Therefore, we have to assume that no major changes in the timing and pattern of growth of the mineralized tissues have occurred through time in the target species. The onus is on us to ensure that the genetic difference between the fossil and control sample species is not too great. Luckily, most of the Late Pleistocene and Early Holocene species of interest to us can probably be considered genetically close to their modern counterparts. The possibility of secondary environmental synchrony , requires us to choose sample specimens from environments not too dissimilar from the palaeoenvironments of our target fossil populations. Subarctic be comparable.
More research is needed to determine key environmental features.
If possible, several age groups should be included in the study to establish the existence of any pattern of physiological growth related to ageing. Reliable, year round sources may be difficult to locate depending on the species.