Evolution News - Turns Out Altruism Is For The Fish

Convict chichlid, Amatitlania nigrofasciata

Turns out altruism is for the fish — Osaka City University

Christian fundamentalists will confidently assure you that their religion gives them superior morals to Atheists and members of other religions because they get their morals direct from a perfect god who defines right and wrong. Almost invariably, of course, the same fundamentalists who need to boast about their supposed superior morals are using religion for the excuses it gives them for otherwise unacceptable, antisocial attitudes and behaviour like homophobia, misogyny and/or racism, but that's another issue.

One of the claims they will make against Atheists, for example, is that Atheists see no reason not to be selfish, whereas Christian fundamentalist are altruistic because they know this is the right thing to do, not because it is inherently right but because their god tells them to be and promises them a reward for altruism or punishment for selfishness.

However, evolution by natural selection, operating at the level of genes is fully capable of explaining altruism as an evolved behavioural trait because self-sacrifice can often ensure the survival of those descendants and close kin who are carrying copies of the genes for altruistic behaviour, so ensuring the survival, even at the expense of individual carriers, of those genes through time.

So, this gene-centred evolution should predict altruism in other species; species moreover which don not need to read the Bible to know right from wrong because they have an innate, inherited, set of pro-social behaviours which are also situational - the situation depending on the probability of helping the survival through time of the genes for that behaviour.

This is the finding of a group of researchers from Osaka City University, Japan, whose results were published open access in Nature Communications a few days ago. They have shown that male convict cichlid fish, Amatitlania nigrofasciata can vary their behaviour between pro-social and anti-social depending on the situation.

The Osaka City University new release explains:

Summary

Through a series of prosocial choice tasks, researchers reveal prosocial and antisocial characteristics in male convict cichlid fish. The fish distinguish between female breeding partners, unknown females, and rival males by adjusting their actions to either provide food for both them and the females or avoid providing food for the rival males.

Research Outline

If you were given the option to eat a delicious meal by yourself, or share that meal with your loved ones, you would need as very good excuse ready if you chose the former. Turns out, fish share a similar inclination to look after each other.

For the first time ever, a research group led by researcher Shun Satoh and Masanori Kohda, professor of the Graduate School of Science, Osaka City University, have shown these altruistic tendencies in fish through a series of prosocial choice tasks (PCT) where they gave male convict cichlid fish two choices: the antisocial option of receiving food for themselves alone and the prosocial option of receiving food for themselves and their partner.

“As a result, it can be said that the convict cichlid fish properly distinguish between paired females, unknown females, and rival males, and change their choices according to the situation”, states Dr. Satoh.

However, what exactly happened?

An experimental male fish was placed in a tank, and a fish was presented to the male fish in another tank. When a partner with whom the male fish had experience in raising children was in the presentation tank, the male fish actively made a prosocial choice and both fish received food. On the other hand, when there was no one in the presentation tank, the male fish preferred neither the prosocial nor antisocial option. To understand how the social context affected the fish's prosocial nature, the team changed the partners to rival males or females the experimental male fish had never met before. Results showed the male fish actively choose the antisocial option of not feeding the rival male, while choosing the prosocial option of feeding the unknown female as if it was their own breeding partner. In the latter experiment, the team also presented the original paired female near the experimental tank holding the male fish. In the absence of the paired female, the male fish made the prosocial choice which provided food for the unknown female, but in the presence of the paired female, they made the antisocial choice.

“These PCT results mirror those from similar experiments with primates”, states Dr. Satoh. “However, this is the first time that caring and misbehaving behavior has been observed in fish. No one had ever expected such delicate and exquisite social behavior from such a small fish.” Yet, there is still much work to do. “Through more rigorous behavioral experiments, we hope to clarify whether these fish really have psychosociality and the motivation to produce it and also how the mind of this type of fish evolved to produce it” states Prof. Kohda. There are hypotheses floating around as to the origin of this desire to care. Could it be a link that connects us past our primate ancestors, ultimately back to fish? Let us wait and see what else Prof. Kohda and his team find out.

From the team's paper published in Nature Communications:

Abstract

Human society is cooperative and characterized by spontaneous prosociality. Comparative studies on endotherm vertebrates suggest that social interdependence causes the evolution of proactive prosociality. To test the generality of this hypothesis, we modify a prosocial choice task for application to the convict cichlid, Amatitlania nigrofasciata, a monogamous fish with biparental care and a strong pair bond. We also affirm that male subjects learn to favor prosocial choices when their mates are the recipients in a neighboring tank. When the neighboring tank is empty, males choose randomly. Furthermore, in the absence of their mates, males behave prosocially toward a stranger female. However, if the mate of the subjects is also visible in the third tank, or if a male is a potential recipient, then subjects make antisocial choices. To conclude, fish may show both spontaneous prosocial and antisocial behaviors according to their social relationships with conspecifics and the overall social context.

Satoh, Shun; Bshary, Redouan; Shibasaki, Momoko; Inaba, Seishiro; Sogawa, Shumpei; Hotta, Takashi; Awata, Satoshi; Kohda, Masanori
Prosocial and antisocial choices in a monogamous cichlid with biparental care
Nature Communications 12, 1775 (2021). doi: 10.1038/s41467-021-22075-6

Copyright: © 2021 The authors. Published by Springer Nature Ltd.
Open access.
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)

Altruism in fish, which no theist would claim is motivated by religious considerations or comes from reading the Christian handbook of morals, aka the Holy Bible, clearly indicates that it evolved because there was some benefit to the male chichlid in alrruistic behaviour. This illustrates how this apparently selfless behaviour is an evolved trait. Paradoxically, 'selfish' genes are perfectly capable of producing superficially selfless behaviour, if that behaviour is in their long-term benefit and result in more copies of themselves in descendant generations.

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