Abstract
Because genes and phenotypes are embedded within individuals, and individuals within populations, interactions within one level of biological organization are inherently linked to interactors at others. Here, we expand the network paradigm to consider that nodes can be embedded within other nodes, and connections (edges) between nodes at one level of organization form “bridges” for connections between nodes embedded within them. Such hierarchically embedded networks highlight two central properties of biological systems: 1) processes occurring across multiple levels of organization shape connections among biological units at any given level of organization and 2) ecological effects occurring at a given level of organization can propagate up or down to additional levels. Explicitly considering the embedded structure of evolutionary and ecological networks can capture otherwise hidden feedbacks and generate new insights into key biological phenomena, ultimately promoting a broader understanding of interactions in evolutionary theory.
Highlights
Within a level of biological organization, units affect each other’s state and activity via various forms of interaction, which we will refer to as connections between units
Research in genetics has highlighted how links among genotypic and phenotypic networks can affect evolutionary change (Stadler and Stephens 2003). We emphasize that these concepts have much broader applicability: 1) networks span within and across multiple levels of biological organization, creating direct and less intuitively— indirect connections between genes, phenotypic traits, organisms, etc., and 2) the fact that units at one level of organization are embedded within units at a higher level results in propagation of network dynamics from one organization level to neighboring levels and beyond
Model systems in evolutionary biology, such as the three-spine stickleback, have been used to investigate a large variety of genetic, behavioral, population-focused, and community-level phenomena that can be integrated through a hierarchically embedded network perspective (Figure 2). Another common example of linkages across levels of organization is the dependence of disease transmission on the network structure of hosts, where the connections among hosts depend on the genes (Radersma et al 2017), phenotypic traits (Mason 2016), and interindividual relationships (VanderWaal et al 2014), and the transmission dynamic plays out at the scale of populations and communities (Penczykowski et al 2016)
Summary
Within a level of biological organization, units (e.g., genes, cells, phenotypic traits, individuals, populations) affect each other’s state and activity via various forms of interaction (e.g., formation of protein complexes, pleiotropy, competition, mutualism), which we will refer to as connections between units. Model systems in evolutionary biology, such as the three-spine stickleback, have been used to investigate a large variety of genetic, behavioral, population-focused, and community-level phenomena that can be integrated through a hierarchically embedded network perspective (Figure 2) Another common example of linkages across levels of organization is the dependence of disease transmission on the network structure of hosts, where the connections among hosts depend on the genes (Radersma et al 2017), phenotypic traits (Mason 2016), and interindividual relationships (VanderWaal et al 2014), and the transmission dynamic plays out at the scale of populations and communities (Penczykowski et al 2016). Thinking about hierarchically embedded networks, where dynamics in a given study system are linked to flow-on changes across the broader environment in which that system is embedded, will encourage a broader and more interdisciplinary general approach to behavioral and community ecology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
