hosts and in their inevitable adaptation to the immune response. However, the hosts must also learn to live with their small invaders, since they collaborate with natural selection; In other words, the parasitic population and the organisms in which they reside evolve in parallel.
East phenomenon So remarkable parasitism gives us the tools to understand, for example, the higher frequency of occurrence of the sickle cell anemia gene in endemic regions of malaria. Usually, parasites choose their hosts very carefully and in most cases they only relate to a particular species. In addition, virtually all living things, regardless of size (even microscopic), have a parasite that they do not share with the rest.
If we add to this the fact that some parasites are hosts of others, as in the case of hyperparasitism, it is correct to say that the proportion of parasites in the flora and fauna worldwide is really very high.
It is worth mentioning that there is a very concrete reason why parasites do not kill their guests, and that they depend on them to continue existing and evolving. Through bliss evolution, for example, most biological pathogens (those capable of causing damage or disease in the organisms in which they are housed, whether they are animals or plants) end up becoming parasites.
When the bond between both parties is very narrow, it can happen that both experience a phenomenon called co-specialization, whereby the parasite can search for a partner to procreate in the body of the individual with whom its host mates. Cases have been studied, such as that of the foamy virus of the apes, in which this relationship has lasted millions of years, and that is why its observation is essential for biology.