The developmental process establishes the foundation upon which natural selection may
act. In that same sense, it is inundated with numerous constraints that work to limit the …

Morphological and developmental similarities, and interactions among developing
structures are interpreted as evidences of modularity. Such similarities exist between the …

The trilobite head served multiple functions and was composed of several fused segments.
Yet, the underlying organization of the trilobite head, and whether patterns are conserved …

Serially homologous structures may have complex patterns of regionalization and
morphological integration, influenced by developmental Hox gene expression and …

Batoids (skates and rays) are the most speciose group of cartilaginous fishes. Their body
plan represents diverse ecologies and swimming modes. Early skeletal fossil remains, and …

Phenotypic constraints are ubiquitous throughout nature, being found throughout all stages
of life and at multiple different biological levels including cellular, genetic, environmental …

Morphological integration is the result of natural selection influencing the evolution of
multiple morphological traits simultaneously. Understanding how and why morphological …

The brainstem controls almost all normal functions in the life, such as breathing, memory,
movement, and is closely related to many neurological diseases. Despite the importance of …

Molariform teeth have fascinated zoologists for as long as the field of evolutionary biology
has existed, but few mammalian groups show as much morphological variation as hoofed …

Much of 20th-century biology has been driven by and proceeded through a finer
understanding of biological mechanisms at the level of genes and molecules. These gene …