genetic defect probabilties?

[aj]

Got to wondering about genetic defects. Dwarfism occured in three different breeds in the 1900's. Lets take th. If the Angus breed lasts another 3,000 years what are the chances that th would occur in that breed......through an new mutation? What about the same thing for say dwarfism in the Shorthorn breed over the next 3,000 years. How often do these mutations occur? 100 years? 1,000 years? 10,000 years? What about the old dwarfism defect in say the Angus? Could this still be floating around in pedigrees? Do they know markers for dwarfism? Just wondering out loud....Do we really know because man hasn't really domesticated livestock that long.

 

[librarian]

My, very imperfect, understanding is that the kind of mutations you are pondering replicate because they hitch hike on human intervention . Not to say they are intentional actors, more like a coevolution of dysfunctional genes and dysfunctional selection.
Will this change during the next 3000 years? I think we'll be lucky if the livestock industry as we know it lasts another 30 years. The day is coming when there will be very little genetic diversity in cattle, defective or otherwise. Livestock will be genetically designed for maximum profit to the meat packing industry. The cattle business has always mutated under this system in a crude, lurching, romantic way. With precise artificial selection the days of sitting by the stove planning matings will be as remote as cattle drives thru open prairie.

 

[knabe]

Defects don't hitch hike because of humans..

Google this. "how do genetic mutations occur"

That's why there will always be defects no matter how people try to demonized humans.

At some level, who cares about diversity in cattle, currently, there is very little diversity in human thought.

 

[CAB]

  Human Thought? What?

 

[aj]

Are you kidding me KnaBe. There is more diversity of thought today in the USA than anytime in the history of the world.

 

[librarian]

I'm not sure I agree with you aj.
I recommend a movie called Exit Thru the Gift Shop.

Along with mass produced culture, we communicate with a mass produced reductionist language now.
We have razed the unwritten words from modes of existence that depended upon a fine reading of the environmental nuances particular to survival.
Now its #subtle.

Visually, I think we see more shades of green than any other color.
I wonder if that will shift to blue.

 

[librarian]

knabe, I probably understand the science in crayon colors, but the concept of humans as enablers of flipping the fitness script seems to have some validity.

From wiki
"Genetic hitchhiking
Genetic hitchhiking, also called genetic draft or the hitchhiking effect,[1] is when an allele changes frequency not because it its is under natural selection, but because it is near another gene on the same chromosome that is undergoing a selective sweep. When one gene goes through a selective sweep, any other nearby polymorphisms that are in linkage disequilibrium will tend to change their allele frequencies too.[2] Selective sweeps happen when newly appeared and hence rare mutations are advantageous, and increase in frequency. Neutral or even slightly deleterious alleles that happen to be close by on the chromosome 'hitchhike' along with the sweep. In contrast, effects on a neutral locus due to linkage disequilibrium with newly appeared deleterious mutations are called background selection. Both genetic hitchhiking and background selection are stochastic (random) evolutionary forces, like genetic drift.[3]"

 

[shortybreeder]

That's all fine and dandy, librarian, but what the original question asks is what's the chance of a new mutation coming about within a population. The creation of a mutation has nothing to do with human selection because it is the creation of a new allele within a population, not a change in frequency of the allele.

 

[knabe]

Are you kidding me KnaBe. There is more diversity of thought today in the USA than anytime in the history of the world.

not really. we are taught what to think, not how to think.  you've got to be kidding.
at least there is still diversity with using defects right? 

 

[librarian]

That's all fine and dandy, librarian, but what the original question asks is what's the chance of a new mutation coming about within a population. The creation of a mutation has nothing to do with human selection because it is the creation of a new allele within a population, not a change in frequency of the allele.

You're right. I was just thinking about how a mutation would rapidly spread in a population.
I think mutations happen all the time , most just dont get traction.
Anyway, I was coming at it from this philosophical point of view...how to think, not what to think.  Not trying to grind an axe, sorry if it sounded that way.
Just getting the info from Wikipedia is ironic.

" Supporters of the concept regard memes as cultural analogues to genes in that they self-replicate, mutate, and respond to selective pressures.[3]

The word meme is a shortening (modeled on gene) of mimeme (from Ancient Greek μίμημα pronounced [míːmɛːma] mīmēma, "imitated thing", from μιμεῖσθαι mimeisthai, "to imitate", from μῖμος mimos, "mime")[4] coined by British evolutionary biologist Richard Dawkins in The Selfish Gene (1976)[1][5] as a concept for discussion of evolutionary principles in explaining the spread of ideas and cultural phenomena. Examples of memes given in the book included melodies, catchphrases, fashion, and the technology of building arches.[6]

Proponents theorize that memes are a viral phenomenon that may evolve by natural selection in a manner analogous to that of biological evolution. Memes do this through the processes of variation, mutation, competition, and inheritance, each of which influences a meme's reproductive success. Memes spread through the behavior that they generate in their hosts. Memes that propagate less prolifically may become extinct, while others may survive, spread, and (for better or for worse) mutate. Memes that replicate most effectively enjoy more success, and some may replicate effectively even when they prove to be detrimental to the welfare of their hosts.[7]"

https://en.m.wikipedia.org/wiki/Meme

 

[librarian]

So the meme (dwarfy cattle make money) would hitchhike on the defect to replicate itself.
Just a thought experiment, indicating I should go outside and replicate the vanishing get to work meme.

 

[aj]

knabe.....no one tells anybody how to think. Have you ever been on facebook? Everybody has a chance to speak their opinion. Its called social media. There are capitalists, socialists, communists, Republicans, Libertarians, Democrats,KKK, Black lives matter,Libertarians, left wingers, right wingers, rednecks, hippies, people who hate new country music, people who hate old country music, there are more opportunities to debate, argue and state ones opinion than ever before. No one forces anyone how to think. If you don't control the media.....thats what happens.

 

[aj]

I would think that sometime.......some where......there would be discussions about how a breed association might be proactive in monitoring genetic defects. In the Herford breed St. Louis Lad, who was born in 1898 started spreading the genetic defect of dwarfism around the country. It wasn't untill the 1950's that dwarfs began to show up in numbers. IF breeds know where to look.........if thet know what markers to look for........and say they have blood drawn on say the grand champ bull of the Herford breed........could they check his marker for th.....just as a precaution? What about marble bone? Could you check a Shorthorn for the marble bone? Would the markers be the same as markers from say a Red Angus? Could you even have a computer run samples of bloodwork? Seems like there might be tools out there for this.

 

[BroncoFan]

I think some mutations are just random and just occur. Others might be cause by our selecting for certain traits. At anytime another mutation could come along. Crossovers between alleles happen. So do deletions, duplications, etc. Some obvious mutations have been good for cattle I.E. Polled Herefords and Red Angus. Others like PH and TH are not when not managed correctly. My $0.02.

 

[aj]

I think its interesting that the Shorthorn, Angus, and Herfords were all developed in roughly the same area in the old world.......and they all three showed dwarfism at one time after they came across the pond.

 

[knabe]

How do you know it didn't show up before. 

 

[aj]

That was kind of my point. If the Angus, Herford, and Shorthorn all had common ancestors.......were they similar enough to where certain mutations occured as opposed to say Limousin,Simmental, Gelbvieh and what not. Has these "exotic" breeds ever had a dwarfism problem?