pitabread
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- Jan 29, 2017
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Agreed, individual genotypes making up particular gene pools, or Kinds.
"Kinds" is not a defined term relevant to biology. Consequently I don't recognize it as relevant for classification of individual gene pools.
Why do you need a citation?
You claimed that "Because the genome once had all racial characteristics within, and through selective breeding our genetic variability has been reduced."
Do you have support from any genetic studies that the genome "once had all racial characteristics within". Because I can tell you right now that based on my prior readings of genetics literature with respect to human genes, the distribution of 'racial characteristics' is a result of various alleles as a result of mutations throughout the human genome. Or to put it another way, you can't cram all the variability associated with every phenotype into a single genome.
But if you believe otherwise, then by all means provide a citation to back this up.
You just admitted you agreed that selective breeding reduced the genetic variation.
I was speaking with respect to selective breeding of dogs, not people. In the case of humans, populations have been increasing substantially and gene flow is abundant. You won't find many cases these days of genetic isolation in human populations.
I don’t know about you, but I can easily discern the difference between Asian and African, and the overlap between the two Afro-Asian.
Sure, it's easy to line up a couple distinct human phenotypes and play a game of "spot the difference". But that's not what I'm talking about. I'm talking about drawing a hard line in the sand with respect to different populations. If you try to do so, you're going to quickly find there is too much overlap both with respect to physical traits and underlying genetics to truly divide populations into distinct categories.
No it’s not and never has been observed. Oh, you mean by those labels you admit are arbitrary and want to give up until those arbitrary labels arbitrarily support your arbitrary claims?
I think you are misconstruing what I mean by labels being arbitrary. What I mean by that is that they are in effect artificial classifications used to make identification of particular biological groups of organisms easier. But the classifications themselves have no true biological reality. A zebrafish doesn't come with Danio rerio stamped on its underbelly. This is simply a species classification we have assigned to this particular type of fish.
At any rate, per the biological species concept (i.e. the formation of distinct breeding populations via allopatric or sympatric speciation), speciation has been observed. There is no denying that as it's been directly observed.
This from the man that argued a change in phenotype meant nothing?
When have I ever suggested that a change in phenotype meant "nothing"?
Mastiff have black and brown hair too. No one argues a mutation might change hair color, length of nose (or beak or snout) but that is quite different than changing some missing common ancestor into an ape and a human?
Is it really though? I mean, you fully accept that mutations can change physical traits, so it such a stretch to accept that an accumulation of changes to physical traits would result in something that you ultimately classify differently?
Or is this a case of not being able to view evolution as a recursive process which builds on what comes before it?
I have never disagreed. I simply contend you have no basis to claim mutations can bring about a new species, when it can’t even change a Husky into anything else.
But again, with something like Huskies you're dealing with a situation whereby artificial selective pressures are being used to shape a particular breed to produce that particular breed.
That said there is absolutely no reason a person could not continually breed Huskies selecting for different traits until the resultant offspring were physically distinct from traditional Huskies. This is after all what dog breeders did with early domesticated dogs in the first place.
Can you give an example where this has not happened?
Where reducing a population size didn't reduce genetic variability? I'm not sure why you asking that question. If you want examples of increasing genetic variability, then increasing population size is the way to go, not reducing it.
But doesn’t that require that allele to start from just two, and on just to their descendants? So to be fixed in the population, it would have to come from say, an original pair?
A novel allele needs to only come from a single individual. If that individual mates with other organisms and produces resultant offspring with that allele, then that allele can spread through the population via continued reproduction.
Or are you suggesting if I randomly acquire a mutation, entire populations will then randomly acquire the same random mutation? Sorry, those odds are illogical.
No, mutations spread through a population as it is passed to offspring via reproduction.
Agreed, which must occur in at least one of a pair and to its descendants. To be fixed in the population, the population must come from that original pair.
Again, it only needs to occur in a singular organism and be successfully passed down via reproduction. An organism can have multiple sexual partners. A male with a particular mutation could impregnate multiple females or vise-versa a female with a mutation could have offspring by way of more than one male.
Agree and disagree. I agree Husky mating with Mastiff produce the Chinook. I’ve yet to observe a mutation change the Husky, Mastiff or Chinook into another breed. Yes, I know you believe it can, but isn’t it belief or faith you have a problem with?
You accept that wolves were domesticated and evolved into individual dog breeds. Breeding a population of Huskies into something sufficiently physically distinct would be the exact same process.
You appear to be simultaneously accepting and rejecting evolution. It's odd.
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