This is your regular reminder that I am not an entomologist and I do not study beetles.
My handle is derived from a quote about creationism and I research human genetics and genetic disorders, including one that kills males.
Here is a motor neuron I grew in a dish.
I do not study cool things like…
Jewel beetles. Studies of their iridescence (like liquid crystals) has helped paint chemists. It’s also surprisingly good camo (expt: attach bright or dull wings to mealworms and see which get eaten by birds…).
Dung beetles. They roll crap around all day. Their immune systems are a source of some interest.
Whirligig beetles. They have a tight turning circle for an inflexible body. Boat people are intrigued. London cabbies look smugly on.
Bombardier beetles. Toxic explosions of liquid from their tummy. Apparently, they might inform the design of fire extinguishers and nebulisers, but we’re all thinking jet packs, right?
Namibian desert beetles. How we might harvest water from thin air. Note: not by licking them. I don’t think.
Spanish fly. Beetlejuice. Juice for men, if you get my meaning.
And a key gene in beetle sex determination is called doublesex.
Males have a long form and females have a short form of doublesex.
The short, female form is made by the action of a protein called transformer.
Or TRA for short.
That is, TRA can convert male>female.
And a final beetle sex fact.
A male flour beetle will ‘mate’ with another. Maybe so when this second male mates with a female, he actually contributes the first male’s sperm. Or the first male is clearing out the old before he finds his own female.
Anyway, here you go.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
Let’s have a think what hormone categories looks like. And let’s assume that @neiltyson is considering a high/low T category. This has also been proposed by @AliceDreger
The proposal only works if you don’t deny evolution and sexual selection. Remarkably, there are academics who argue there is no biological basis for why males run faster than females. While it is plausible ongoing underinvestment in female sport means female athletes have not yet reached their full potential, it is frankly ridiculous to think this can explain the entirety of the performance gap.
See Sheree Bekker et al for more details on why, because one time, this one female figure skater won a medal, Usain Bolt should be allowed to race against females.
The proposal only makes sense if we recognise that the action of T on a body gives advantage in sport. This is by no means universally-accepted. Many humanities types argue T is not a key part of sports performance, citing males with low T and people registered as female with high T. Even though both phenomena are explicable by factors like illness, doping and male DSDs, still this argument persists.
See Veronica Ivy, Katrina Karkazis et al for why we should pretend that the stupidly high prevalence of weightlifting males with low T is not because they have just finished an off-period jacking up.
Why male advantage in sport is not a social construct: height.
Height is a key difference between males and females. What is nature v nurture? What does that mean for sport?
Bigger skeletons are most obviously driven by longer bone growth. Key bones like those in your thigh (“long bones”) grow from their end to get longer, making you taller.
The site of bone lengthening is called the “epiphyseal plate” or “growth plate”. Here, cells divide/enlarge, making new tissue that pushes the bone ends apart. This tissue calcifies and is replaced by bone, leading to lengthwise growth.
Let’s set a concrete example: the 10 second barrier (100m sprint).
Wiki - allowing for small errors - tells me that around 200 male sprinters have broken it. We know, of course, that no female sprinter has been close (Flo Jo record 10.49s).
For the following, I’m going to ignore the premise that humans might be close to biomechanical limits over a 100m sprint. It’s just an illustration.
If we follow world record progressions, we see trends (not just in sprinting, the graph below is from a swimming event).
As the latest on Olympic boxer Imane Khelif is reported, a diagnosis of 5ARD is almost certain. I and others first raised the likelihood of this DSD a few months ago.
Understanding how the developmental biology of DSDs interacts with sports categorisation is crucial.
I spoke about this with Andrew Gold during the competition:
And I recently gave a talk at a meeting, on DSDs, male advantage and sports categorisation. I will add some slides below.