Question

I'm looking for examples of organisms (or biological units at some other scale, like cells) whose physical and/or behavioral properties develop differently depending on whether the individual is in close contact with others. In particular, I'm interested in cases where individuals are specialized for fairly narrow functions as part of their usual collective existence (e.g. as animals in a society or cells in a tissue) but develop facilities for more autonomous/self-sufficient operation (possibly including significant anatomical changes) when isolated.

The example that originally came to mind (which isn't really even what I'm looking for) is heart cells that beat together when touching. A slightly better one might be colonial organisms like pyrosomes. I hope there are even better examples in which the solitary form exhibits distinct differences from the grouped one. Are there animals or plants that do this? Microscopic organisms (maybe other zooids)? Thanks in advance.

(Sorry if this question is too vague/abstract. For more context: I'm helping a friend with some nonfiction writing, and we're looking for a metaphor from nature to introduce a passage about how pandemic-related isolation has spurred some people to blossom artistically/intellectually/etc.; it'd be really cool if there were an organism that similarly grows into a new version of itself when separated from its neighbors.)

Answer 1

The cellular slime mold Dictyostelium and the colonial chlorophyte Volvox are instances of organisms that undergo significant changes when shifting between collective and solitary states, highlighting differentiation and specialization depending on environmental and social contexts.

Step-by-step explanation:

The concept of individual development in response to social isolation is fascinating and can indeed be found in nature, offering apt metaphors for human changes during pandemic-related isolation. One such biological phenomenon is observed in the cellular slime mold, specifically the species Dictyostelium. In its solitary phase, each amoeba-like cell operates individually, hunting and consuming prey. However, upon the deprivation of food, these single cells aggregate to form a multicellular 'slug' that migrates collectively, later differentiating into a fruiting body composed of stalk and spore cells, which are specialized for different functions.

Another example can be seen in the chlorophyte Volvox, a colonial organism. Individual Volvox cells can function autonomously, but within a colony, they show differentiation and specialization, with certain cells taking on reproductive functions. These examples illustrate how both cellular and multicellular organisms can exhibit differentiation and specialization as a response to changing environmental conditions or social contexts.