Hybrid children are not something you would expect from some very different alien species, because there are many barriers for different sapient species to want to have offspring together.
For instance, many alien species are so different that they would not generally be attracted to each other. For example, beamen are attracted to things like the summer coat, which are display structures that only other beamen have. Plus, sapient species have very different love lifestyles and rituals. Humans kiss to show affection, while beamen stroke each other instead. Humans generally only have children with lifelong partners, while beamen are not at all monogamous.
But despite all this, members of different alien species do sometimes want children together. This is common in multicultural cities, especially those with many sapient species freely mingling. For some time, it was thought ridiculous that two far-flung sapient species with vastly different physical characteristics could create a child together. But now there is a solution- GECCAI.
(pictured: a human/Azi lana hybrid created using GECCAI technology)
GECCAI, or Gene Editing/Child Creating Artificial Intelligence, is a gene-editing machine that uses AI technology to create a functional child using the DNA of two seperate sapient species. It uses a database of information about the function of genes from thousands of different sapient species to create individuals with characteristics of both of the parent species.
All that is needed to create one of these children is a genetic sample from both parents. These hybrids are often exotic combinations of traits from both the parents, and sometimes don’t really resemble either one.
Hybrid people are naturally infertile due to their mosaic genome; they require GECCAI to have children of their own, which has had social implications for hybrid people.
If hybrid people have children with people from species who aren’t those of either of their parents, the children can become progressively more unusual, and there are rare cases of several generations of this resulting in people who are physically or mentally disabled, or unable to have offspring, even with GECCAI.
On the other hand, if a hybrid person has children with a person who is of the same species as one of their parents, the hybrid person’s other parent’s genes can effectively be watered down.
After several generations of these genes being watered down, the resulting person is fertile and, under most societies, no longer considered a hybrid- despite some odd characteristics they may still retain.
GECCAI, despite its popular use by alien species to create hybrid offspring, was not originally invented for that purpose. It was originally invented on Earth, in the 22nd century, by human scientists Merinda et al, as a way for gay couples to have children that were related to both parents. It was not until the mid-23rd century that the superintelligence Anwarth appropriated the technology to provide services to wanting human/Azi lana couples.