We talk about the unconscious selection during social interactions and the correlation with Oxytocin. Now it gives examples of doing research with cats, domestic horses, etc.. because they also have the hormone Oxytocin, nicknames the love hormone, however fish has a love hormone called Isotocin.

My question is can we have a dog/human bond like we have but a fish/human bond. Why is it that Oxytocin in different species seem to react with other species that have Oxytocin but why it doesn't react or does it react to a different species with Isotocin even though both of these hormones have very similar reaction (example: love hormone)?

"Reddon and his research team studied the cichlid fish Neolamprologus pulcher, an unusual species that forms permanent hierarchical social groups. Each group has a dominant breeding pair with many helpers to look after young and defend territory." -Marinesciencetoday.com

Read more: http://marinesciencetoday.com/2012/10/11/fish-also-react-to-the-love-drug/#ixzz5yVbxqrx7

When a neutral allele is linked to beneficial allele, consequently meaning that it has a selective advantage, the allele frequency can increase in the population through genetic hitchhiking (also called genetic draft).

Reference: https://courses.lumenlearning.com/boundless-biology/chapter/adaptive-evolution/

The evolutionary process in which larval or juvenile features of an ancestral organism are displaced to the adult forms of its descendants. It can arise by neoteny or progenesis.

So from my understanding, this is showing comparable traits to other species that have been related at some point in the taxonomy but only in larval or juvenile stages of life. After this stage in life, the traits will fade.

Reference: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0164562