Speciation

ldwechsler wrote:Note that Thandi, a particularly variated individual, had no problems coupling with Victor.

Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.

Naturally becoming a separate species would be hard to do in a reasonable time frame, if you have a reasonably large population.

Unnaturally creating a new species could be as easy as pasting a couple chromosomes together and rearranging some of the DNA. You wouldn't even need to make new genes!

Actually, I would think the biggest area for potential "speciation" would be creating two mutually incompatible gene mods. Even if both lines can interbreed with classic humans, they might not be able to interbreed with each other.

quite possibly a cat wrote:Naturally becoming a separate species would be hard to do in a reasonable time frame, if you have a reasonably large population.

Unnaturally creating a new species could be as easy as pasting a couple chromosomes together and rearranging some of the DNA. You wouldn't even need to make new genes!

Actually, I would think the biggest area for potential "speciation" would be creating two mutually incompatible gene mods. Even if both lines can interbreed with classic humans, they might not be able to interbreed with each other.

From what we've seen here on earth, speciation is difficult. Lots of breeds of horses, dogs, etc., and they breed. To not breed, you would need either some sort of genetic "instruction" or a real change in genetic form.

I think Eric pushed things a bit. Note also that there seems not be be a problem with people on San Martin breeding (never mentioned anywhere in text) and they've been under extreme gravity. Honor is a Meyerdahl B and she has been able to breed with Hamish who is not.

ldwechsler wrote:Note that Thandi, a particularly variated individual, had no problems coupling with Victor.

Weird Harold wrote:Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.

I have just been made aware of blood type incompatibility, which is one possible cause of sterility. So something like that could easily stop procreation, without affecting coupling.

tlb wrote:

ldwechsler wrote:Note that Thandi, a particularly variated individual, had no problems coupling with Victor.

Weird Harold wrote:Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.

I have just been made aware of blood type incompatibility, which is one possible cause of sterility. So something like that could easily stop procreation, without affecting coupling.

Major changes usually take more than a couple of generations. Go back far enough and we're all pretty much related. I read somewhere that everyone with roots in Western Europe is likely descended from Charlemagne.

But a couple of generations in and you have a fairly small sample. It takes time to spread.

ldwechsler wrote:

tlb wrote:[ uote="ldwechsler"]Note that Thandi, a particularly variated individual, had no problems coupling with Victor.

Weird Harold wrote:Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.

I have just been made aware of blood type incompatibility, which is one possible cause of sterility. So something like that could easily stop procreation, without affecting coupling.

Major changes usually take more than a couple of generations. Go back far enough and we're all pretty much related. I read somewhere that everyone with roots in Western Europe is likely descended from Charlemagne.

But a couple of generations in and you have a fairly small sample. It takes time to spread.[/quote]

According to geneticist 1 in 8 people in China and central Asia are related to Genghis Khan

saber964 wrote:

ldwechsler wrote:Note that Thandi, a particularly variated individual, had no problems coupling with Victor.

Weird Harold wrote:Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.

I have just been made aware of blood type incompatibility, which is one possible cause of sterility. So something like that could easily stop procreation, without affecting coupling.

Major changes usually take more than a couple of generations. Go back far enough and we're all pretty much related. I read somewhere that everyone with roots in Western Europe is likely descended from Charlemagne.

But a couple of generations in and you have a fairly small sample. It takes time to spread.[/quote]

According to geneticist 1 in 8 people in China and central Asia are related to Genghis Khan[/quote]

Keep in mind that related to is not the same as descended from...the common ancestor might be generations earlier.

The point is that it takes quite a few generations to really get a major genetic change to be common, at least for humans.

And not being able to breed requires real change. Lions and tigers breed and I think tigons can actually continued to breed...are not sterile. There are major genetic problems, however, but they are sometimes overcome.

I doubt the differences between those from Ndebele and other planets would be that great.

Given that as we figure out more and more of the human genome and realize how much comes from other hominid lines such as neanderthal and densovians it is pretty clear even some levels of speciation is not enough of a hurdle to block horney people from finding a way.

The drift would have to be pretty massive to really be a hurdle to interbreeding and with modern technology and enough desire I don't see even a few millennia of drift being sufficient.

That said some amount of speciation is bound to happen when you scatter a species across a wide number of biomes and environments if you go a long enough period of time. God knows in our own past there were a fairly robust amount of hominid species many of which coexisted or at least lived at the same general time period.

ldwechsler wrote:

quite possibly a cat wrote:Naturally becoming a separate species would be hard to do in a reasonable time frame, if you have a reasonably large population.

Unnaturally creating a new species could be as easy as pasting a couple chromosomes together and rearranging some of the DNA. You wouldn't even need to make new genes!

Actually, I would think the biggest area for potential "speciation" would be creating two mutually incompatible gene mods. Even if both lines can interbreed with classic humans, they might not be able to interbreed with each other.

From what we've seen here on earth, speciation is difficult. Lots of breeds of horses, dogs, etc., and they breed. To not breed, you would need either some sort of genetic "instruction" or a real change in genetic form.

I think Eric pushed things a bit. Note also that there seems not be be a problem with people on San Martin breeding (never mentioned anywhere in text) and they've been under extreme gravity. Honor is a Meyerdahl B and she has been able to breed with Hamish who is not.

Breeding animals is relatively "natural". Natural changes take a long time for specialization.

However if you are making arbitrary changes with gene altering technologies you can get a different species really easily. So one genetic "problem" that people can have is chromosomes with some of the DNA sections reversed. The person who has the section of DNA flipped around can be totally fine. An inversion. You can also swap chunks of DNA around in a balanced translocation. There are a couple ways this can cause problems. First, it might break a gene or regulatory component, but that's not all that common. The second area where it can cause problems is during gamete production. If the change is in only one of chromosomes (heterogeneous) of a pair you might have unbalanced chromosomes after gamete production in the gametes! That means lowered fertility, or even infertility.

However a genetic engineer could do that a bunch of times to both chromosomes (homogeneous) and make sure not to break anything! Then the person wouldn't have any problems and their gametes would be fine! However, if they had a child with an unaltered human, that child would have a whole crapton of heterogeneous chromosomes. They'd be infertile.

BAM! Technically you have a new species, if you go by the interbreeding definition. But outwardly? Exactly like a regular human.

The point is, if you want to deliberately create a new species, you can. In Honorverse it seems like they try to make sure mods actually result in someone who is human.

That said: I'm not sure how the Mfecanes could be a couple generations away from being a new species. A couple of generations shouldn't make much of a change. It might be the character who said it was just wrong and doesn't understand what they're talking about!

quite possibly a cat wrote:

quite possibly a cat wrote:Naturally becoming a separate species would be hard to do in a reasonable time frame, if you have a reasonably large population.

Unnaturally creating a new species could be as easy as pasting a couple chromosomes together and rearranging some of the DNA. You wouldn't even need to make new genes!

Actually, I would think the biggest area for potential "speciation" would be creating two mutually incompatible gene mods. Even if both lines can interbreed with classic humans, they might not be able to interbreed with each other.

Breeding animals is relatively "natural". Natural changes take a long time for specialization.

However if you are making arbitrary changes with gene altering technologies you can get a different species really easily. So one genetic "problem" that people can have is chromosomes with some of the DNA sections reversed. The person who has the section of DNA flipped around can be totally fine. An inversion. You can also swap chunks of DNA around in a balanced translocation. There are a couple ways this can cause problems. First, it might break a gene or regulatory component, but that's not all that common. The second area where it can cause problems is during gamete production. If the change is in only one of chromosomes (heterogeneous) of a pair you might have unbalanced chromosomes after gamete production in the gametes! That means lowered fertility, or even infertility.

However a genetic engineer could do that a bunch of times to both chromosomes (homogeneous) and make sure not to break anything! Then the person wouldn't have any problems and their gametes would be fine! However, if they had a child with an unaltered human, that child would have a whole crapton of heterogeneous chromosomes. They'd be infertile.

BAM! Technically you have a new species, if you go by the interbreeding definition. But outwardly? Exactly like a regular human.

The point is, if you want to deliberately create a new species, you can. In Honorverse it seems like they try to make sure mods actually result in someone who is human.

That said: I'm not sure how the Mfecanes could be a couple generations away from being a new species. A couple of generations shouldn't make much of a change. It might be the character who said it was just wrong and doesn't understand what they're talking about!

It doesn't look like there were all that many genetic changes deliberately put in.

Frankly, I think Eric pushed things a bit. It probably would have taken more than a few generations for a separate species to be created.

Another thought: Have the Scrags been able to mate with non-modified humans? That would be a similar kind of thing but I don't think it has been mentioned. We know they can have sex but nothing has been mentioned about kids.