Surface Area, Volume, and Ratios

I’ve began to have a bit of time for myself again and have been bouncing around with a few ideas related to the use of surface-area:volume ratios to balance chemical processes. Here are a few proposals I’ve come up with:

Effect on Specific Metabolic Pathways: We could have certain metabolic pathways be more or less effective depending on your organism’s surface-area to volume ratio. One thing that somewhat troubles me when thinking about Thrive is the fact that we don’t always have a very concise way to represent certain tradeoffs. For example, nitrogen-fixation seems like something that basically every organism on Earth could benefit from, but there are many complex factors interacting, such as mass, atmospheric tolerances, and etc. which doesn’t make this so. Having certain metabolic pathways be effected somewhat by your organism’s surface-area to volume ratio can be a balancing tool we utilize to somewhat represent why certain prokaryotic pathways don’t carry over as well to eukaryotic scales/niches.

I don’t really have any suggestions as to which metabolic pathways this can be applied to at the current moment. I just think it’s worth bringing up and discussing for future reference and can be an important tool for working through specific concepts.

Effect on Engulfment: A greater surface-area to volume ratio can have a small impact on max-engulfment-size. Rationally, organisms with high surface-area and low volume - “skinnier” organisms - typically have less space to use as storage for their prey (hence white blood cells being rather large).

This can be an additional balancing effect which further emphasizes the importance of having a proper cellular morphology for your niche. Note that because smaller cells will typically have higher SA:V ratios and v.v for larger cells, this effect should be rather small; enough to make “bulkier” cells better at consuming organisms, but definitely not enough to make large cells with high surface area absolutely useless at consuming organisms.

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