Mueller Home Page
mueller picture
Research Interests
Aging and Mortality Plateaus
Several laboratories have documented the decline in age-specific mortality at very advanced ages for several insects including Drosophila. It has also been suggested that these observations can not be explained by existing evolutionary theories of aging. My colleague, Michael Rose, and I have studied this problem theoretically (#46, see C.V.) and demonstrated that there are versions of both the antagonistic pleiotropy hypothesis and the mutation accumulation hypothesis which have as natural predictions mortality plateaus. We tested these theoretical predictions with experiments using populations of Drosophila selected under different demographic regimes. The results from this research has been consistent with our evolutionary theory (#68). I have also worked on statistical properties of heterogeneity theories (#72), in the hope that these theories can be made testable. More recently our evolutionary theory of late-life mortality has been extended to female fecundity (#'s 80-82, 85). This research is now summarized and expanded in my new book, Does Aging Stop?
Density-Dependent Natural Selection
A long standing interest in my laboratory has been the role of population density in life history evolution. This research is conducted on laboratory population of Drosophila melanogaster. Several studies have documented a trade-off in the evolution of density-dependent population growth rates (#'s 2 and 29). Many of the experimental results that we have obtained from these populations are reveiwed in publication #50.
Forensic DNA Typing
The use of DNA typing techniques has associated with controversy over how to properly report the weight of a DNA match. My own point of view is that ultimate weight of DNA matches ought to be no higher than the known rates of laboratory false matches. There have now been a sufficient number of false matches made that it is clear that these errors happen on the order of one in hundreds to one in thousands not one in billions. Empirical support for some of these positions can be found in a recent paper (#57, see C.V.). Examples of lab errors are given in the "Lab Errors" link on the left. An interesting web site, maintained by my colleague William Thompson can be consulted for additional information on DNA typing. I have also written about the finding of a large number of matches in offender databases (#94).
Population Dynamics and Stability
Related to my work on density-dependent natural selection has been a long interest in understanding the ecological determinants of population stability. I have developed a detailed model of the dynamics laboratory populations of Drosophila (#21). With this model several natural predictions about population stability emerge, which we have now tested (#38). This work has shown that the stability of Drosophila populations is enhanced when the adults are provided with low levels of nutrition and larvae are provided with high levels of nutrition. We have now completed a very large scale study, to determine if unstable Drosophila populations may evolve life history characters that stabilize the population. After 45 generations of selection the answer appears to be no (#60, see C.V.). We are now pursuing the role of age-structure and migration on the stability of these laboratory populations. Much of this work and other research is reviewed in a book (Stability in Model Populations) written by myself and Amitabh Joshi for Princeton University Press' Monographs in Population Biology Series. Population census and weight data used in chapter six of the book may be downloaded here.
stability book cover
Evolution and Ecology of the Organism
This book, which I wrote with Michael Rose, is a general introduction to Evolution and Ecology. The role of evolution is emphasized throughout the book.
back book coverbook cover
Does Aging Stop?

does aging stop


For more information e-mail L.D. Mueller

(4/15/00) 
Last updated 22 March 2011