The ancient DNA question for the Texas sites is partly a question about what has been studied and partly a question about what could not be studied because of the conditions of preservation and the decisions about repatriation.

The challenges of ancient DNA preservation in Texas are significant.

DNA degrades over time through hydrolysis and oxidation — the same processes that break down other organic molecules in buried remains.

The rate of degradation is strongly temperature-dependent: warmer conditions accelerate breakdown.

In tropical and warm-temperate environments, ancient DNA survives for much shorter periods than in cold or arctic conditions.

For this reason, the oldest successfully analyzed ancient DNA has consistently come from permafrost sites in Siberia, Alaska, and other cold regions, where temperatures close to freezing slow the degradation process dramatically.

Texas is not cold.