Ok, so I recently turned 29, and I have been feeling the pressure of being almost 30. Mainly the whole, 'settling down and having kids' thing. My biological clock is ticking, and I can hear my uterus screaming 'Bitch! What are you doing! Im growin cobwebs here!'. So when I found an article entitled Fertility decline surprises women over 40, I read it, more out of shock that anyone could not be aware that their fertility starts declining in their mid thirties, and in disbelief that this is what the article was actually about and the headline was misleading. As I read it I found out that yes, there are plenty of women in this country that are THAT uninformed about their bodies. Apparently these are the ones who never got into Sex And The City. Aside from pointing out the obvious, the article did bring up an interesting side note. Women are definitely waiting later in life to have children, be it by choice or economic burden. Now, I know women have always had miracles late in life, after all, women had sex with their husbands well after child bearing years in the days before birth control, and it can happen. But the difference is is that now they are CHOOSING to have a baby late, say in their 40's. They are actively avoiding conception with birth control, and then using IVF to kick start the old rusty uterus into life. With a chemical cocktail, we are reprogramming our reproductive cycles to fit our needs, as modern humans. Which, if you believe in such shenanigans, is what evolution does. So I wonder, if by this man made intervention, we will speed up evolution even more? Specifically, will women evolve to have children later in life faster than normal? Imagine for a second a world without birth control or IVF, but the rest of our advances in medicine and nutrition remained the same. Women would naturally evolve a longer child bearing window as our life expectancies grew, as a matter of fact, we already started, our average menopause age has increased, but very very slowly compared to our life expectancy. 100 years ago, the average age of menopause was 45, but the average life expectancy was only 49. Today the average age of menopause is 51, but life expectancy is 80. That means our childbearing years have raised only 6 years, compared to our life expectancy going up 29 years. (We would also, fyi, be living roughly  into our 300's by that point, but you know, this whole point is hypothetical anyways, and just something off the top of my head, so stop over analyzing it). Ok. Back to our imaginary world. So, in our world that advanced the same as the real world, with the exception of birth control and IVF, it would take us roughly 1000 years to evolve to experience menopause in our 60's, and surely our window of good fertility would expand 10 years along with that, giving us an average age of 45 that our fertility would decline, not 35. But maybe, since not only are we conditioning and preparing our bodies to have babies later than we normally would, but we are also conditioning them NOT to have babies in our earlier years, our speed of evolution will shift, and we will begin evolving our reproductive cycle faster than our life span, bringing our fertile years well into our 40's. But I believe it will work the other way around too, perhaps not lengthening our fertile years, but rather, SHIFTING them from our teens and twenties being our most fertile years and our 30's marking the decline of fertility, to our 20's and 30's being our most fertile years, and the decline doesnt begin till our 40's. The actual process of this taking place totally makes sense on an evolutionary standpoint. I mean, think about it. Most modern societies do not need teenage pregnancies. Even in most third world countries, they wait till the girls are 18 to marry them off. Despite what certain tv shows would have you believe, teen pregnancy rates are dropping, we, as a society, are actively avoiding pregnancy in our teens. So what reason would our bodies have to continue to waste precious eggs? It makes much more sense to evolve eggs with longer life spans, and to not ovulate during teen years, using the teen years as a time to instead grow and mature the body, perhaps even mature the eggs, beginning ovulation in our 20's, therefor making our 20's and 30's our prime times for conception, with our teens becoming a rarity and next to impossible, and our 40's will still be fertile, but will mark the begin of our most fertile years. This also benefits evolution in terms of survival as well. Our ancestors teenagers made the parent who offered their infant the best chance at survival. They were young and strong, capable of providing food, shelter, and protection, while their older counterparts were slower, and weaker. Nowadays, this is no longer true. Our teens now days are most def hampered with a baby, and its our older citizens who are best equipped to raise a strong, healthy, smart baby with a good chance at passing along his DNA with a prime partner. So, Im thinkin, this would probably happen anyways, but I wonder if birth control and IVF are speeding up the process.
This is just something I was sitting around thinking about, and decided to get it off my chest. Im not an expert in any way, I just read a lot, that does NOT mean I necessarily know what Im talking about. Do not take me for gospel, or troll if they have already studied this or something and I just missed that study, but if you have thoughts, or know of any studies on this, please let me know! :D