The patella is the largest sesamoid bone in the body. The patellofemoral joint provides an
integral articulating component of the extensor mechanism of the knee joint. A detailed …

According to many biologists, explaining the evolution of morphological novelty and
behavioral innovation are central endeavors in contemporary evolutionary biology. These …

Enhancers are essential gene regulatory elements whose alteration can lead to
morphological differences between species, developmental abnormalities, and human …

Background The correct evaluation of mineralization is fundamental for the study of skeletal
development, maintenance, and regeneration. Current methods to visualize mineralized …

The paper works towards an account of explanatory integration in biology, using as a case
study explanations of the evolutionary origin of novelties—a problem requiring the …

Background Elucidating disease and developmental dysfunction requires understanding
variation in phenotype. Single-species model organism anatomy ontologies (ssAOs) have …

One of the most intriguing questions in vertebrate evolution is how tetrapods gained the
ability to walk on land. Although many hypotheses have been proposed, few have been …

Evolutionary theory has long argued that the entrenched rules of development constrain the
range of variations in a given form, but few empirical examples are known. Here we provide …

Most of Mesozoic bird diversity comprises species that are part of one of two major lineages,
namely Ornithurae, including living birds, and Enantiornithes, a major radiation traditionally …

The origin of birds and powered flight is a classic major evolutionary transition. Research on
their origin often focuses on the evolution of the wing with trends of forelimb elongation …