In the Dragon Ball universe, it's not only Son Goku and Vegeta who have merged; numerous other characters have undergone this transformative experience.

Professor Naoki Wada, an expert in cellular technology, shared his research on fusion in Dragon Ball Z and its potential to lead humans into becoming Namekians in the future.
During an interview on November 23, 2023, Wada disclosed being a member of the world's first team to achieve cellular fusion between human and plant cells. His theory, known as the Unified Gamete Theory, revolves around both individuals transitioning into a gamete phase.
These gametes would unite and rapidly evolve into a singular organism. Although the synthesis of gametes in real life is extremely rare, it can occur, resulting in what is termed as 'natural unity.'
The professor explained that human cells carry two sets of genetic information, one from the mother and one from the father. Typically, new cells are created by duplicating existing cells, resulting in cells with two sets of genetic information (somatic cell division).

Nevertheless, during the formation of sperm and egg, each cell possesses only one set of genetic information, containing half of the original set, in a process known as reduction division. Gotenks, a fusion character in Dragon Ball, carries four sets of genetic information. According to Professor Wada, if cell division occurs, the resulting cells will again have two sets of genetic information, enabling Gotenks to rapidly split into Goten and Trunks.

However, this theory still encounters several challenges. For instance, how do you develop cells quickly enough for useful synthesis reactions in battle, given that the human fusion process typically takes nine months? Moreover, it is essential to ensure that Gotenks retains his memories during and after fusion.
Professor Wada's current research delves into the potential use of chloroplasts, which plants utilize for photosynthesis, inside animal cells. This could lead to the creation of photosynthetic animal cells, a development that might generate life forms resembling the Namekians in the distant future.
If this technology becomes feasible, there will undoubtedly be significant interest in it. People are ready to explore changes in biology and humanity to seek unique and fascinating experiences.