Figure 3

Architecture and developmental programming. Normal architecture depends on building layers that are based on both quantity and timing of components with an overall structural size limitation (Panel A). Premature activation of subsequent stages disrupts primary base structure requiring downstream components to fill a space larger than normally required resulting in less complexity (Panel B). Likewise, prolonging production of the upstream components increases their complexity at the expense of downstream structures (Panel C), resulting in a hypoplastic structure similar to that seen in disrupted growth of upstream components.