Evolutionary convergence: what it is and examples

The animal kingdom is very diverse, with all kinds of species with very different abilities. However, on more than one occasion we may see two animals having limbs or organs that share the same function, even though they do not appear to be related.

Evolution, while diverse in each animal species, can lead to the same result, causing two or more species to develop parts with similar functions. This is called evolutionary convergence, Process which we will see in more detail below.

  • Related article: “The Theory of Biological Evolution”

What is evolutionary convergence and when does it happen?

Evolutionary convergence is the evolutionary process from which two or more organisms that are phylogenetically separated give rise to similar structures, With a similar morphology. In other words, they are two species having an organ or a member that serves them for the same function, even though the two species do not appear to be closely related in the evolutionary tree.

To give a few examples, we have the case of extinct bats and pterosaurs, both of which have wings, although one does not descend from the other and their common ancestor does not have these limbs. The ancestor of bats and birds did not even have wings, so at one point these animals had to develop wings, but separately.

Another example is that of sharks, dolphins and ichthyosaurs, animals that share very similar morphology, but which turn out to be very different and phylogenetically distant. These marine animals are shaped like a spindle or torpedo, which makes them more hydrodynamic, making their movement in the water much faster and more efficient. Despite their morphological similarity, they have no common ancestor with this form.

Why is this happening?

Evolutionary convergence is a phenomenon that occurs because two or more species need to solve the same problem, albeit alone. These species must adapt to their ecological niches to survive and, therefore, they must develop the appropriate skills to be able to ensure their survival.

Nature endows convergent species with the same solution to the same problem, but in each of the evolutionary branches. So, if two species need to fly, they will need to develop limbs that allow them to do so, or if they need to swim, their bodies will need to acquire a more hydrodynamic shape and develop fins.

Example: the case of sar chopa and humans

The sarg chopa fish (archosargus probatocephalus) and humans are an example of how convergent evolution occurs.

Fish have teeth that can look as funny as they are disturbing, as their teeth are very similar to those of humans. It is clear that fish are not descended from monkeys, so What is the evolutionary explanation for such a striking trait?

One thing we share with Sarg Chopa is that we are omnivorous as well, and our prosthetics prove it. We have teeth for tearing flesh, like canines, and teeth for crushing nuts and gnawing at roots, like molars.

The sarg chopa also has a diet that basically resembles human and for this reason its teeth have evolved in a way so similar to ours.

The reverse situation: evolutionary divergence

As we have mentioned, there are species which, although not related, quickly develop limbs and organs with similar functions. But, in addition, in nature the opposite situation can occur, that is to say that two or more organisms with a common ancestor modify some of their common traits, Adapt to environmental requirements. This phenomenon, called evolutionary divergence, is one of the most studied cases in the limbs of mammals.

For example, if we compare the arm of humans, the wings of bats, the hooves of horses and the claws of tigers, we will see that they are very different. Our hands are used to grabbing things, the wings of bats to fly, the hooves of horses to walk, and the claws of tigers to attack and tear flesh.

These species have one ancestor in common, from which we have inherited the same bones in the limbs, but with some differences in their shape. Evolutionary divergence has been the phenomenon that has given each species a different function.

    Evolutionary convergence and animal intelligence

    There are many species in the animal world. The funny thing is that, and thanks to studies in primatology and anthropology, we have seen that humans, although we can say that we are the most intelligent species to date, we are not the only ones with striking intellectual aptitudes. Primatology has been shown to show that other primates, with whom we are related, exhibit sufficiently sophisticated intelligence. This makes sense, because these are species that are close to us in the evolutionary tree.

    However, it is also surprising that species far removed from our own, such as octopuses, parrots, and crows, have a very prominent intelligence in the animal world. We are not descended from, for example, crows, and octopuses are not descended from us, and therefore our intelligence and theirs are not directly related. Their intellectual capacities are due to processes of evolutionary convergence, to be able to effectively solve different environmental demands.

    The study of animal intelligence is quite old, dating back to Charles Darwin and the time when he published his most famous work, The Origin of Species (1859). Since, scientists have tried to understand how animal thought works and its similarities or differences with the intellectual capacity of human beings.

    We understand animal intelligence as the set of skills and abilities that allow animals to survive environmental demands, adapting to their ecological niches.

    Among the most intelligent animals, apart from the human species, we have the following.

    1. Octopuses

    Octopuses are cephalopod molluscs, invertebrate animals that display a very striking intelligence. We have experimented with them a lot and we have seen that they can perform complex tasks such as opening a jar to get what’s inside. They have excellent short and long term memory and a great ability to learn.

    One of the most important octopuses is the mim (octopus) which has the ability to imitate other species of animals, camouflage themselves or impersonate a more dangerous animal and thus protect themselves from predators.

      2. The dolphins

      It is known in popular culture that dolphins are very intelligent and sociable cetacean mammals. They have developed an amazing adaptability, And they are able to pass information to each other, help each other if they are injured or sick, and can even make their own sounds for each individual, as if they were names.

      Although they were not able to fully teach the language, they did learn some concepts, most notably Louis Herman’s experiences in the 80s with the Akeamakai and Phoenix dolphins.

      Akeamakai was trained in sign language with the arms and legs of her caregiver. Phoenix was trained in artificial click-like language that could be heard by underwater speakers. Each language contained between 35 and 40 words, which referred to pool objects, actions, location, and address.

      Although 40 words are very few, knowing what they mean and making syntactic structures with them is a truly amazing thing to make dolphins the most intelligent group of animals in the sea, along with octopuses.

      3. Chimpanzees

      As we have seen, it is not surprising that chimpanzees and apes in general exhibit advanced intellectual abilities, given their proximity to we.

      Their social skills, as well as their ability to use toolsLike the paddles for extracting termites from logs or stones for opening fruits and their great memory, make them the most intelligent non-human animal species to date.

      4. Pigs

      To unbelievable it may seem that pigs are very intelligent animals. In fact, research suggests that an adult pig has more or less the intelligence of a three-year-old, Far above the intelligence of other pets.

      5. Parrots

      Parrots are intelligent birds, not because they can repeat words of human language. These animals have the ability to differentiate and recognize different human faces, and although their ability to “speak” is rather by imitation, they have a great memory that allows them to remember how to make such sounds.

      However, and since they are able to repeat human sounds, science has not missed the opportunity to try to teach them to speak, being very famous the case of Irene Pepperberg and her gray parrot Alex (Psittacus erithacus ).

      After 13 years of experimenting with Alex, Pepperberg managed to teach him 80 words and to understand its meaning, which included object names, shapes, numbers and certain verbal sentences, in addition to the functional use of “yes” and “no”.

      6. Elephants

      Elephants are widely known as very intelligent animals, and their brains are, in fact, the largest in the world. While in the animal world, larger size does not necessarily mean greater intelligence, it should be noted that in the case of elephants there appears to be a certain relationship.

      They have an incredible capacity for socialization, In addition to feeling empathy and feelings that until recently were considered purely human, such as compassion, grief or selflessness.

      They can, when they see the bones of an elephant, stop and pay homage to it, recognize that these bones had life and were one of its congeners. In addition, they are aware of themselves.

      7. Crows

      These birds are known in general culture to be intelligent, intelligent Machiavellian. They are able to build tools, use them and keep them for other occasions.

      Additionally, they can troubleshoot issues and the reason, which makes them especially smart when trying to steal things. They are aware of themselves and others and can remember other individuals of their species. They are also able to remember a particular human being if they find it dangerous.

      8. Rats

      Finally, we have the animal most used in experimentation: the rat. These rodents have quite developed intellectual abilities, which is why they are so used in psychology laboratories. They have quite remarkable empathic abilitiesUsing with their fellows, they are even able to sacrifice themselves for the common good.

      We have seen that they dream in a very similar way to people, in addition to being able to get out of the most complicated mazes thanks to their ability to analyze situations with the different sensory stimuli they receive.

      conclusions

      From evolutionary convergence and divergence, we can analyze that the characteristics of organisms do not always allow us to easily know what their common ancestor was. It may be that two species are very distant phylogenetically, but use the same member for the sameIn other words, they have undergone a process of evolutionary convergence.

      On the other hand, it may be that two species will soon be related in the evolutionary tree and, however, due to environmental demands, some have chosen to use an organ or a limb for a function while others have chose to do so. for something else.

      Finally, we need intelligence in the animal world, especially that of species like rats, crows, dolphins, parrots, pigs, and octopuses that can be related to humans.

      This is not because we are phylogenetically close to each other, which is not the case, but because these species, in the face of a certain environmental demand, have been forced to show advanced intellectual capacities. in order to be able to survive.

      Bibliographical references:

      • Cortès-Colomé, M. (2016). Psychology of linguistic communication. Madrid: Synthesis.
      • Fontdevila, Antonio and Andrés Moya. (2003). Evolution: Origin, adaptation and divergence of species. 591 pages. Editorial summary. ISBN 849756121X
      • Arendt, Jeff and David Reznick. (2008). Convergence and parallelism have been redesigned: what have we learned about the genetics of adaptation ?. Trends in Ecology and Evolution 23: 26-32. ISSN 0169-5347

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