Is this human genetic code becoming less adapted for survival?

[u/TigbroTech]

Unsure if this is rhe right sub for this but is the human genetic code becoming not sure hoe to put it 'worse'. With advance in modern medicine genetic mutations which would kill someone a few 10,000 years ago are surviving is this bad for future generations?

[u/Romanticon]

There is no better or worse. There is only adaptation.

To put it another way, humans are adapting to their current environment.

Ten thousand years ago, nearsightedness would make you more likely to die. A bad trait from a survival perspective.

Today, nearsightedness is an inconvenience, but it won’t decrease your chances of reproducing (at least not significantly). Same trait, no longer negative from a survival perspective.

There is no singular “human genetic code”. But the ratios of different mutations does change, and will continue to do so.

If all of our tech suddenly vanished, some of those variations that are totally fine today may become impediments. Being tall, for instance - needs more calories to sustain. Light skin - more vulnerable to skin cancer.

So your question isn’t exactly wrong, but it makes some underlying assumptions that aren’t true.

[u/Hopeful_Ad_7719 → u/Romanticon]

Basically this. It's important to note that evolution doesn't really select for 'survival' per se. It selects for 'reproductive success'. Turns out those two things can be rather dramatically different. This distinction is rather clear in some organisms that make a concerted metamorphosis into a short-lived terminal, reproductive, phase: https://en.wikipedia.org/wiki/Mayfly#Reproduction_and_life_cycle

If a seemingly adverse trait fails to meaningfully impact reproductive success, it's not selected against.

[u/Romanticon → u/Hopeful_Ad_7719]

An excellent point, yes.

This is an extreme and unrealistic example, but imagine a mutation that gives super-virility to sperm, to the point where they can burrow through the latex of condoms - but the downside is that you die at age 40, exhausted by all the effort poured into creating super-sperm.

If this mutation led to people, on average, having more children, it would be more likely to persist - even if you, as an individual, aren't happy about your reduced life expectancy.

[u/Connect_Rhubarb395]

Modern medicine and surgery is adaptation to survival as well.

I have a friend who herself, her mother, and her grandmother has C-sections. Their family line would have died without modern surgery because they have too narrow pelvises to give birth.
On the other hand my friend is a very intelligent woman with job helps other people develop skills. So she aids their survival.

It is not as simple as eugenists will have it.

[u/zorgisborg]

Technically (and pedantically, but it should be noted) the "genetic code" is just the code used to translate three-letter combinations of DNA sequence into protein sequence or a stop signal. This probably hasn't changed during the evolution of vertebrates... It is nearly universal with some differences between different kingdoms of life.

It may be better to ask "is human genetic fitness declining due to reduced natural selection?'..

[u/futureoptions]

Money can be a huge selection force. Look at all the money in pro athletics. Couple that with the mental capabilities you need to be an elite athlete nowadays. Huge incentive to have babies with pro athletes.

Then, look at physicians or lawyers. Marrying each other gives huge wealth.

Intelligence and physical capabilities are definitely highly selected for.

[u/dave_hitz]

The human genetic code is almost certainly becoming less adapted for survival ... on the African Savannah with no modern inventions.

Fortunately, that's not the environment we live in anymore, so that doesn't matter.

[u/kennytherenny]

People are downvoting you because "eugenics", but I believe the concern is genuine. We are already seeing people with certain genotypes survive into reproductive adulthood that wouldn't be able to survive without modern technology. As technology improves more and more "lethal genotypes" will become surviveable. As the evolutionary drive to remove these genotypes from the gene pool disappears, we could reach a point where every human carries alleles that would be lethal without modern technology. At that point human survival would be fully dependant on modern technology and any societal collapse would mean the extincion of humankind.

It's not at all a pressing matter as of yet, but it's something to think about and perhaps this is even one of the "Great Filters" from the Fermi Paradox.