this post was submitted on 19 Jun 2025
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Who writes this stuff?
I had to scroll through 2/3 of the article to find the (meager) definition of the rule being discussed.
High school writing assignments... Wait, no, grade school assignments taught to define the subject first, to make the remaining discussion meaningful.
This was clearly written for the average reader, not people within the community studying sharks (or other animals), so assuming people know this rule is a major oversight.
Why then, did they "bury the lede"? Because they had other points they wanted to make before providing the reader the necessary context.
Ten paragraphs in they state:
So they still haven't explicitely stated this 2/3 rule, but I'll infer the rule predicts animals (all animals? Or just aquatic vertebrates?) body size is constrained by a rule that surface area is ~67% of body volume (they didn't even explain it that simply, instead using "raised to the power"). Can they be any more obfuscatory?
Why would you ever write it this way for non-scientist discussion?
It's even worse because that relationship is already called the square cube law. It's not a fixed percentage. Raising it to the power of 0.67 is the same as squaring it and then taking the cube root. So if volume increases by a factor of 8, you'd expect surface area to increase by a factor of 4. If volume increases by a factor of 27, surface area should increase by a factor of 9.
It's always true for any object that maintains its exact shape while increasing or decreasing in size, but it also tends to apply to animals across different shapes because of gravitational and oxygenation constraints. It's why we don't have any animals with proportions like a sheet of paper standing on end.
The funny part to me was where they say "Sharks follow expectations, this changes everything!"
Misuse of the word "theory" didn't sit right with me either.
Phys.Org is a mixed bag in the best of days.