Human evolution IN SPACE

[RyanW]

Originally Posted by Nosforontu

If your initial colonist were selected from Olympic Level Athletes, and the environment of the colony really requires very athletic/fit people to survive then your colony is probably going to have a fairly high preponderance of people with various Athletic Talents.

Note that, from a genetics point of view, "right to breed" is largely equivalent to "ability to survive." This is why many creatures have evolved such elaborate mating displays. It's probably as easy to screen your colonists to prevent those with undesirable traits (perhaps traits useful in initial colonists, but not later citizens) from procreating as it is to leave them behind, though not as socially acceptable.

A eugenics program backed up by real science (and with more practical goals than the mostly racist ones of the early 20th century) could modify the human species more quickly than the conventional natural selection method of shooting DNA at anything that survives to maturity. And be promptly wiped out by the virus nobody thought to retain resistance to 700 years ago. Or by reproductive freedom fighters.

[Nosforontu]

Originally Posted by RyanW

A eugenics program backed up by real science (and with more practical goals than the mostly racist ones of the early 20th century) could modify the human species more quickly than the conventional natural selection method of shooting DNA at anything that survives to maturity.

Especially if you are starting with a small selected population to begin with and then genetically screen them and remove potential colonist with genetic taboo traits that you don't want in your colony. A colony that founded by people who want to create an artists utopia might screen out people who are deaf or who are color blind. They might also only allow among the initial colonist people who have in gurps terms acute senses as they want to create a colony where people "can appreciate the nuances of the art".

Originally Posted by RyanW

And be promptly wiped out by the virus nobody thought to retain resistance to 700 years ago. Or by reproductive freedom fighters.

To be honest I suspect that without easy FTL or frequent travel between colonies that this is going to be a major concern for them all compared to Earth. Smaller initial populations and even if they are not purposely trying to genetically screen/breed on that colony they are going to have much smaller over all gene pool compared to earth considering that only x number of people traveled to that colony and started it. Add in the fact that they are not likely to have brought every Terran animal/disease with them...

They will probably be healthier overall than a regular Terran due to less disease exposure, but have lower levels of disease resistance overall as fewer of them each generation are continuously exposed to new Earth diseases/Pandemics without regular contact.

[Ji ji]

Higher radiation level could lead to wider genetical modification on short evolutional times.

First idea on possible modifications: adaptation to different gravity. I think of free-fall adapted species.

Color. Living on worlds with different irradiation can lead to alternative defensive pigmentation.

Sight. Our sight is centerd on the main radiation of Sun star. Different stars have different peak radiation, that is different "white" wave lenght.

Reproduction. Overpopulation can lead to genetically enginereed societies, where there's a reproductive elite (queens) alongside sterile masses. (Bee or ant society).

[CraigM]

Originally Posted by Nosforontu

If your initial colonist were selected from Olympic Level Athletes, and the environment of the colony really requires very athletic/fit people to survive then your colony is probably going to have a fairly high preponderance of people with various Athletic Talents. They will probably also have a higher Health Attribute/Dex/ or Strength scores as well. Just because the initial genetic starting pool might exclusively be composed of the top 1% of people in athletics in the world.

You could of course set the criteria differently and get different results as long as your starting population is not generic humans but humans selected from the greater population because they all share trait x or lack traits y. As a bit more crude example if your colony is composed elusively of Asians then none of them are going to be blondes or red heads barring extreme environmental factors on the colony world.

This is quite likely to have unpleasant and/or unexpected consequences.

Example 1: Bio scientists have been selectively breeding lab rats for over a hundred years now. The breeders try to pick the healthiest animals, and tend to use rate of mass gain during infancy as a proxy for health. As a result, the most common strains of lab rats now used grow to adult size much more rapidly than wild rats, but also tend to have much shorter potential lifespans (if given time; in reality, most wild rats become prey or starve before they grow old, and most laboratory rats are eventually euthanased). The candle that burns twice as bright, etc.

Example 2: There is an island off the coast of the U.S. (Martha's Vineyard), that was isolated from the mainland for a long time, and was settled by a group from a single English village. By chance, this village had a higher than usual rate of hereditary deafness. By the time they built a bridge to the mainland, something like 20% of the population were deaf. As a result, deafness had become something akin to colour-blindness in the severity of its impact. As everyone had deaf relatives, absolutely everyone on the island was fluent in sign language, so Deafness had lost most of its isolating and disabling effect.

[Johnny1A.2]

Originally Posted by CraigM

This is quite likely to have unpleasant and/or unexpected consequences.

Example 1: Bio scientists have been selectively breeding lab rats for over a hundred years now. The breeders try to pick the healthiest animals, and tend to use rate of mass gain during infancy as a proxy for health. As a result, the most common strains of lab rats now used grow to adult size much more rapidly than wild rats, but also tend to have much shorter potential lifespans (if given time; in reality, most wild rats become prey or starve before they grow old, and most laboratory rats are eventually euthanased). The candle that burns twice as bright, etc.

Example 2: There is an island off the coast of the U.S. (Martha's Vineyard), that was isolated from the mainland for a long time, and was settled by a group from a single English village. By chance, this village had a higher than usual rate of hereditary deafness. By the time they built a bridge to the mainland, something like 20% of the population were deaf. As a result, deafness had become something akin to colour-blindness in the severity of its impact. As everyone had deaf relatives, absolutely everyone on the island was fluent in sign language, so Deafness had lost most of its isolating and disabling effect.

This^^.

The thing is that genetics doesn't work in the simplistic Hollywood way, there isn't (usually) a single 'gene for 'x' to be selected for or against'. Instead there's a gene that causes trait 'x' under certain conditions, while also producing trait 'y' under other overlapping but different conditions, while at the same time influencing the manifestation of traits linked to other genes, all modified by circumstances. Add in epigenetic factors, and probably other things we don't even know about yet, and the complexity becomes daunting.

Treating traits in isolation, and breeding for or against them without consideration of side-effects, rarely works well if done over more than a few generations. The 'random mating' approach does have the advantage that it forces trait combinations to stay within certain viable ranges over generations, though it does so in a nasty way.

Matters are made worse, for a scientific eugenics program, by the fact that humans breed slowly, compared to most mammals. It takes over a decade for most humans to reach breeding age, and longer before s/he is at a really healthy, good age for reproduction. Even if you don't mind using teenagers as your breeders (and time constraints would argue for just that in a long-term program, saw 5 or 6 years off each generation in the program and you cut half a millennium off a 100 generation project), you still are limited to probably no more than six generations a century or so.

Contrast that to cats or rabbits, and the issue becomes clear.

[Nosforontu]

Originally Posted by CraigM

This is quite likely to have unpleasant and/or unexpected consequences.

Almost certainly but we are likely to be talking about extreme levels of isolation between human colonies if we assume limited/hard/slow FTL between colonies (which seems like a good assumption in the campaign past if we are talking about space evolution). I am sure that a colony whose total initial population was say 5,000 humans for the next 5-20 generations is going to have issues going forward no matter how careful the initial choices were.

Originally Posted by CraigM

Example 2: There is an island off the coast of the U.S. (Martha's Vineyard), that was isolated from the mainland for a long time, and was settled by a group from a single English village. By chance, this village had a higher than usual rate of hereditary deafness. By the time they built a bridge to the mainland, something like 20% of the population were deaf. As a result, deafness had become something akin to colour-blindness in the severity of its impact. As everyone had deaf relatives, absolutely everyone on the island was fluent in sign language, so Deafness had lost most of its isolating and disabling effect.

Yep you are going to run into problems with a small isolated population which is both common in the real world and useful in gurps to give you a points to afford the good stuff for your template ;). Of course it is not always a bad thing per say the island of Icaria for various reasons has the worlds largest percentage of people who live to 90+ living there.

The point being of course you and others are certainly right to say that their will be problems, but for the purposes of a game I would also be inclined to let their be bonuses as well for the isolation probably in the form of various planet talent groups to reflect careful selection from the founders and the colonies inhabited environment.

[dcarson]

You will also have non genetic changes. A colony on a 2+ gravity world will not have changed much genetically in a couple generation but the people will be noticeably different in appearance from growing up under that. If they emigrate to a 1 gravity world the kids will be normal.