Delyle Polet

Five mantises in Dixie cups on a desk

Raising a small army #mantis

First day at a new job in the evolutionary #biomechanics lab at @imperialcollegeldn.bsky.social! We're studying how insect legs gear with size and environment on a @leverhulme.ac.uk grant. Our first subject is here already and I'm excited!

Ah, yes. "The" equation

I think they knew...

Comb Jellies are one of the most sci-fi creatures in existence

BREAKING: Scientists are staging a “science fair” in the lobby of a Congressional building to tell elected officials about the critical knowledge the US will lose because their research grants have been canceled.

Figure showing an arm moving from a flexed to extended posture with elbow movement, and a corresponding simplified model. Line charts show variations in Hill-type and activation parameters explored in the study

New preprint, perfect reading for #SEBconference travel

We simulate how age-related changes to muscle affect point-to-point movement.

Reductions in force, velocity and activation independently reduce performance, but deactivation and stiffness interact!

doi.org/10.1101/2025...

#biomechanics

"Ahh, feels good to submit that preprint!"

Predatory journals: "Greetings of the day!"

#AcademicSky

A well-overdue study to evaluate an equation used by ~everyone in fossil trackway studies (including me). Good job to @peterfalkingham.com and team!

Scorpionfly, from https://commons.wikimedia.org/wiki/File:Skorpionsfliege_Panorpa_communis_male_full_(cropped).jpg by Richard Bartz 2008 CC-BY 2.5

Mecopteran snoots are in the uncanny valley of cute and freaky

When you get an unexpected printer error, ask yourself: do you live with a three-year-old?

YouTube video by Wiley Sneak Mr Incredible learns the truth about floating point numbers meme

youtu.be/FnZhbaDRg54?...

Which border? Mexico? Because Canada is dealing with its own funding issues, and the government has capped international students. There isn't funding or housing available for another big university.

Golden-bloomed grey longhorn beetle on a leaf

Golden-bloomed grey
longhorn #beetle (Agapanthia villosoviridesces). Unlike most longhorns, they develop inside herbaceous plants (Hertfordshire, UK)

Again, we're running the 1st ever virtual international conference on vertebrate morphology (ICVM) this August 7-10: www.isvm-icvm.org/icvm-2025
Abstracts are due 26 May (12 days)!
Of course you can just register and not submit abstract(s).
~3 days of great talks, posters, keynotes and more!

A Chinese giant salamander facing the viewer

'Professor Lew' showing off at the London Zoo on Sunday @zslofficial.bsky.social #amphibians #salamander

"History is new, prehistory is newer, #paleontology is newer still"

- @johngreensbluesky.bsky.social "Anthropocene Reviewed"

It's easy to forget just how recent much of science is

Cornicle - Wikipedia

Ahh, TIL about aphid cornicles. A response to the nearby predator perhaps?

en.wikipedia.org/wiki/Cornicl...

What's going on here?

Singlefoot in lateral sequence #locomotion

You're right, a weasel would have a stronger bite than a scaled down fox with the same body mass

The point is just to be clear how you're comparing between sizes, or else risk misunderstandings where people come away with false conclusions

That would be great, thanks!

Do you have any video of them walking about on lightsheets? I study gaits and I'm interested in how they walk

What do you mean when you say "bite efficiency"?

When researchers say "higher force for their size", they really should clarify, because "force" and "size" are different measures. Is it force per body mass? Force per skull length? Force per (body mass)^(2/3)? These are all valid ways of calculating size-specific force, but give different answers!

I love this diagram- it gives a really intuitive and visceral sense of how leverage modifies bite force.

The caption is misleading, however. Relatively shorter jaws don't transmit more power (generally). And a scaled-down fox would be stronger anyway (in a force/mass sense) b/c square-cube law

Photo of two ants facing each other on a clean white background. The ant at left is orange and massive, with a head that's nearly as big as the rest of its body, and small black eyes set low on its face near its mandibles. The ant at right is smaller, black, shiny, and slender.

Pheidole militicida desert big-headed ant sisters. Major workers (left) and minor workers are set on different developmental trajectories by environmental stimuli as larvae, and mature to perform different roles in the colony. Arizona.

There is no trade-off between speed and force in a dynamic lever system | Biology Letters Lever systems within a skeleton transmit force with a capacity determined by the mechanical advantage, A. A is the distance from input force to a joint, divided by the distance from the joint to the o...

PS: questioning force-velocity tradeoffs (FVT) is not new, but it can be controversial. For an interesting back-and-forth, see
McHenry: There is no FVT doi.org/10.1098/rsbl...
Arnold et al: There is always FVT doi.org/10.1098/rsbl...
McHenry & Summers: FVT not absolute doi.org/10.1098/rsbl... [9/9]

diagram showing energy flow for a muscle contracting against a constant external force

So if G is too small, you lose work to external sources, and if G is too large, you run into force-velocity limits. To maximize velocity output, there's a theoretical optimum... and for more on that, see doi.org/10.1093/icb/... [8/9]

So why don't jumping animals all have large G? In this problem I was cheeky and said to *ignore* muscle force velocity properties. But if G is too high, the muscle will hit Vmax and can't do any more work. [7/9]