72

The first example that pops into my mind is Hero of Alexandria. He was close to two millenia early with a lot of his ideas, but it is worth noting that nothing he made became more than a toy. He had great ideas for steam-engines, but without the metallurgical knowledge to make them effective (i.e. having a high pressure), or windmills without the economic ...


64

If the sex is freely available, the men will come (no pun intended) Males are naturally attracted to sex. If sexual partners are easily found and freely available, they will travel. Your problem is actually that women will be left raising the children alone so the society would be better arranged to deal with single mothers than worrying about finding men. ...


52

Not a chance Does your alien even use DNA? Is its biology even remotely similar to that of earth based life? If it is it would be a great surprise as both evolutionary trees will have been completely separate. Vague resemblance between species especially species from different worlds is no guide to their capacity to mate. Vampire bats and black birds share ...


51

Sure why not. There are plenty of toxins out there that are lethal in small amounts. We're already getting pretty good at targeted genetic engineering using techniques such as CRISPR. Given 50 years of technological advancement we should be able to figure out how to engineer wasps to have a more lethal sting. All you'd need to do is work your genetic ...


50

Yes, this is possible and in fact already happens in humans causing apparent infertility in couples (alongside a host of other sexual reproducing organisms). Consider for instance variations in two genes encoding for proteins in the eggcoat, ZP2 and ZP3, and another gene encoding for a sperm protein that latches onto the eggcoat, C4BPA. Each of these three ...


41

TL;DR the greatest risk to a long-lived organism is cancer, when cells start to reproduce incorrectly. To prevent this, not only you need a method to supply fresh stem cells to all organs but also a "check" (almost certainly an enzyme of some kind) to kill off runaway cells, to be replaced by core-produced stem cells. This mechanism does not protect the core ...


39

If the alien is truly alien, not some variant human in space, it is highly unlikely to be able to have children with humans. It would not be like horse and zebra, it would be closer to a horse trying to breed with a tree or a fungus. As such the offspring would basically be a genetically engineered artificial lifeform based on the traits of the parents. Thus ...


38

So two ways I can see. The first is simple selective breeding. Get lots of hornets and sample their venom. Take the ones with the most potent venom and cross breed their lines. In the next generation find the ones with the most potent venom, and cross breed their lines. Continue for 50 years. Having a short maturation period means that you will get a lot ...


38

While you point out there is no genetic testing, & I can certainly understand why that would be the case, Blood typing is a skill that is likely to not have been lost. Specifically because it is so useful to medicine, making possible blood transfusions. It is very true that while it cannot conclusively prove paternal parentage, Blood Types can ...


35

I don't think that, even with artificial insemination techniques, you could successfully repopulate with only 5 men. Check out the math here https://en.wikipedia.org/wiki/Sperm_donation. It takes a man 2-3 days to produce a good sperm sample, but even with IVF you are only going to get a few successful conceptions from each sample. So those 5 men can only ...


35

Yes, but it'd never happen. There's nothing to prevent it, though the chances of it happening in the wild are effectively 0. From each grandparent you inherit 25% of your genes. Your parent inherits 50% and you get 50% of that. Some freakish coincidence could mean that you get the remaining identical 75% from your other ancestors and end up your own ...


34

Yes, species can survive eugenics. Many already have (though admittedly not sapient species). Every single species ever domesticated by humans such as cows, dogs, cats, bees, pigs, chickens, llamas, horses, sheep and innumerate plant species have undergone 'eugenics'. Humans have selectively bred these species for millennia, and they have not died out yet. ...


34

You don't really have a problem (or at least not the one you think you have). The 'standard (literary) solution' doesn't bear much relation to observed reality throughout history. People travel if what they need isn't where they are, it's medieval so travel isn't that easy (takes a long time) so a lot of people won't travel back & will just stay where ...


33

Just DNA? Probably not. DNA in and of itself is just information. It contains the coding for cellular machinery, it is not that machinery itself. In the case of a crash landed ship where all humans have died but left the hull largely intact, then all the bacteria, microbes and fungi would spread out from the hull and start populating the planet. Give it ...


32

One of the first things I would be concerned with is how the people of the world would be made aware that these five men are even alive, much less the only viable sperm donators. We are facing a world that would have lost half of its population and most where most people in high level executive positions would have died. There would most probably be a lot ...


32

Will not happen in foreseeable future Let me show you this XKCD first: [White Hat, holding a laptop, is talking to Megan who looks at her smart phone.] White Hat: Biology is largely solved. DNA is the source code for our bodies. Now that gene sequencing is easy, we just have to read it. Megan: It's not just "source code". There's a ton of ...


29

You can, under these conditions: you are a woman you clone yourself and bear the cloned fetus in your womb your daughter, when reaching sexual maturity, does the same. Your grandaughter will be a clone of your daughter who is also your clone. So the 3 of you have the same genes and are also related.


27

Researchers notes Abstract: Find way to terrorize people for our dark overlord-to-be. Lest we lose our research grant. So we, and our families, will not be used as test subjects by other researchers. Our new intern had an idea with hornets. So now we are going to take an already aggressive and slightly sadistic species and improve on that. Test 1: Failure ...


27

Let's take a stab, and say that your creatures look something like this: Those are pretty dog-like, don't you think? Now, let's look at where that one came from, evolutionarily speaking (its cladogram): That ancestor is Dasyuromorphia, as in The order Dasyuromorphia (meaning "hairy tail") comprises most of the Australian carnivorous marsupials, ...


26

Blood type, there are six alleles for blood type with four phenotypes. Just use a similar plan and make them all co-dominant instead the normal setup (O does code for a protein it just doesn't work). So now you have six genotypes and 6 phenotypes. basically take this chart and ignore the blood type column. so A+O would be its own thing and not the same as A+...


25

Preface This question is very similar (but not identical) to a previous World Builder question (What is the minimum human population to maintain a colony). If you're interested in this question and answer, I recommend reading that question and its answers for additional information. MVP The term you are looking for is Minimum Viable Population. This ...


25

So far as I am aware all venom is created in glands and generally derive from enzymes that already exist for some practical function. A mutation of the code for one of these enzymes is usually the source of poison creation. This article is exceptionally helpful in explaining the evolution of venom. It includes vipers, jellyfish, spiders, scorpions, ...


25

Something similar is possible in humans due to a difference in Rh blood groups. The Rh blood group system consists of 49 defined blood group antigens1, among which the five antigens D, C, c, E, and e are the most important. [A]ntibodies to the Rh(D) and Rh(c) antigens confer significant risk of hemolytic disease of the fetus and newborn. (from ...


25

Genetic no..... Physical yes. Ample food, modern healthcare and clean water means they would be healthier, taller and good teeth. Skin would be paler and less blemishes. A child's access to health and nutrition greatly impacts on height, strength and intelligence later in life. Genetic changes are only really likely if the vault dwellers use genetic ...


24

We can look to sickle-cell anaemia for an example. Three quarters of sickle-cell cases occur in Africa. A recent WHO report estimated that around 2% of newborns in Nigeria were affected by sickle cell anaemia, giving a total of 150,000 affected children born every year in Nigeria alone. The carrier frequency ranges between 10% and 40% across equatorial ...


24

Generally speaking, this genetic thief would die out really fast, or would either be so advanced as to probably not need to use its advanced processing power in this capacity. Compusaur Did I say processing power? Yes I did. Assume we have two creatures with human-level genetic codes: on the low end this means over 20,000 genes. We are uncertain how the ...


24

Because those nucleotides occur naturally. ...probably. We've been finding the building blocks of DNA on meteorites for a while now. According to NASA there's a good chance they occur naturally. The team found adenine and guanine, which are components of DNA called nucleobases, as well as hypoxanthine and xanthine. ...Hypoxanthine and xanthine are not ...


24

I don't see a huge problem here. In medieval times small villiges and towns constantly exchanged brides and grooms to evade degeneration (they didn't knew genetics, but effects of inbreeding are obvious) and manage population density. Two variants are possible. In not-so-religious society: So this particular town would just accept only grooms and provide ...


23

What you describe is very much a social contract, so the answer is 100% dependent on your story. You pick the answer you want, and you can build a society that leads to that answer. This is especially true since, given the way reproduction is done, this society has little to do with modern society. Edit: So this answer is popular, so I'm loathe to delete ...


23

Since you are creating a post-apocalyptic (and if that apocalypse was either nuclear or biological in nature), the genetic proof you are looking for might be a mutation which is not currently present in the human gene pool. Look around the animal kingdom for examples of biologically possible traits. Perhaps something from our genetic neighborhood, like a ...


Only top voted, non community-wiki answers of a minimum length are eligible