Talk:Population
Open Issue: Wikipedia gives 500 - 1000 individuals to be a minimaly viable population: Minimum viable population
- I was under the impression that a minimally viable gene-pool consists of 40 unrelated individuals - Jarogers2001 01:07, 21 October 2008 (UTC)
- The number may depend on wether the colonists are preselected to exclude known genetic diseases and disorders. Frozen embryos could be sent with the colonists to provide added genetic diversity without the extra space (aside from refrigeration/support - still a lot less than the equivalent number of full grown humans). Aside form the outstanding moral/ethical stickiness, people may be willing to donate "extra" embryos from fertility treatments, or donate them outright. --Laertes 01:24, 21 October 2008 (UTC)
- I thought a minimally viable population was around 100. T.Neo 07:07, 21 October 2008 (UTC)
- I went ahead and asked an expert. This is what I found out: There is no definite minimum viable population, just a survivability curve based upon the number of individuals of a species spread out over an arbitrary geographic area. The larger the area and higher the population, the higher the statistical probability of survival. Genetic diversity also affects the curve. Thinking the other way: viability decreases as geographic spread, genetic diversity, and population decrease. Geographic spread will avoid taxing the local (in this case Artificial) environment and will ensure survival should something happen to one or more habs/settlements. Instead of bringing embryos, I suggest sperm as it is easier to implant and stores can be diluted (unless we develop some form of artificial womb). - Jarogers2001 06:32, 26 October 2008 (UTC)
- Cryopreservation of fertilized eggs and (microscopic) embryos is common practice in human reproduction medicine. In Germany the cryopreservation of embryos is prohibited by law, but cryopreservation of fertilized eggs is done in a nearly industrial scale. The effort for storage of cryopreserved sperm and cryopreserved embryos is the same. Combined with the implantation of sperm, the implantation of such an embryo is done by a very similar process: The embryo is lifted by a pipette off the petri dish, and then it is inserted into a woman's womb. All in all, this is state of the art. -- Rfc 10:46, 26 October 2008 (UTC)
- Note that sperm can be implanted with something as simple as a turkey baster and tube, and does not require hormone treatments before implantation. It's a quick, low-tech solution that is common practice in livestock. - Jarogers2001 21:31, 28 October 2008 (UTC)
- Hormone treatments are not necessary for implantation of an embryo, either. Hormone treatments are necessary to produce embryos before cryopreservation, which is done on Earth, before the transport to Mars. -- Rfc 20:11, 29 October 2008 (UTC)
- Cryopreservation of fertilized eggs and (microscopic) embryos is common practice in human reproduction medicine. In Germany the cryopreservation of embryos is prohibited by law, but cryopreservation of fertilized eggs is done in a nearly industrial scale. The effort for storage of cryopreserved sperm and cryopreserved embryos is the same. Combined with the implantation of sperm, the implantation of such an embryo is done by a very similar process: The embryo is lifted by a pipette off the petri dish, and then it is inserted into a woman's womb. All in all, this is state of the art. -- Rfc 10:46, 26 October 2008 (UTC)
- I went ahead and asked an expert. This is what I found out: There is no definite minimum viable population, just a survivability curve based upon the number of individuals of a species spread out over an arbitrary geographic area. The larger the area and higher the population, the higher the statistical probability of survival. Genetic diversity also affects the curve. Thinking the other way: viability decreases as geographic spread, genetic diversity, and population decrease. Geographic spread will avoid taxing the local (in this case Artificial) environment and will ensure survival should something happen to one or more habs/settlements. Instead of bringing embryos, I suggest sperm as it is easier to implant and stores can be diluted (unless we develop some form of artificial womb). - Jarogers2001 06:32, 26 October 2008 (UTC)
Once the embryo is implanted, it will do nothing but consume resources for the next plus-minus 10 years. In contrast to this, adult colonists can start working almost immadiatly upon arrival. What about implanting two embryos at a time? Would this be a good idea or am I talking nonsense? T.Neo 07:18, 27 October 2008 (UTC)
- Implanting two or three embryos at a time is common practice, as well. Statistically, one out of 6 implantations are successful. -- Rfc 19:57, 28 October 2008 (UTC)
Aside from "assisted reproduction" methods discussed above, I could see the need for arranged marriages (or at least planned reproduction) especially within low population settlements. It would be preferrable to find a mate from another, unrelated settlement. Such ideas are hard to accept for those from a "modern" western culture, but are common among many other cultures in the world. --Laertes 00:42, 30 November 2008 (UTC)
