It must be my age. How do you interbreed two species and not have a hybrid result?
If they mean that the hybrids didn't take over from both groups how do they know? Usually hybrids die early or exist along side one or both groups or supercede them.
I keep asking this question, not only here but from what ever expert that will spare the time to talk, untill you obtain the DNA from a 'pure HSS' and a 'pure HSN' how can you tell if we are hybrids or not?
If the 'club' had a better record of open mindedness and common sense I would listen more attentivly.
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And once again I raise the point that experts I've spoken to duck! How doyou tell if an animal is a hybrid from its DNA unless you have DNA samples from the parent species?
DNA samples from 'pure' HSN and 'pure' HSS are as rare as dinosaur bites! As DB says, to much surmise from too small samples in my opinion.
DNA samples from 'pure' HSN and 'pure' HSS are as rare as dinosaur bites! As DB says, to much surmise from too small samples in my opinion.
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt
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Minimalist
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How do you interbreed two species and not have a hybrid result?
I always thought that this was the fairly basic definition of a "species."
Thus, if they can interbreed, why would they be different species in the first place?A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
(As long as we're asking impertinent questions I figured I may as well join in with you, Dig.)
Something is wrong here. War, disease, death, destruction, hunger, filth, poverty, torture, crime, corruption, and the Ice Capades. Something is definitely wrong. This is not good work. If this is the best God can do, I am not impressed.
-- George Carlin
-- George Carlin
We do indeed KB. It is generally assumed that Mules are sterile, they are not! Their fertility is low so it remains easier to produce Mules by continued cross breeding.
But as I have asked before, if we bred Mule to Mule and horses and donkeys died out would somebody in the future be able to say that the Mule was a hybrid?
I think not, but I am open to correction and education on this.
But as I have asked before, if we bred Mule to Mule and horses and donkeys died out would somebody in the future be able to say that the Mule was a hybrid?
I think not, but I am open to correction and education on this.
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt
Hybrids
Digit, nobody knows either way since there are too many variables with too little data. Genetic drift says it's unlikely. However, there was a lot of traveling and intermingling going on in paleo times. Whether HN provided anything to the HSS gene pool will be figured out after the Neanderthal Genome becomes more complete, but it won't be easy to determine. You can bet your oversized eyebrows that Svante Paabo will be searching for the big brain D allele first. How he'll do it is beyond me.... untill you obtain the DNA from a 'pure HSS' and a 'pure HSN' how can you tell if we are hybrids or not?
Natural selection favors the paranoid
We also have the problem, which I have mentioned several times, that there is no "moment of conception", but rather a period of time during which the ovum wall remains permeable. Sometimes, more than one sperm gets in.
If both are XX or XY, no biggie, nobody notices. But if not, then the progeny is XXY, which is what hermaphrodite DNA looks like. AND, to complicate life even further, now that we know that sperm vary, some slow and long lived, some fast, but die soon, some not all that functional, but only there to deliver the enzymes to make the ovum wall permeable... not all the sperm that get in to fertilize an egg have to be from the same donor.
Think about that a minute. You can have more than one "father". The idea blows huge holes in the whole idea of male descent. Now, when we look at DNA we see all these "haplotypes", some of which are associated with particular regions where they are more common. But nobody has the same set that you can trace back to any given point.
I have the report on just 20 of my Haplotypes. If you just iterate 2 to the twentieth, you get more men than have ever existed. DNA shows that 20% of the Y chromosome lines dont come from where the birth records say. I dont think anyone here is surprised to find out women sometimes cheat.
But when they do, and sperm are there from two more more men, then you get a whole new set of haplotypes in the Y chromosome line that is handed down. This is never going to be sorted out. There is no Y chromosome line that remains intact all the way back to ancient times, much less the paleolithic or hybridization with Neanderthals.
But because the ladies were screwing Neanderthals, some of their haplotypes- for white skin, bushy beards, shorter digits, blue or green eyes, etc, are still with us.
If both are XX or XY, no biggie, nobody notices. But if not, then the progeny is XXY, which is what hermaphrodite DNA looks like. AND, to complicate life even further, now that we know that sperm vary, some slow and long lived, some fast, but die soon, some not all that functional, but only there to deliver the enzymes to make the ovum wall permeable... not all the sperm that get in to fertilize an egg have to be from the same donor.
Think about that a minute. You can have more than one "father". The idea blows huge holes in the whole idea of male descent. Now, when we look at DNA we see all these "haplotypes", some of which are associated with particular regions where they are more common. But nobody has the same set that you can trace back to any given point.
I have the report on just 20 of my Haplotypes. If you just iterate 2 to the twentieth, you get more men than have ever existed. DNA shows that 20% of the Y chromosome lines dont come from where the birth records say. I dont think anyone here is surprised to find out women sometimes cheat.
But when they do, and sperm are there from two more more men, then you get a whole new set of haplotypes in the Y chromosome line that is handed down. This is never going to be sorted out. There is no Y chromosome line that remains intact all the way back to ancient times, much less the paleolithic or hybridization with Neanderthals.
But because the ladies were screwing Neanderthals, some of their haplotypes- for white skin, bushy beards, shorter digits, blue or green eyes, etc, are still with us.
Any god watching me hasta be bored, and needs to get a life.
The use of the word hybrid implies that HN and HS were separate and distinct species. John Hawks points out that it takes between 2 and 10 million years of separation to evolve into different species.
The differences between HN and HS were merely somewhat more pronounced than the regional differences we see today. There should have been no difficulty in fertilization.
Because of some differences in blood type there would sometimes be complications in utero. We have the same problem today with a syndrome called erythroblastosis fetalis, or "blue baby". Infants are not lost today, but at one time the condition was usually fatal to the infant.
This condition only occurs with subsequent pregnancies - after having at least one child. So HN/HS reproduction was no problem. An admixture yes - hybrid no.
The differences between HN and HS were merely somewhat more pronounced than the regional differences we see today. There should have been no difficulty in fertilization.
Because of some differences in blood type there would sometimes be complications in utero. We have the same problem today with a syndrome called erythroblastosis fetalis, or "blue baby". Infants are not lost today, but at one time the condition was usually fatal to the infant.
This condition only occurs with subsequent pregnancies - after having at least one child. So HN/HS reproduction was no problem. An admixture yes - hybrid no.
I've never seen that figure before Beags and if it's correct, and I can see no reason as to why he might be wrong, why all the panic in the British press about the impending extiction of the Polar Bear and the Emperor penguin I wonder?John Hawks points out that it takes between 2 and 10 million years of separation to evolve into different species.
If Hawkes is correct, both species pre-date the present ice by a sizable margin.
Perhaps A. Bore doesn't know it all yet, I wonder if he'll give the Nobel money back if he's proved wrong?
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt
Hi Digit. I'll try to find the Hawks quote.
The Polar bear is just a cold adapted brown bear. A really good analogy in the HN/HS discussion. Brown bears are moving north in the warmer weather and mating with polar bears. Lots of sightings of mixed gene bears.
During the next glacial period, the polar bear features will quickly reassert themselves. But you're right, they will be said to be extinct.
The Polar bear is just a cold adapted brown bear. A really good analogy in the HN/HS discussion. Brown bears are moving north in the warmer weather and mating with polar bears. Lots of sightings of mixed gene bears.
During the next glacial period, the polar bear features will quickly reassert themselves. But you're right, they will be said to be extinct.
I couldn't find that quote, but I'll keep looking. The search engine on Hawks website really sucks.
What he was saying was that it took 2-10 million years in mammals, for a group to differentiate enough to cause reproduction to fail or to have sterile hybrids as a result.
I may email him if I don't find it soon.
Hawks et al have just released a study on the acceleration of evolution. He has a lot of comments on it and I'll get them posted soon.
What he was saying was that it took 2-10 million years in mammals, for a group to differentiate enough to cause reproduction to fail or to have sterile hybrids as a result.
I may email him if I don't find it soon.
Hawks et al have just released a study on the acceleration of evolution. He has a lot of comments on it and I'll get them posted soon.
http://johnhawks.net/weblog/reviews/nea ... _2006.html
It's a Hawks paper on "introgression".
Whew, I'm glad I'm done looking.
Digit - I finally found this quote!. It only took me a week.But I thought that "species" means "no interbreeding!"
Get with the times, man! Mammal species just don't establish reproductive barriers very quickly. Comparing mammals, postzygotic isolating mechanisms take between 2 and 10 million years to evolve. No primate species pairs have evolved postzygotic isolation on the timescale represented by the evolution of Homo. When archaic and modern humans were in contact, they certainly interbred.
It's a Hawks paper on "introgression".
Whew, I'm glad I'm done looking.
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fossiltrader
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Simple Failing.
Thie we come across all the time simple to understand i think?
just because it looks human means nothing we have to avoid humanising everything we see it not impossible a human looking creature could be simply put an animal with no sense of right or wrong morals etc truth is we really dont know.
just because it looks human means nothing we have to avoid humanising everything we see it not impossible a human looking creature could be simply put an animal with no sense of right or wrong morals etc truth is we really dont know.