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.
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Sex is *observed* at birth by “reading” external genitalia, which is a remarkably sensitive marker of sex. Sex is also now routinely observed in utero, again by “reading” external genitalia and, increasingly, by DNA analysis.
@RealTayChaTLC The definition of female is: of or denoting the sex that can produce large gametes.
This not a matter of *observation*, this is a matter of *definition*.
@RealTayChaTLC Very few animals and no plants menstruate, yet females exist across almost all complex life.
We do not become men at menopause. We certainly don’t “revert” to men, which implies we were men at some point before menopause. Maybe you think we are men before menstruation?
Across the natural world, male and female are defined by reproductive function, describing the contribution of small gametes (like sperm) or large gametes (like ova), respectively, to the next generation.
In healthy humans, there are two anatomical body types, each corresponding to one of the two reproductive functions. That is, in humans, there are two sexes.
In utero, males and females develop sex-specific primary characteristics pertinent to function during reproduction.
Healthy male anatomy comprises testicles, internal genital structures like the vas deferens and an external penis and scrotum.
Here is a graphic of changes in muscle and strength in transwomen pre- and post- testosterone suppression (12+ months), compared with baseline metrics from demographically matched females.
The original data is presented in Hilton and Lundberg, 2021 (Table 4).
The graphic was created by me for a policy paper I coauthored with Professor Jon Pike @runthinkwrite and Professor Leslie Howe @usask for the Canadian think tank The MacDonald Laurier Institute.
I recently tweeted about people who think I believe humans are asparagus.
This bad faith take stems (ha ha) from an analogy I’ve used to illustrate that the phenomenon of male/female is not limited to the constructions of the human brain.
Like many plants, and like humans, (some) asparagus strains are dioecious - they exist as individuals male and individual female plants. In animals, we call this set up ‘gonochorism’.
Asparagus can reproduce via the fusion of one small and one large gamete (sometimes, they reproduce asexually).
Biological convention denotes the plant morph producing the large gamete, found in the ovules, as ‘female’.
Systematic differences between the two sexes of a gonochoristic species of a physical characteristic (or set thereof), not including reproductive anatomy.
Some sexually dimorphic characteristics are non-overlapping (e.g. deer antlers) while some are very overlapping (e.g. human height).
The extent of overlapping observation/measurement is irrelevant. The only requirement is a robustly-detectable difference between sexes.
Many female humans are taller than many male humans, yet the population descriptions of height in humans consistently reveal that males as a sex class are taller than their demographically-matched female peers.
Height in humans is a sexually dimorphic characteristic.
@xandvt@MumpGorithm@refined_devon@BBCMorningLive@BBCiPlayer I am honestly appalled by your behaviour here. You are a medic and a public communicator, and you seem unable to use basic and commonly-understood words when discussing concepts like population health screens.
@xandvt@MumpGorithm@refined_devon@BBCMorningLive@BBCiPlayer The WHO make it clear that an ethical population screen uses clear language that will maximise capture of the target demographic. Who are the target demographic for prostate screens?
@xandvt@MumpGorithm@refined_devon@BBCMorningLive@BBCiPlayer To define the population demographic for prostate screening as ‘those with prostates’ lacks any explanatory value. It’s a linguistic dead end. Replace ‘prostate’ with a less well-known structure, and then consider how effective a screening campaign will be….