In some ways yes. Humanity has largely left natural selection behind.

How do we define "huge catastrophe"? Something like COVID probably applies and that was probably a wake up call to our fragility. Thankfully vaccines and social measures muted the worst of it, but we still a massive die-off of the old, immune compromised, and genetically unlucky.

I would argue it's less humans we should be worried about and rather things like our crops. If you research monocultures you'll get my point. Humans still have a tremendous amount of genetic diversity, it's unlikely a single plague lets say will wipe us out 100%. But most our major crops are essentially clones of each other. If there arises a COVID for wheat, then yes, if it kills one plant it can potentially eradicate wheat from existence. Look up the Gros Michele banana for information there. That should be a major concern for the future of humanity and something we strive to improve upon.

The adaptations we make using science are just as natural as any other adaptation in any other organism. We're an organism that is clever enough to use science to survive. That's our niche.

Worst case is a pandemic of proportions never seen before. We are already seeing antibiotic resistant strains appearing naturally. If the wrong germs/ bacteria develop a resistance to our most readily available drugs, we could possibly get 150 years worth of die off in a single instance... without the 150 years of reproduction between the resistant survivors that should have occurred.

>So isn't it practically saying no to Natural Selection?

Yes.

>In the case of a huge catastrophe, is humanity gonna be in danger for lack of natural selection?

No. Survivors will find each other.

I heard recently that humans have essentially stopped natural selection in the traditional sense. The idea behind the statement is that we live in a world where people who are not "best suited to the environment" are able to reproduce causing subsequent generations to carry on unhelpful traits, like very poor eyesight. Nature without modern intervention would leave a significant portion of the population in a position to never reproduce allowing for the natural evolution that accompanies advantageous mutations to be passed on through generations. The statement, of course, is a generalization. We have really changed the game. Only in upcoming generations will humans know what the cumulative effect will be. Maybe it should be called "the age of unnatural selection."

First, the hypothesis we use commonly says that natural selection occurs when there is competition amongst the population so if we as a population are competing for these medical advancements then semantically no, evolution is not necessarily stopped because a population gets technology. There are a few faucets to evolution but Darwin's null hypothesis says that if there's competition then there can still be evolution occurring.

Logicaly arguing, at first, any change we make to the environment would be to benefit us more in the short term. Think antibiotics for example. At first we cured lots of diseases but in the future we will have made more deadly ones. The more changes we make to the environment the more it will change and assuming we evolved to do well in that environment, the changes we make might seem good immediately but will have unforeseeable effects which may be more detrimental to us in the long-term. Then again, maybe they wont be because that depends on all the other decisions living creatures are seemingly making in spite or simply jest of the laws of physics.

Still, humans are nature and we are just a small part at that(no matter how much our egos tell us we are the biggest, our egos make us human, they do not part us from nature). A huge catastrophe will cause a special evolutionary event I think termed "bottlenecking" or I don't know the academic terms if you look type in: "bottlenecking, catastrophe and evolution" you should get some textbook material that comes up to explain how that effects the population specifically.

Human ingenuity may be just as natural, but it's benefits are still notably different to adaptations gained via genetic success stories. In evolutionary adaptations, the changes themselves and the benefit gained are inherently linked - a creature develops wings which allow it to fly, an octopus develops the ability to blend it to its surroundings itself which allows it to hide, a giraffe's has a long neck which enables it to reach tall leaves etc. There may be situations where reaching tall leaves isn't actually beneficial (eg in a field with no trees), but the benefit of being able to do so will always exist with a giraffe with a long neck.

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This isn't really the same with human intelligence and ingenuity, which has a much more diffuse relationship between the driver and the outcomes much of the time (and certainly in most of the cases in which people specifically survive when they wouldn't normally, rather than simply elongating or improving their existence). For instance, human ingenuity means we're able to synthesise insulin for the benefit of diabetics, but my possession of human intelligence doesn't allow me to spontaneously create insulin in the middle of a field. I can't cross a furious river simply because humans are capable of building bridges, or survive a fall because we can build parachutes.

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Case in point, we know that people 10,000 years ago were no less intelligent or ingenious, yet lived lives far more ravaged by 'natural selection' than we do today. We benefit from a huge accumulation of knowledge, skills, relationships, transportation, standing-on-shoulder-of-giants research, supply chains etc any parts of which could be potentially be taken away. So the fruits of our ingenuity are huge - leading the OP to ask his question - but if all the libraries and servers were burnt down tomorrow we'd potentially see ourselves back to the living standards of 10,000 years ago, eschewing these huge benefits in a way the giraffe and his long neck don't really have to worry about.

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Humans are evolving right now, and very rapidly.

As you say, we've mostly left disease and predation behind. The main drivers now are mate selection, and population size, which are far higher than they've ever been.

Until relatively recently, people almost always married within their local communities. You had to make a choice from perhaps 10 or 20 people (see Jane Austen etc.). Many people now live in large cities, and those cities are full of people from all over the world. The level of mixing of the gene pool is astonishing, and the number of partners we can pick from is almost unending (see Tinder etc.).

The combination of huge choice and very rapid global mixing means the human genome is shifting very fast indeed.

Writers, especially SF writers, have been talking about the long-term consequences of this change for a 100 years or more. The Time Machine (1895) imagines a future where (spoiler alert) mate selection splits humans along class lines into a useless but beautiful idle middle-class who are farmed for food by the evolved bestial working classes. Brave New World (1931) has a designer future where people have abandoned evolution entirely and degenerated into decadent folly.

Natural selection being a slow process is a myth. It can happen in just a generation - consider a global pandemic (I know - how original), killing 70 percent of the population. You only survive if your genes grant you immunity to the disease. Then bam, natural selection makes all the people in the next generation carry the same gene variant.

It may be worthwhile to note that each of the constructs in your argument have more to them than just failing at natural selection. People are the ones fixing the problems listed in the question, and can trade goods or services like manufactured glasses, eye exams, currency manipulation, and lifting heavy objects for survival needs just like we do today. These skills are not removed due to catastrophe.

The ability to overcome one disadvantage does not guarantee your ability to overcome other difficulties. I’m nearsighted, wear glasses, thus am able to see far. I’m 72 suffered a stroke am hemiplegic, as a result limited mobility so I’m housebound. So I’ve not conquered Natural Selection but merely mitigated its effects.

Humans left natural selection somewhere like 1.5 million years ago when they started cooking food and feeding the weak and sick family members. Not to mention things like agriculture….

It can be said we’ve evolved to adapt to the type of society we are now. If you were a hunter, bad eyesight could get you killed. But we no longer need to hunt our own food to stay fed. But you do need to be able to see so you don’t get creamed by an oncoming car.

Selection is still happening, it just isn't 'natural'. Look at the nations that have a low rate of birth, with many people choosing not to have kids at all. They're basically breaking a chain of evolution billions of years old to an abrupt end by choosing not to pass their genes on.

Whatever factor that is pushing some people to have kids and others to not have any is the evolutionary pressure that is driving whatever form of selection you want to call this.

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