To reconstruct means "to establish or assemble something again" which inevitably involves an idea of how this something was before it fell apart or was damaged.
Reconstruction of the famous type specimen of the genus Australopithecus, Taung 1. The face and the endocast have been electronically assembled (yellow) and the missing parts reconstructed (blue) with the help of thin plate spline warping using hundreds of landmarks and semilandmarks from a reference specimen (chimpanzee of the same dental age).
Reconstruction of biological objects for various applications, from
forensics to human evolution, refers mostly to the
2. the estimation of missing parts, and
3. the speculations about soft tissue.
As stated above, all these activities are based on very strong assumptions, whether or not explicitly stated. In anthropology, for instance, precious remains of human ancestors are typically reconstructed by a prominent authority and eventually disseminated via images or casts. After that, though, there is often a tendency among researchers to take the reconstruction for granted "as is" without much appreciation of the considerable uncertainties involved and the preconceptions that implicitly shaped it.
Difficulties of reconstruction
A common joke among pollsters says "Prediction is difficult,
especially of the future". For anthropologists, the slogan might be
instead "Reconstruction is difficult, especially of the past".
In both fields, unavailable data has to be estimated, but while opinion
research is mostly based on quantitative data, reconstructions in
paleoanthropology are often a matter of the so-called "morphological
eye". Virtual Anthropology tries to contribute to more objective and
reproducible standards in reconstruction, generally because the
assembly of parts and the estimation of missing parts are according to
definable references. We can distinguish between three approaches to
reconstruct a form: Anatomical reconstruction, geometric reconstruction
(reference based) and statistical reconstruction (reference based). The
physical method can only use the anatomical approach, whereas in
Virtual Anthropology, also reference based reconstruction is
Nevertheless, virtual reconstructions need assumptions as well, most importantly the choice of a reference specimen or population, or else a selection of anatomical constraints. Either way, the reconstruction has still an advantage: it can be repeated without touching the original.
Reference based reconstruction
If a form is distorted, parts have been broken off, or its surface details have been obscured, we have to deal with "missing data" from a statistical point of view.
Essentially, anatomical reconstruction follows the principles of traditional physical reconstruction using anatomical clues to reconstruct a biological form.
Since rich digital data is available in Virtual Anthropology, the process of reconstruction can be enhanced in ways to which physical reconstruction has no access.