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HoneyBadgerDC
08-16-2014, 12:01 PM
Suppose you had an unlimited amount of time, this work would be passed on from generation to generation. You were charged with the task of taking a dog from the breed status to a new species status. What strategy would be used to accomplish this?

OldGuy
08-16-2014, 12:38 PM
Can you only use standard breeding techniques or can I hire biologist who can insert genes or delete genes directly. It would be much faster, I'm sure, if I could do the latter,

septimus
08-16-2014, 12:51 PM
Loosely related to OP's question: Peter and Rosemary Grant recently observed a new variety of finch emerge in just a few decades (http://press.princeton.edu/titles/10282.html).



I think [the Grants' work is] fantastic, the most exciting research finding Iíve read in the last decade.

HoneyBadgerDC
08-16-2014, 12:55 PM
Can you only use standard breeding techniques or can I hire biologist who can insert genes or delete genes directly. It would be much faster, I'm sure, if I could do the latter,

Breeding methods, or setting up situations where only the right type might survive.

Stranger On A Train
08-16-2014, 01:04 PM
There are already breeds of dogs that could not conceivable mate with other breeds, so in a sense this has already happened (although the genetic material is still compatible). Since dog breeding is a very artificial form of selection we don't tend to regard this as speciation but it would be viewed so if it occurred in nature.

The most certain way to identify speciation on the microbiological level is to add or split chromosomes. Even some species with a slight difference in chromosome count may still be able to breed between each other but will almost never breed "true" (e.g. have a full complement of chromosomal pairs in meiosis and are generally sterile (e.g. mules). Chromosomal splits are generally due to mutation or replicative errors in epigenic factors and thus occur in a fairly random distribution. Other deletion, modification, or insertion of enough alleles to prevent interbreeding is a long term stochastic process of gene shifting, mutation, and lateral transfer of genetic material from retroviruses. How long that takes to cause speciation depends upon the degree of nucleotide sequence and pheneotypical differences.

Stranger

AK84
08-17-2014, 04:16 AM
What about with suitable isolated humans? Australian Aboridginals and Pacific Islander have shown no problem in mating with other humans, despite tens of thousands of years of isolation. Most sub-Saharan Africans are extremely genetically different from the rest of mankind, and each other.

Smeghead
08-17-2014, 06:39 AM
There are already breeds of dogs that could not conceivable mate with other breeds, so in a sense this has already happened (although the genetic material is still compatible). Since dog breeding is a very artificial form of selection we don't tend to regard this as speciation but it would be viewed so if it occurred in nature.

Dogs are a ring species. Even though the largest and smallest dogs can't directly interbreed, you can get gene flow between them via a series of intermediates. Thus they are correctly considered the same species, and would be so considered even if they had arisen in the wild.

The most certain way to identify speciation on the microbiological level is to add or split chromosomes. Even some species with a slight difference in chromosome count may still be able to breed between each other but will almost never breed "true" (e.g. have a full complement of chromosomal pairs in meiosis and are generally sterile (e.g. mules).

I would quibble with this a bit. Changes in chromosome number alone isn't a very big deal, as long as all of the genetic information is present and not rearranged in order to any great extent. As long as every chunk of DNA has a homologous partner to pair up with, it doesn't really matter how many chunks there are.

njtt
08-17-2014, 07:11 AM
Loosely related to OP's question: Peter and Rosemary Grant recently observed a new variety of finch emerge in just a few decades (http://press.princeton.edu/titles/10282.html).

Yes, but that is in the Galapagos. What else would you expect! :D

Mangetout
08-17-2014, 04:12 PM
Dogs are a ring species. Even though the largest and smallest dogs can't directly interbreed, you can get gene flow between them via a series of intermediates. Thus they are correctly considered the same species, and would be so considered even if they had arisen in the wild.

Hang on a moment... I don't think that's how ring species are classified when we discover them in the wild - for example, Larus gulls (http://en.wikipedia.org/wiki/Ring_species#Larus_gulls) - a ring comprising 6 species.

Smeghead
08-17-2014, 06:20 PM
Rings don't necessarily have to be geographic, though that's the most obvious and easy to understand situation. In this case (dogs), we're talking about subpopulations that are separated by size rather than geography, but the end result is the same: two populations at the extremes that cannot interbreed, but with intermediates providing gene flow.

Mangetout
08-17-2014, 06:50 PM
Rings don't necessarily have to be geographic, though that's the most obvious and easy to understand situation. In this case (dogs), we're talking about subpopulations that are separated by size rather than geography, but the end result is the same: two populations at the extremes that cannot interbreed, but with intermediates providing gene flow.

Agreed - point is, that the ring can be considered to be composed of multiple species.

Some Call Me... Tim
08-19-2014, 12:52 AM
Kill all the dogs except for Great Danes and Chihuahuas.

The remaining dogs are now two different species.

MrDibble
08-19-2014, 07:31 AM
Suppose you had an unlimited amount of time, this work would be passed on from generation to generation. You were charged with the task of taking a dog from the breed status to a new species status. What strategy would be used to accomplish this?
Do I also have an unlimited amount of funding? Because my strategy would be to deposit a bunch of them - selecting generally robust, "working dog" types - on one isolated, largish island (or an archipelago) with plenty of prey (something the size of Cyprus or Sardinia would do) and keep the island isolated for long enough for speciation to occur. 1 million years should do it.

I call this the Snoopy strategy. It should be obvious why.

iiandyiiii
08-19-2014, 09:29 AM
What about with suitable isolated humans? Australian Aboridginals and Pacific Islander have shown no problem in mating with other humans, despite tens of thousands of years of isolation. Most sub-Saharan Africans are extremely genetically different from the rest of mankind, and each other.

Your use of "extremely" is a relative term -- as far as most species on earth, including more closely related species like Chimpanzees, humans are not particularly genetically diverse. Chimps have three times the genetic diversity of humans, IIRC.

This is probably because very few groups of humans have been truly isolated for long periods of time, while two groups of chimpanzees (for example) might have been separated by a river or mountain range for hundreds of thousands of years.

HoneyBadgerDC
08-19-2014, 02:06 PM
Here is what I was kind of thinking. Lets say the goal was to create a species from canines that
if left in the wild would be so successful that they would quickly deplete thier hunting supply and starve ending the species. Not unrealistic as species do have to devolve as well as evolve to adapt to food suppllies.

The next step would be to identify the characteristics that you would be most be concerned with regardless of if you want them in or out of your breeding program. We might allow 150 years to develop a breed that best represented the species we were trying to create.

Now we spend another 150 years stretching the limits of this breeds ability to survive under a gradually changing artificially created enviroment. Ruthless culling and using technology as it develops to identify the genetic structure and tracking it. If we identified realistic methods in nature of introducing new genes even though they would be highly unlikely we could use whatever tecniques we needed to use to introduce new genetic material as long as it could have happened naturally.

Could some kind of plan or strategy be employed over a long term to create new species in much shorter time periods?

cochrane
08-19-2014, 02:17 PM
Do I also have an unlimited amount of funding? Because my strategy would be to deposit a bunch of them - selecting generally robust, "working dog" types - on one isolated, largish island (or an archipelago) with plenty of prey (something the size of Cyprus or Sardinia would do) and keep the island isolated for long enough for speciation to occur. 1 million years should do it.

I call this the Snoopy strategy. It should be obvious why.

You'd have a new species of beagle? :confused: