Hello everyone:
I just wanted to know how are genes passed down through the generations? How do breeders breed for temperament?

Thanks!

Does anyone know how the "mind" is inherited?

I don't think so. All we know is that it is ---
that's why you know your lab will fetch, your collie will chase cars, and your border collie will likely be smart.

Surely it's all in the DNA, in the genes, one copy from the sire, one from the dam. But how the personality is formed from the DNA, I don't think that it well understood.

I'm not sure how dog breeders do it specifically, but here are two really interesting websites to look into:

Study of the Molecular Basis of Tame and Aggressive Behavior in the Silver Fox Model
http://cbsu.tc.cornell.edu/ccgr/behaviour/History.htm

Nice Rats, Nasty Rats: Maybe It’s All in the Genes
http://www.nytimes.com/2006/07/25/health/25rats.html?ex=1311480000&en=ee8f5fbaf0576814&ei=5090&partner=rssuserland&emc=rss&_r=0

Brains are body tissue just like leg bones, hearts, or hair. How they manifest is up to the DNA they inherit from their parents. A brain that is genetically encoded to show an aptitude or basic personality type is what it is. Environment can build upon what's there in the DNA. But it can't overcome it.

But it's still an odds game. Two tall parents are likely to have tall children, but they might have a child of normal height.

A breeder can breed two dogs that both have a temperament for X--with the hope of getting a litter of X types. But some may not have it.

The skill is identifying the X puppies over many generations, thereby concentrating that particular set of genes. After enough generations, the likelihood of getting predominantly X puppies increases.

It's how breeds are created. Breed enough dogs that look and behave like poodles, (selecting the most poodle-like as the breed stock in each generation) and eventually you'll get nothing but poodles.

In horses we have a saying " you breed the best to the best, and hope for the best"
Imo, breeding and genetics will only take you so far, mother nature does have a sense of humor. A lot of temperment is preprogrammed in the young, but a portion is also learned. If you have a youngster that has an overly aggressive mother chances are the longer that youngster is with the mother it will pick up those traits.
Again imo, best practice is meet the sire and dam, check out their personalities, then when you decide on a youngster socialize the heck out of it. There is a school of thought that anything a pup learns before twelve weeks old will stay with it for the rest of its life, so socializing and teaching people are good early on are a great foundation. Again jmho.

I'm a HUGE believer in the period of 7-12 weeks for early behavior imprinting but starting with great genetics is primary.
As stated above you breed "the best to the best". What's best for one is often different from what's best to another and the term "temperament" can mean many different things to different people.
The temperament I like could probably drive most folks up a wall.
"Temperament", lack of attention/poor training are why the pounds are full of dogs.

IMHO, genetics are the potential. Through training & life experiences, we are able to shape behavior. But without a good temperament based in genetics, you will always be limited.

An example of comparison...

My Vigo is a fearful dog. He came home at 12 weeks old and has been training ever since. He is now 3.5 years old. His fear, while somewhat shaped by his experiences, is absolutely genetically based. That's easy enough to know when you know other dogs from his same lines (sire's side) that exhibit similar behaviors. Even with training & positive experiences, he is and will always be a fearful dog. He can mask it & hide it, because I've taught him how to do that, but deep down...it's still there.

On the other hand, my friend breeds dogs. She sent a wee little puppy out into the world. That same pup came back at about 9 months old, nearly dead. She was extremely ill due to an untreated blockage...and luckily recovered after weeks and thousands of dollars of treatment. This pup was under socialized and had no training, aside from some really bad behaviors she had picked up (barking endlessly in a crate, fearful/nervous behaviors, etc.). After only a few months of training, following her recovery, she was a well-trained, well-adjusted pup.

So why can't I get Vigo to be like that? Certainly, my skills as a trainer play a role...my friend is indeed a better trainer than I am. But the bottom line is that her pup has nice solid genetics and her potential is greater than my dog's...his genetic temperament tells him to be afraid, to flee.

I have heard/read that "shyness", I mean TRUE shyness, is an inherited gene in people as well as dogs.

Growing up(3000+++ years ago ) I had a friend like that. They were always pushing her to come out. Don't know if that was the right way or if it worked. But I really felt sorry for her.

I have seen some Shepherds like that. Very sad, VERY hard to change.

I've only started with adult dogs. Kenzi was abandoned as a 4 m/o then shuffled around to 3 different homes/fosters by the time I got her at 9 m/o. She's a soft dog, but super stable with a "go anywhere" type of temperament.

There's got to be some solid genetic component in there because pretty much everything was done wrong in her formative weeks and months.

Interesting, I was extremely shy only one in my family.