Physicists at Roskilde University in Denmark have shown that a single equation correctly describes the frequency of wing and fin strokes for a wide array of flying and swimming creatures, including birds, insects, bats, and whales.^1,2 They used a technique called dimensional analysis to show that if one divides the square root of an animal’s mass by the surface area of the wing or fin, the result is equal to a constant multiplied by the frequency at which the wing or fin beats or flaps. A plot of wing frequency versus the square root of mass divided by wing area yields a straight line, as shown in the figure above.

Dimensional analysis makes use of the fact that a true physical law should not depend on the units used for a measurement (i.e., English or metric units). Dimensional analysis is a powerful technique that is very helpful for gleaning physics and engineering insights, even when scientists don’t yet have a full understanding of the object or system being studied.

The authors of the paper stated,

The argument is that – like the frequency of walking – the wing-beat frequency is largely determined physiologically as the natural (resonance) frequency of the wing, where the energetic cost of the flapping movement is minimized. ² (Emphasis mine.)

But making machines energy efficient is something that engineers do. The fact that such a wide array of swimming and flying creatures have energy-efficient wing or fin frequencies strongly suggests that these creatures were designed by a master engineer. In fact, a previous engineering study also revealed efficient propulsion design across a wide array of swimming and flying creatures.³ So did these scientists give glory to the Lord Jesus for His engineering handiwork seen in flying and swimming creatures? Sadly, but not too surprisingly, no. Instead they attributed this remarkable result to convergent evolution and natural selection.

Convergent evolution occurs when different species occupying similar ecological niches adapt in a similar way to similar selective pressure....The evolution of the capacity of flight is a classic example of this. Flying insects, birds, and bats – but also the prehistoric reptiles, pterosaurs – all evolved the useful ability to fly.²

Evolutionists usually claim that similar body parts (homology) imply descent from a common ancestor. Yet there are times when similar features are found in creatures which, according to the evolutionary story, did not descend from a common ancestor. This is the case with wings, which supposedly evolved independently in insects, birds, bats, and reptiles. So similarity is evidence for common descent, except when it isn’t. Then it becomes evidence for convergent evolution. Heads I win, tails you lose!

So, according to the evolutionary story, flight evolved independently four times. And not only that, but each time “selection pressures” magically ensured that the flight was energetically efficient!

At the most recent International Conference on Creationism, I presented a paper describing a metabolic scaling theory by physicist Geoffrey West and biologists John Brown and Brian Enquist that has been very successful at explaining design features of the mammalian circulatory and respiratory systems.^4,5 Despite “throwaway” claims in their papers that optimization of these features was achieved by natural selection and evolution, in reality, evolutionary thinking contributed nothing to their theory. West et al.’s theory assumed that respiration and circulation are energy-efficient and determined what mathematical conditions need to be met to ensure this. Lo and behold, these conditions were found in creatures living in the real world!⁵ West et al. also derived an equation that describes how body mass in an organism varies from birth or hatching to adulthood.⁶

There is another reason this story may be of interest to creationists. Similar to what these Roskilde University physicists did, a physicist named Andrés Escala (University of Chile) has used dimensional analysis to deduce a relationship between rate of oxygen consumption, temperature, body mass, and fundamental biological frequencies such as heartbeat.^7,8 He has also expressed this relationship in terms of lifespan and time to reach maturity.⁹ Escala’s work is not as well-known as West et al.’s theory, but it has the advantage of being dimensionally consistent, which must be true of any genuine physical law.

Organism longevity is a complicated subject, and there is much about it that scientists don’t understand. But dimensional analysis is very helpful in precisely those kinds of situations. Since the work of Escala and West et al. involve lifespan duration and ages at maturity, they may lead to insights that could help explain the amazing longevity¹⁰ that characterized humans (and likely animals, too,^11,12) in the pre-Flood world.

References

1. Flapping frequency of birds, insects, bats and whales predicted with just body mass and wing area. Phys.org. Posted on phys.org June 5, 2024, accessed June 11, 2024.
2. Jensen, J. H. et al. 2024. Universal wing- and fin-beat frequency scaling. PLoS ONE. 19 (6): e0303834.
3. Guliuzza, R. J. 2014. Reverse Engineering Reveals Ideal Propulsion Design. Creation Science Update. Posted on ICR.org March 14, 2014, accessed June 13, 2024.
4. Hebert III, L. 2023. Allometric and Metabolic Scaling: Arguments for Design . . . and Clues to Explaining Pre-Flood Longevity? Proceedings of the International Conference on Creationism. 9, article 18.
5. West, G. B. et al. 1997. The origin of universal scaling laws in biology. In Scaling in Biology. J. H. Brown and G. B. West, eds. Oxford, UK: Oxford University Press, 87–112.
6. West, G. B. et al. 2001. A general model for ontogenetic growth. Nature. 413 (6856): 628–631.
7. Escala, A. 2019. The principle of similitude in biology: From allometry to the formulation of dimensionally homogeneous ‘laws’. Theoretical Ecology. 12 (4): 415–425.
8. Escala, A. 2022. Universal relation for life-span energy consumption in living organisms: Insights for the origin of aging. Scientific Reports. 12 (1): 2407–2414.
9. Escala, A. 2023. Universal ontogenetic growth without fitted parameters: Implications for life history invariants and population growth. Theoretical Ecology. 16 (4): 315–325.
10. Hebert, J. ICR Research is Revealing Evidence for Pre-Flood Longevity. Creation Science Update. Posted on ICR.org October 30, 2023, accessed June 11, 2024.
11. Hebert, J. 2024. Oysters and Pre-Flood Longevity. Acts & Facts. 53 (5).
12. Hebert, J. 2024. Giantism and Delayed Maturation in Fossil Sharks: Evidence for Extreme Longevity? Creation Research Society Quarterly. 60 (4): 267–283.

Stage image: Universal wing-and fin-beat frequency scaling
Stage image credit: Copyright © Jens Højgaard, Jensen Jeppe C. Dyre, Tina Hecksher, 2024. Used in accordance with federal copyright (fair use doctrine) law. Usage by ICR does not imply endorsement of copyright holder.

* Dr. Jake Hebert is a research associate at the Institute for Creation Research and earned his Ph.D. in physics from the University of Texas at Dallas.