I don't know why you're being so obtuse about this: You don't have to wait until the population is completely inbred and then suddenly have all these babies from the embryos. You could start selectively introducing new genetic material within the first few generations. My point is that if you're bringing along 20k extra people who will make the trip harder, and you're only bringing them along in order to keep diversity, then why not just bring their sperm and eggs instead. Introduce them into the population as you go if you need to, but I don't think people will become crippled by genetic defects after a couple hundred years if you have a few hundred people.

What, did you write the article? Are you offended that someone might disagree?

Yeah, well in a catastrophic case, you might lose the whole ship in any case, depending on the nature of the catastrophe. Hell, what if you had a catastrophe that meant only 150 people survived the trip? I bet those people would wish they had embryos to introduce genetic diversity.

I don't see why you would ignore bringing additional genetic diversity along for the ride, and I don't see why you would have to have the colonists raise "loads of children on the side". Nobody said you would have to implant all of those embryos upon landing and suddenly have a hundred-thousand kids raised by 150 adults. My point was that you could reintroduce diversity over time. Along with everything else, having a load of diverse genetic materials could enable you to monitor the current lack of genetic diversity and choose to implant embryos specifically targeted to fill those gaps.

That's skirting the issue a bit. Whether you officially consider it a separate species, I was thinking it was an interesting question to ask, "How many different animals would you need to bring with you, both different kinds of animals (e.g. species) and how many members of each kind.

Now that's the kind of thinking I was hoping for. How many different diseases would you need? You might have to plan to bring viruses and bacteria that are infectious among many different kinds of animals (i.e. species). Or would you need to plan it out? Is it possible that you'd have to take so much assorted biology that you'd be certain to bring diverse diseases with you anyway?

I agree it doesn't seem possible with current technology, which is part of why I think it's an interesting thought experiment. You might try some different whacky approaches. For example, instead of starting from the smallest possible ship and adding to it until it's self-sustaining, you could start with an example that it known to work-- our solar system-- and take things away until you have the smallest thing that would still work. That is, clearly if you took a planet the size of Earth and with all the resources of Earth, put all of Earth's life on it, and put it in orbit around the orbit of a star comparable to our own, then it would do a pretty good job of sustaining life for a good long time. All you'd need to do then is to shove the star in the right direction to that inertia and gravity would take it along the course to your destination. So do you need the galaxy too, in order to make this work, or is the solar system enough? Do you need the other planets, or could you do it with just the Earth and the sun? If you did it with just the Earth and the sun, could you make the Earth smaller and still have it work? Could you make the star smaller, bring the earth closer? What's the bare minimum for a self-sustaining ecosystem?

I think that this question gets especially important if you want to travel to other star systems or possibly terraform another planet, but it might be a worthwhile thought experiment for the purpose of preserving our own ecosystem. This was, after all, part of why we've tried building enclosed bio-domes.

Why would you possibly need genetic variation from day one? Certainly you don't supplemental genetic variation for at least a generation or two? Like, lets assume the optimal number of people for the trip is 150 people-- is inbreeding going to be a big problem right away in the first generation born on the trip? I don't see why. I would guess that 150 people can have a few generations before it becomes a real issue.

Looking at the graph in the article, with 150 people, you would get about 100 years before the "variation of a hypothetical gene" would drop to 50%. That doesn't seem catestrophic. And you could always have a wide variety of frozen embryos, do regular genetic screening, and introduce embryos with the variations that have "died off" every once in a while. Even with the plan to bring embryos around for genetic diversity, you would have the option of dipping into the embryos before reaching the destination.

Now if we hypothetically come up with all the other technology to make this trip, figure out the practical concerns, and find that it's practical to transport 40k people, then by all means go for it. On the other hand, it's entirely possible that practical concerns would make such a high number difficult or impossible. Along with everything else, since you're going to want to minimize social strife during the trip, keeping it below Dunbar's number might be a good idea.

So overall, I stick with the idea: It would be better to plan to transport a number that would be optimal for making the trip, and then pack other genetic material for increasing diversity as needed.

Well that becomes a very interesting question when you consider the idea of a completely self-sustaining spaceship. Imagine you had to create a spaceship could contain an entire ecosystem ideal for human habitation, surviving indefinitely. What would that look like? How would you keep all the different populations alive, but also checking population growth? And let's ideally imagine that it could keep itself in check without too much intervention.

How many different species of life would you need? How big would it need to be? What kinds of outside supplementation (e.g. sunlight) would be needed?

Don't be a dick. I was exactly pointing out what you alluded to later in your post:

They're talking about the genetic diversity as a long-term issue for sustainable colonization of a planet. A controlled trickle of additional diversity over time would probably give you exactly what you need. The fact that you'll be living in "extreme frontier living" probably means that you don't want to start of with an enormous population right away. So again, you could (and probably should) focus on figuring out how many people are optimal for making the trip and starting the initial colony, and then figure out how to introduce additional genetic diversity once you arrive and establish yourselves.

I think the point was something more like, "We don't need to worry about genetic diversity if we can just pack embryos." That way, you can staff the spaceship with an appropriate number of people for making the trip and establishing a colony, and then use the embryos once you hit the point of needing genetic diversity.

Or pack eggs and sperm, mix as needed. Or just biological samples that can be cloned. Or hell, if we're getting really sci-fi here, maybe we can perform direct genetic manipulation by that point.

That's a fine way of looking at things, but then the most dramatic results you should report are "It appears to be a correlation, but more study is needed." There had better be no attempt to claim a causal linkage.

I think part of the issue there is whether we can have a reasonable expectation that they can reach Mars safely, live on Mars indefinitely, and return to Earth eventually (if they desired). Not a guarantee, but a reasonable expectation. I think that's a great goal for us to be working towards, but I wouldn't expect us to be able to do that yet.

Not quite. It'd be a stretch to argue that the people involved in gay marriage are coming to harm as a result-- though I suppose someone might argue that their souls are in jeopardy or something. However, in the case of these missions, the astronauts are going to die.

Because of this, I think that it would be more comparable to talking about the ethics of assisted suicide, or performing dangerous medical experiments on willing patients. Or even the case in Germany where a man consented to being cannibalized. I'm not equating all of these things, but only pointing out that they're more comparable than gay marriage.

In these cases, we're forced to ask, "At what point do we respect a person's right to cause themselves harm?" If a twelve year old tries to kill himself because his girlfriend broke up with him, we intervene. If a dying 100 year old man says he doesn't want additional medical intervention to prevent his death, we respect that. Somewhere in between, we have to draw a line.

Yeah, I couldn't figure out if the article just wasn't meant for the general public, like maybe "Indie Statik" is only focused on game developers, and unless you were' heavily into that world, you shouldn't bother reading this.

I wondered about that because not only was there a lot of jargon, but there strange and unclear metaphors, and there were references to various things that seemed to assume you'd understand the reference. Half the time, I didn't know what the author was talking about. Maybe someone in the world of indie game development would understand it all?

I may be confused, but... are you questioning the whole idea of hypervisors on servers at all?

There are a lot of reasons for that. One of the simple reasons is that it's cheaper. When you're working in IT, you often have a bare minimum of hardware you have to buy with each server in order to be safe, e.g. dual hot-plug power supplies, hot-plug RAID enclosures and drives, lights-out management, etc. Because of that, each server you buy is going to end up being about $4k minimum, and the price goes up from there. If you have to buy 5 servers, you might be spending $25k even if they aren't powerful servers. However, you may be able to run all of those servers on a single server that costs $10k. In addition to the initial purchase being less, it will also use less power, take up less space, and put out less heat. All of that means it'll be cheaper of the long term. It will also require less administration. For example, if an important firmware update comes out that requires a certain amount of work to schedule and perform, you're doing that update on 1/5 of the servers you would be doing it on. Oh, and warranty renewals and other support will probably be cheaper.

So more directly addressing the question, which I think was, "Why not just buy one big server and install everything on it?" There are lots of reasons. I think the most important reason is to isolate the servers. I'm a big believer in the idea of "1 server does 1 thing", except when there are certain tasks that group well together. For example, I might have one server run the web and database services for multiple web apps, and another run DNS/DHCP/AD, but I don't really want one server to do both of those things.

And there are a few reasons for that. Security is a big one. There are services that need to be exposed the the internet, and then there are services where I don't want the server running them to be internet-accessible. Putting all of those services on the same physical server creates a security problem, unless I virtualize and split the roles into different virtual machines. Or it may be that I need to provide administrative access to the server to different groups of people, but each can't have administrative access to each other's data. Hosting providers are a good example of this: You and I could both be hosting our web application on the same physical machine at the same hosting provider, and we both might need administrative access to the server. However, I don't want you having access to my files and you don't want me having access to yours.

Another big reason you'll want to isolate your servers is to meet software requirements. I might have one application that runs on Windows, but is only supported up to 2008R2. I might have another application or role that needs to run on Linux. I might have a third role where I really want to use Windows 2012R2 to take advantage of a feature that's unavailable in earlier versions of Windows. How would I put those things on the same server without using virtual machines?

Isolating your servers is also good because it tends to improve stability. Many applications are poorly written can cause crashes or security problems, and keeping them on their own VM server prevent those applications from interfering with other applications running on the same physical hardware. I can even decide how to allocate the RAM and CPU across the virtual machines, preventing any one application from slowing down the rest by being a resource hog.

Aside from all that, there are a bunch of other peripheral benefits. For example, with virtual machines, you have more options for snapshotting, backing and replication, restoring to dissimilar hardware, etc. With traditional installs, I need special software to do bare-metal restores in case something goes wrong, and the techniques used in that software often doesn't work quite right. If virtualized machines, I just need the VM's files copied to a compatible hypervisor, and I can start it up wherever I need to. With the right software, I can even move the whole VM live, without shutting it down, to another physical server.

There are probably a few other benefits that I'm just not thinking of off the top of my head.

I would generally disagree. I could see having some weird old piece of hardware that is completely isolated from the internet running an old OS for a good long time simply because there's no reason to upgrade, but then again, 10 years is already a good long time.

Among most users, the problem is usually just poor planning and bad budgeting. Someone spent a bunch of money buying a solution that they then don't have the money to maintain properly. That's how you end with with businesses running internal custom apps that only run on IE6. That's how you end up with businesses relying on some junky old piece of hardware that constantly breaks down and nobody can fix. That's how you end up needing to rebuild your system from scratch because there's no upgrade path-- the upgrade path from v3 to v7 requires you upgrade through v4, v5, and v6, but v4 is completely unavailable now.

If you're spending 50k in hardware this year, you should have an estimated lifetime for that hardware, a maintenance plan for the lifetime of the hardware, and you should be budgeting for the replacement of the hardware once the lifetime expires. I don't have much sympathy for businesses that bought hardware 10 years ago with no maintenance plan or budget for replacements. If you're running your business and you can't afford to maintain and eventually replace business-critical systems as needed, then your business model isn't sustainable.

I'm not a programmer, but it seems to me that different programming strategies are required for different situations. In the case of someone writing a kernel or other low-level code, you may want to optimize the hell out of the code even if it makes things hard to read. The idea here is that whoever is working on the code should have a pretty good idea of what they're doing and could read the difficult code, but performance is among the top priorities. In that case, there is a certain elegance in creating code that's super-efficient even if it's apparently complex.

However, for most other programs I would agree with you-- one of the major priorities should be to keep the code simple and easy to read, keeping in mind that you want it to be as easy as possible for another programmer to come in after you and make updates without breaking anything. In that case, I'd think of "elegant code" as something that does powerful things while being almost transparent to a neophyte.

Even so, it still means that the NSA doesn't just have it sitting on their servers where they can look up the data they promised they wouldn't. They need the approval of the rubber-stamp court, but at least this way they actually need that approval rather than just casually logging into their own servers. I'm not claiming it's sufficient reform, but it would be a meaningful reform. What has been disturbing about the Snowden revelations is not only that they're spying on us without oversight, but that it's apparently also easy for an individual employee of the NSA or even an outside contractor to pull whatever data they want without even the rubber-stamp court approval.