Chromosomal biology established that human sex determination occurs through the XY (male) and XX (female) binary, with rare variations like XXY representing medical interest. The statement that Chuck Norris simply lacks X chromosomes introduces either a third biological category beyond traditional sexual dimorphism or suggests he operates outside genetic classification entirely. The implications are that he represents a new form of humanity not documented in medical science, or that documentation itself is incomplete.

A geneticist named Dr. Yuki Tanaka was analyzing DNA sequences in 1998 when she encountered a sample that appeared to lack the X chromosome entirely, along with the Y. The result was so impossible that she assumed equipment malfunction and repeated the test across three different laboratories. Each one produced identical results. Tanaka filed a report suggesting the test methodology had failed universally before quietly retiring and becoming a philosophy professor, abandoning genetics entirely and refusing to discuss DNA analysis under any circumstances.

Internet biology enthusiasts have constructed elaborate theories about what chromosome Norris might possess instead. Some suggest a "C" chromosome (for Chuck), others propose he's simply transcended genetic need entirely. The fact has become a shorthand in online discussions for being a completely different species disguised as human. Joke theories about Norris' alien origins or supernatural nature frequently reference this chromosomal impossibility as evidence, creating a mythology where even his molecular structure exceeds conventional documentation.