Andrew H. Lee


I am an evolutionary morphologist with expertise in bone histology, biomechanics, and growth. This expertise gives me a unique perspective that integrates form, function, and time. With this perspective, I seek to understand why skeletons have certain microscopic features.

By using the annual growth lines preserved in dinosaur bones to estimate growth rates, my work shows that large dinosaurs matured about five times faster than living reptiles scaled to comparable size. Even small dinosaurs grew about 40% faster than living reptiles. A potential ecological advantage of rapid growth is the increase in lifetime reproductive success. These findings clarify how dinosaurs were successful for 150 million years as well as the precedent for rapid growth in their descendants, birds.

More is known about bone histology in extinct species than in living ones. Therefore, my current research focuses on living species. I am currently testing whether laminar bone is an adaptation to flight. Laminar bone is thought to resist twisting loads and is prevalent in some of the wing bones of birds. But it is absent in bats. The absence of laminar bone in bats is best explained by relatively slow growth compared to birds. This work suggests that growth is an important constraint on wing bone histology. To test this further, my students are tracking how laminar bone develops in the wings of growing birds. I believe that this ontogenetic approach is a powerful tool when testing for adaptation.

Evolutionary Studies Histology Paleontology Zoology

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Work details

Associate Professor

Midwestern University
Department of Anatomy

PeerJ Contributions