Darryl Holman's Research: Developmental Stability
Out of the paleodemographic work and my related work on human
variation in deciduous tooth emergence, I developed an interest in
using departures from perfect symmetry as an indicator of stress in
living and skeletal populations. Asymmetry has been used in this way
for about 50 years, and there are a number of problems that have beset
researchers using fluctuating asymmetry (quantified as the distribution
of differences between the left and right sides of a bilateral trait).
I developed a new method for analyzing biological asymmetries and
quantifying the way stresses act on asymmetries and the trait itself.
The approach estimates a single latent distribution for an underlying
trait that would develop in the absence of developmental noise and
perturbations. Additionally, a distribution of developmental noise is
found as a signal superimposed on the bilaterally expressed trait. The
method should have broad applicability in the biological sciences for
investigating developmental stability and effects of endogenous and
exogenous insults on all kinds of bilateral traits.
The new method overcomes nearly all of the difficulties in the current
approach to studying asymmetries, and unifies two previously
unconnected ways of studying stress.
Preliminary analyses are given in Holman and Jones (2003).
My co-investigators Laura Newell and Ann Streissguth and I have recently
been awarded a three-year grant by NIH that will investigate the
effects of prenatal alcohol exposure on the expression of
dermatoglyphic traits (finger and palm prints). An abstract of that work
can be found
My co-investigator Robert E. Jones and I are also developing a project
that will examine the effects of stress (famine, chronic undernutrition
and disease) on bilateral deciduous tooth emergence in children.
Holman DJ, Jones RE (2003)
Measuring developmental noise in bilateral traits. Human Biology
Association, Tempe Arizona. April 25-27. Abstract: American Journal of
Human Biology 15:266.
This site is best viewed with