The Tenctonese genetics were based on humans.
Sometime in Earth's history, aliens grabbed a few Humans and used the base DNA to develop the Tenctonese. That's why the two races are so similar. Buck went on to join the police, following in his father's footsteps.
Although Buck was quite rebellious, sticking to the Tenctonese traditions as a way of striking out from his much more integrated parents, he *is* still just a teenager and Tenctonese teenagers apparently experience the same rebellious instincts as Human teenagers. Just a few years later, Buck settles down a lot and realises that he really admires his dad and "Uncle" Matthew. While trying to live up to his hero-worship of his father, the *first* Tenctonese Police Detective, he becomes dedicated to law-enforcement and...- Buck joins the FBI/Interpol/NCIS/SHIELD/SWAT.
- Buck qualifies as a coroner/crime scene investigator/forensic analyst/medical examiner/profiler.
- Buck qualifies as a lawyer and maybe, later, a Judge, or even a Supreme Court Justice. He goes on to become a Senator/Governor/President.
