My very first contribution to the collected sum of human knowledge has just been published in the Journal of Evolutionary Biology. The paper is called: “A Dynamic Framework for the Study of Optimal Birth Intervals Reveals the Importance of Sibling Competition and Mortality Risks” and you can read it online or download a PDF. I’ll talk about the main results in this post.
The last time I played basketball was around my friend Peter’s house. We were maybe 15 years old and became distracted by pigeons having sex on the garage roof. I am the kind of human who associates dunking with Rich Tea biscuits and dribbling with sleep. With these caveats, I will talk to you now about basketball.
The egg that eventually became you once lay in your grandmother. This giddy fact(oid) happens because, in the womb, women develop all the eggs they will ever use. The supply gradually declines through the years to the point where no more eggs remain, no more children can be sired: menopause.
But why should fertility grind to a halt several decades before the body gives out? Why lose the ability to reproduce? If life is all about making babies and turning them into baby-making machines themselves (speaking biologically, not philosophically), why run out of eggs but carry on living?
On Denmark’s island of microbreweries, I learnt how to avoid death.
From birth, all the eggs a woman will ever get are stored in her ovaries. Her stock of eggs diminishes throughout life – some mature during ovulation, while others die as a kind of collateral damage, spurring the process along. Her cache dwindles until too few eggs remain to maintain fertility. This point is menopause and it is inevitable.
This week in BioNews, I report on a study showing mousy evidence that genetic mutations inherited from mother may speed up ageing.
Mitochondria are powerhouses, batteries, factories. They provide energy to the cells in your body and without them, you die. One of the cool things about these little bean-shaped organelles is that you inherit them from your mother, not your father. Another cool but slightly scarier fact is that their DNA mutates faster than the DNA in the nucleus of a cell. This means your mitochondria can be prone to accumulating damage throughout life, which may in turn contribute to the ageing process.
The researchers in this study found that mice who inherited already-mutated mitochondrial DNA from their mothers aged prematurely compared to other mice. Have a read.