Altruism in society: why are people willing to sacrifice themselves?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Biologists call the selfless behavior of animals altruism. Altruism is quite common in nature. As an example, scientists cite meerkats. When a group of meerkats is in search of food, one selfless animal takes an observation position to warn its relatives about the danger in case of approaching predators. At the same time, the meerkat itself remains without food.

But why do animals do this? After all, Charles Darwin's theory of evolution is about natural selection based on "survival of the fittest." So why does self-sacrifice exist in nature?

Gene survival machines

For many years, scientists could not find an explanation for altruism. Charles Darwin made no secret of the fact that he was concerned about the behavior of ants and bees. The fact is that among these insects there are workers who do not reproduce, but instead help to raise the queen's offspring. This problem remained unresolved for many years after Darwin's death. The first explanation for selfless behavior in 1976 was proposed in his book "The Selfish Gene" by biologist and popularizer of science Richard Dawkins.

Pictured is the author of The Selfish Gene, British evolutionary biologist Richard Dawkins

The scientist conducted a thought experiment, suggesting that altruistic behavior can be explained by a special type of gene. More precisely, Dawkins' book is dedicated to a special view of evolution - from the point of view of a biologist, all living things on the planet are "machines" necessary for the survival of genes. In other words, evolution is not only about the survival of the fittest. Dawkins evolution is the survival of the fittest gene through natural selection that favors genes that are best able to copy themselves in the next generation.

Altruistic behavior in ants and bees can develop if the worker's altruism gene helps another copy of that gene in another organism, such as the queen and her offspring. Thus, the gene for altruism ensures its representation in the next generation, even if the organism in which it is located does not produce its own offspring.

Dawkins' selfish gene theory solved the question of ants and bee behavior that Darwin had pondered, but brought up another. How can one gene recognize the presence of the same gene in the body of another individual? The genome of siblings consists of 50% of their own genes and 25% of the genes from the father and 25% from the mother. Therefore, if the gene for altruism “makes” a person help his relative, he “knows” that there is a 50% chance that he is helping to copy himself. This is how altruism has developed in many species. However, there is another way.

The Greenbeard Experiment

To highlight how the gene for altruism can develop in the body without helping relatives, Dawkins proposed a thought experiment called the "green beard." Let's imagine a gene with three important characteristics. First, a certain signal must indicate the presence of this gene in the body. For example, a green beard. Second, the gene must be allowed to recognize a similar signal in others. Finally, the gene must be able to "direct" the altruistic behavior of one individual to one with a green beard.

Pictured is an altruistic worker ant

Most people, including Dawkins, viewed the idea of a green beard as a fantasy, rather than describing any real genes found in nature. The main reasons for this are the low likelihood that one gene can have all three properties.

Despite the seeming fantasticness, in recent years in biology there has been a real breakthrough in the study of the green beard. In mammals like us, behavior is mainly controlled by the brain, so it is difficult to imagine a gene that makes us altruists, which also controls the perceived signal, such as having a green beard. But with microbes and single-celled organisms, things are different.

In particular, in the last decade, the study of social evolution has become under the microscope in order to shed light on the amazing social behavior of bacteria, fungi, algae and other single-celled organisms. One notable example is the amoeba Dictyostelium discoideum, a single-celled organism that reacts to lack of food by forming a group of thousands of other amoebas. At this point, some organisms altruistically sacrifice themselves, forming a sturdy stem that helps other amoebae to disperse and find a new food source.

This is what the amoeba Dictyostelium discoideum looks like.

In such a situation, a single-celled gene can actually behave like a green beard in an experiment. The gene, which is located on the surface of cells, is able to attach to its copies on other cells and exclude cells that do not match the group. This allows the gene to ensure that the amoeba that formed the wall does not die in vain, since all the cells it helps will have copies of the gene for altruism.

How common is the gene for altruism in nature?

The study of genes for altruism or green beard is still in its infancy. Scientists today cannot say for sure how common and important they are in nature. It is obvious that the kinship of organisms occupies a special place in the basis of the evolution of altruism. By helping close relatives reproduce or raise their offspring, you are ensuring the survival of your own genes. This is how the gene can ensure that it helps replicate itself.

The behavior of birds and mammals also suggests that their social life is centered around relatives. However, the situation is slightly different in marine invertebrates and unicellular organisms.