Will Older Mothers Naturally Evolve?

The current trend of women delaying childbirth until their 30s and even 40s on a regular basis has impacts for society as a whole.

One of these may be that we will evolve to have children naturally at a later age.

Personally, I’m skeptical.

Researchers at the University of Sheffield studied marriage and birth trends since the 18th century and this is what they found:

As a result of this, the natural selection maintaining young-age fertility might weaken and the relative strength of natural selection on old-age fertility could increase, something that could potentially lead to improvements in old-age fertility over many generations.

Now family-building appears to be increasingly postponed to older ages, when relatively few women in our evolutionary past would have had the opportunity to reproduce.

As a result, this could lead to future evolutionary improvements in old-age female fertility.

But a lot of the women who delay childbirth until their later years are using IVF. This means that they are not naturally having children, so their genes will not allow this trend to continue.

Medical interventions (including IVF) have messed with our natural evolution.

Not that this is such a bad thing. I’m happy my mother didn’t die in childbirth and my father didn’t die from asthma when he was a young man.

But I don’t think this trend will be overly drastic.

The current average age of menopause is 51, and the six years prior to this is when fertility is generally at its worst. With the average age of starting a family being at 27, I’m pretty sure the majority of women won’t want to be childbearing for 20 years.

And, in spite of life expectancy increasing, menopause has stayed the same for centuries.

But perhaps they are right and older fertility will improve. Perhaps menopause will start coming later and will be in late 50s or early 60s.

But I wonder what the next stage after that will be? Will women always want to delay longer and have kids later and later? Where is the limit on how old women should be when they stop having children?