 Model organisms are central to contemporary biology and studies of embryogenesis (Ankeny and Leonelli 2011; Steel 2008; Bier and McGinnis 2003; Davis 2004). Biologists utilize only a small number of species to experimentally elucidate various properties of ontogeny (e.g., C. elegans, Drosophila, and Brachydanio [zebrafish]; see  Figure 5).  These experimental models permit researchers to investigate development in great depth and facilitate a precise dissection of causal relationships. Critics have questioned whether these models are good representatives of other species because of inherent biases involved in their selection, such as rapid development and short generation time (Bolker 1995), and problematic presumptions about the conservation of gene functions and regulatory networks (Lynch 2009). For example, C. elegans embryogenesis is not representative of nematodes in terms of pattern formation and cell specification (Schulze and Schierenberg 2011) and zebrafish appendage formation is a poor proxy for the development of appendages in tetrapods (Metscher and Ahlberg 1999).