2022-01-24 14:47:32
One of the scientific topics that has excited me the most over the years is the evolution of species. There are several reasons that make evolution an interesting phenomenon. Some of them are not only scientific, but concern, in my opinion, the conflict that certain religions have insisted on maintaining with science. Other reasons are purely scientific, but the most important reason for the interest in evolution is its explanatory power, the power it gives us to explain why living things are like this and not otherwise.
In April 2002, in one of my articles, I dealt with the subject of evolution using the cuckoo as an example, a bird that is not only fascinating for telling the time on the clocks of the same name, but above all for its extraordinary behavior of parasitism. reproductive. Let’s see what he explained then, and what new knowledge has been produced in the last two decades.
Read the article here
So far what I wrote in April 2002 about the behavior of the cuckoo. Obviously, this research topic does not promise million-dollar patents, so it is not investigated intensively. However, some interesting scientific articles have been published in the last twenty years. One of them, published in 2010, addresses in some depth the issue of the evolutionary arms race that takes place between parasitic cuckoo species and their parasitized species. It is necessary to clarify that if the war continues it is because no one has won it yet, but it is possible that one of the species involved will win it in the future, which could lead to the extinction of some of them.
The article indicates that there are two main theories that explain why the arms race between cuckoos and the species they parasitize continues. The first is what we might call the evolutionary lag hypothesis. This hypothesis defends that rejecting suspicious eggs by the parasitized species has a lower cost than accepting them, despite the fact that when rejecting suspicious eggs, mistakes can be made that sometimes lead to the rejection of one’s own eggs. Thus, the idea of evolutionary lag holds that hosts are parasitized by cuckoos only because fully effective defense mechanisms against them have not yet evolved. The hypothesis also argues that parasitic cuckoos fail with certain hosts because the mechanisms to overcome the existing defenses of the species they parasitize have not yet evolved.
Faced with this hypothesis we have the so-called evolutionary equilibrium hypothesis. This hypothesis defends that parasitized species are parasitized because the cost associated with rejecting parasitic eggs is greater than the cost of raising the young of other birds. In other words, rejecting suspect eggs would lead to too many errors in rejecting one’s own eggs, which would have a higher survival cost to the species than rearing all the chicks hatched from the eggs present in the nest, be it whatever its origin. The parasitized species thus reaches a balance between cost and benefit, a balance that benefits the parasitic species.
Both hypotheses are possible explanations for what happens in a situation in which rejecting the eggs by the parasitized species is a complicated task. If the parasitized species identified cuckoo eggs with great ease, without evolutionary delay and without the cost of making mistakes, parasitism would end and or cuckoos would have to raise their own offspring or they would become extinct. However, today both hypotheses are compatible to explain why parasitic behavior can be maintained over generations.
The reason parasitized bird species cannot easily reject foreign eggs is that in the evolutionary arms race parasites successfully employ the weapon of imitation. Cuckoos and other parasitic bird species throughout their evolution have been able to better and better imitate the appearance of the eggs of the species they parasitize. In turn, these have been able to better detect the differences between their eggs and the parasite eggs and have modified their eggs to provide them with their own characteristics, drawings or spots, for example, which can be more easily recognizable by them and at the same time difficult to imitate by parasitic species.
However, the arms race is not limited to imitation and detection of suspicious eggs. since, once hatched, the chicks of the parasitic and parasitized species may also differ to such a degree that the parasitized species can detect and expel the parasitic chick from the nest. For that reason, parasitic species mimic not only the eggs, but also the chicks of the host species, their appearance and behavior, in such a way as to deceive their putative parents.
I’d like to end today with a somewhat philosophical note about what happens to cuckoos and their host species, and the role lying plays in evolution. The environment of the species is not limited to the outside world, but also includes other living species that are not only predators or, on the contrary, symbionts, but use all kinds of tricks and lies to survive in order to take advantage of other beings. alive. Detecting lies is thus revealed as a fundamental tool for survival and, in my opinion, I believe that not only for the survival of species, but probably also of communities, organizations and countries. Here I leave this note for your reflection, dear friends. Take care of yourselves, be happy, and may the antibodies be with you. Oh, and as always, good science!
(Jorge Laborda 01/24/2022)
Links of interest
https://www.cam.ac.uk/research/news/birds-evolve-signature-patterns-to-distinguish-cuckoo-eggs-from-their-own
https://www.nature.com/scitable/knowledge/library/the-ecology-of-avian-brood-parasitism-14724491/
https://www.newscientist.com/article/mg15320732-600-science-transplant-chickens-change-their-tune/
Works by Jorge Laborda.
Your defenses against coronavirus
Your defenses against coronavirus
Deflamed immunology: An introduction to the immune system and its pathologies
Deflamed immunology: An introduction to the immune system and its pathologies
Deflamed immunology: An introduction to the immune system and its pathologies
Kilo of Science Volume XII eBook
Kilo of Science Volume XII Paper
Kilo of Science Volume I. Jorge Laborda
Kilo of Science Volume II. Jorge Laborda
Kilo of Science Volume III. Jorge Laborda
Kilo of Science Volume IV. Jorge Laborda
Kilo of Science Volume V. Jorge Laborda
Kilo of Science Volume VI. Jorge Laborda
Kilo of Science Volume VII. Jorge Laborda
Kilo of Science Volume VIII. Jorge Laborda
Kilo of Science Volume IX. Jorge Laborda
Kilo of Science Volume X. Jorge Laborda
Kilo of Science Volume XI. Jorge Laborda
Matrix of homeopathy
Chained circumstances. Ed.Lulu
Chained circumstances. Amazon
One moon, one civilization. Why the Moon tells us that we are alone in the Universe
One moon, one civilization. Why the Moon tells us that we are alone in the Universe
One Moon one civilization why the Moon tells us we are alone in the universe
The thousand and one bases of ADN and other science stories
Adenius Fidelius
The intelligence funnel and other essays
The gods have been cloned
#Cienciaes.com #studied #Cuckoos #nest