Whether this analysis has been applied to the Texas cave and sinkhole populations in ways that have entered the published record is uncertain, but the technique represents one of the scientific tools that might illuminate questions about where these individuals came from and how far they traveled.

Physical anthropological measurements and comparisons of skeletal morphology — the shape of skulls and other bones — have been used to assess the biological relationships between ancient Texas populations and other ancient American populations.

These analyses are more limited than genetic comparisons, because skeletal morphology reflects the combined influence of genetics, development, and environment, and because the range of variation within populations often overlaps substantially between populations.

But in the absence of genetic data, morphological comparisons have provided at least partial information about biological affinities.