Sex Ratio at birth

[ArabellaScott]

https://www.bbc.co.uk/sounds/play/m001qw4s

Very interesting.

In general, 54% of babies born are male, but more die young.

The hypothesis about spikes in the birth of boys is the 'returning soldier' effect - more boys are born at the end of wars.

Oh that looks fascinating. Does it cover other population wide effects on baby sex ratios? I remember being told that more girls are born to relationships that do not last, for example. But I don't know the source.

It's a fascinating listen. But they did stress that at an individual level it didn't make a huge difference as to when in the cycle you have sex, the effect was only seen at population level

How interesting, thanks for the link!

I do find it amazing that the population mix is approximately 50:50 male to female - that’s quite the feat when you take all the variables into consideration.

Not so much, the end conclusion was that when people are having MORE sex, there is a likelihood of conceiving earlier in a woman's cycle, which gives a very slightly greater likelihood of having a boy. As noted above, this is tiny but has an impact at population level.

I remember being told many years ago in A level biology that it was because the male sperm swam quicker because they were smaller because of the Y, which was why there were more conceptions, but also the Y made them genetically weaker, meaning more deaths.

Ah yes - remember this - was told that young males' tendency towards riskier behaviour evened it out.

This programme said it was more that immunity is less strong in males; male infants are more susceptible to illness.

The pattern of conclusions recorded differs between males and females. Males accounted for 57% of deaths reported but 64% of all conclusions recorded in 2022; this suggests that males are more likely to die in circumstances that lead to an inquest.
https://www.gov.uk/government/statistics/coroners-statistics-2022/coroners-statistics-2022-england-and-wales#:~:text=In%202022%2C%20the%20most%20common,suicide%20(4%2C904%20or%2014%25).

I can't find anything with both age and sex on it atm. Covid brain is getting in the way.

(Treasure Trove is further down - nice to see The Detectorists are doing well in E Anglia 🎉)