The 20 Principles of Genes, Environment and Breeding

Golden Retriever Mother and Puppies

Hereditary traits are inherited equally from both parents. However, the mother will have more influence in the puppies’ behavior than the father because she spends more time with them.

Genes code for the traits an organism will show, physical as well as behavioral, but genes are not all. The environment of that organism also plays a crucial role in the way some of its genes will express themselves.

Genes play a large role in the appearance and behavior of organisms. Phenotypes (the appearance of the organism) are determined, in various degrees, by the genotype program (the sum of all genes) and the interaction of the organism with the environment. Some traits are more modifiable by environmental factors, others less. For example, while eye color is solely determined by the genetic coding, genes determine how tall an individual may grow, but nutritional, as well as other health factors experienced by that organism, determine the outcome. In short: the environment by itself cannot create a trait and only a few traits are solely the product of a strict gene coding.

The same applies to behavior. Behavior is the result of the genetic coding and the effects of the environment on a particular organism. Learning is an adaptation to the environment. Behavioral genetics studies the role of genetics in animal (including human) behavior. Behavioral genetics is an interdisciplinary field, with contributions from biologygeneticsethologypsychology, and statistics. The same basic genetic principles that apply to any phenotype apply also to behavior, but it is more difficult to identify particular genes with particular behaviors than with physical traits. The most reliable assessment of an individual’s genetic contribution to behavior is through the study of twins and half-siblings.

In small populations, like breeds with a limited number of individuals, the genetic contribution tends to be magnified because there is not enough variation. Therefore, it is very important that breeders pay special importance to lineages, keep impeccable records, test the individuals, and choose carefully, which mating system they will use. Failure to be strict may result in highly undesirable results in a few generations with the average population showing undesired traits, physical as well as behavioral.

We breed animals for many different purposes. Breeding means combining 50% of the genes of one animal (a male) to 50% of the genes of another animal (a female) and see what happens. We can never choose single genes as we wish and combine them so we get the perfect animal, but knowing which traits are dominant, which are recessive, and being able to read pedigrees helps us.

Siberian Husky Puppies

Litter mates share on average 50% common genes, but only on average. Each litter mate got at random 50% of its genes from the male (father) and 50% from the female (mother), but not necessarily the same 50% from each (Photo by

Here are some guidelines for breeding (inspired by ‘20 Principles of Breeding Better Dogs’ by Raymond H. Oppenheimer). The objective of the following 20 principles is to help breeders strive for a healthy and fit animal in all aspects, physically as well as behaviorally.

1. The animals you select for breeding today will have an impact on the future population (unless you do not use any of their offspring to continue breeding).

2. Chose carefully the two animals you want to breed. If you only have a limited number of animals at your disposition, you will have to wait for another generation to make any improvement. As a rule of thumb, you should expect the progeny to be better than the parents.

3. Statistical predictions may not hold true in a small number of animals (as in one litter of puppies). Statistical predictions show accuracy when applied to large populations.

4. A pedigree is a tool to help you learn the desirable and undesirable attributes that an animal is likely to exhibit or reproduce.

5. If you have a well-defined purpose for your breeding program, which you should, you will want to enhance specific attributes, but don’t forget that an animal is a whole. To emphasize one or two features of the animal, you may compromise the soundness and function of the whole organism.

6. Even though, in general, large litters indicate good health and breeding conditions, quantity does not mean quality. Quality is produced by careful study, patience to wait until the right breeding stock is available, evaluating what you have already produced, and above all, having a breeding plan that is at least three generations ahead of the breeding you do today.

7. Skeletal defects are the most difficult to change.

8. Don’t bother with a good animal that cannot reproduce well. The fittest are those who survive and are able to pass their survival genes to the next generation.

9. Once you have approximately the animal you want, use out-crosses sparingly. For each desirable characteristic you acquire, you will get many undesirable traits that you will have to eliminate in succeeding generations.

Adult wolves regurgitate food for the puppies to eat. Many dog mothers do the same (Photo by Humans For Wolves).

10. Inbreeding is the fastest method to achieve desirable characteristics. It brings forward hidden traits that may be undesirable and you want to eliminate. However, repeated inbreeding can increase the chances of offspring being affected by recessive or deleterious traits.

11. Once you have achieved the characteristics you want, line-breeding with sporadic outcrossing seems to be the most prudent approach.

12. Breeding does not create anything new unless you run into favorable mutations (seldom). What you get is what was there to begin with. It may have been hidden for many generations, but it was there.

13. Litter mates share on average 50% common genes, but only on average. Each litter mate got at random 50% of its genes from the male (father) and 50% from the female (mother), but not necessarily the same 50% from each.

14. Hereditary traits are inherited equally from both parents. Do not expect to solve all of your problems in one generation.

15. If the worst animal in your last litter is no better than the worst animal in your first litter, you are not making progress.

16. If the best animal in your last litter is no better than the best animal in your first litter, you are not making progress.

17. Do not choose a breeding animal by either the best or the worst that it has produced. Evaluate the total breeding value of an animal by means of averages of as many offspring as possible.

18. Keep in mind that quality is a combination of soundness and function. It is not merely the lack of undesirable traits, but also the presence of desirable traits. It is the whole animal that counts.

19. Be objective. Don’t allow personal feelings to influence your choice of breeding stock.

20. Be realistic, but strive for excellence. Always try to get the best you can. Be careful: when we breed animals for special characteristics, physical as well as behavioral, we are playing with fire, changing the genome that natural selection created and tested throughout centuries.

As always, have a great day!



The Thai Rikki-Tikki-Tavi


Rikki-Tikki-Tavi, the mongoose hero from Kipling’s “The Jungle Book.”

We all know Rikki-Tikki-Tavi, the brave mongoose from Kipling’s ‘The Jungle book.’ This is the story of Mah Noy, the brave dog from Koh Lanta Yai in Southern Thai.

Koh Lanta Yai (เกาะลันตา) remains one of  Thailand‘s well-kept secrets (I shouldn’t even reveal the name). It is relatively close to the better-known islands of Koh Phuket and Koh Phi Phi, but is practically inaccessible, requiring two flights, a long drive, and two ferry trips. Tourists are few and far between on this particular South Andaman island and it is virtually devoid of Western influence, except for a few resorts for those who want a taste of unspoiled paradise. Koh Lanta Yai is the biggest of 52 islands of which only 12 are inhabited.

Of course, it’s much easier for me to get to Koh Lanta, as I am resident on a neighboring island only 43.5 nautical miles away. The beaches of Koh Lanta are idyllic: the sand unsullied the water clear and warm (about 86-88º F) and the underwater world along the coral reef just breathtaking (although not literally, I’m happy to say). I always look forward to my diving assignments nearby, drifting above the Staghorn and the Anemone corals monitoring the various species’ fortunes. What a great job!

Thai Fisherman With Dog

Thai fisherman like to have their dogs with them for company and practical purposes.

When I’m working in Koh Lanta, I always go ashore in the evening and stay in modest accommodation right on the beach. On one of these occasions, just before sunset, I was sitting in front of my bungalow, cleaning my equipment, when two children came along to talk to me, as always, curious about foreigners.

I had seen them both before; they belong to the food booth where I often eat, just behind the bungalow. We talked about the sea and the fish and about my diving gear, which of course fascinates them.

After having washed my gear, I decided to walk the 30 yards up the cliff to grab something to eat, and the kids followed me. My Thai is not as good as I would like, but my inadequacies have their advantages. As it is so difficult to pronounce words correctly, I nearly always commit embarrassing mistakes that produce a great deal of giggling—and giggling is the best way I know to decrease distance between strangers.

Woman with her dog: Thai street food booth

Thai street food cooking and selling is a small family business and since dogs are part of the daily life in Thailand it is not unusual to see them with their owners at work.

“Khun cheu aria?” (What’s your name?), I asked the little boy who was giggling the most and who happened to have one of his front teeth missing.

He told me his name, which sounded funny to me. Thais have all sorts of interesting nicknames, and they are especially fond of animal names. Elephant, shrimp, crab, fish, bird, duck, rabbit, turtle, and even chicken are common names—but I’ve never heard a nickname like this little boy’s. It was then that his mother, Poo (Crab), the owner of the food booth, told me the story.

Five years earlier, two days after giving birth to the now gap-toothed boy, Poo was cooking dinner whilst the family dog catnapped behind the cradle where her newborn baby was happily babbling away to himself.

Thais usually cook outdoors. It’s always warm and they don’t like the smell of food indoors. The dog was typically Thai, of unknown origin, the size of a small spaniel, with an unruly black and white coat, and friendly, deep brown eyes. They had found him on the street a couple of years beforehand and had fed him. For want of a better name, they called him just (หมาน้อย), Mah Noy. He stayed around and finally moved in a couple of weeks later after conquering their hearts. The pressure of natural selection for dogs in Thailand is on kindness. The kindest dogs have a greater chance of survival and pass on their ‘kinder’ genes to their progeny.

On that particular day, Mah Noy gave Poo such a fright she almost lost hold of her hot pan, which could have resulted in serious burns. The dog had suddenly emitted a deep growl and then in two agile, determined jumps, just missing the baby’s cradle, he launched himself on top of a cobra, biting it firmly behind the head.

Thai boy and puppy

Mah Noy (หมาน้อย), the boy, got his unusual name for a good reason.

The Andaman Cobra (Naja sagittifera) is an impressive snake, measuring about three to four feet in length. The effects of its venom are devastating; it is capable of killing a human in 30 minutes.

Poo was terrified, rushed to pick up the baby, and ran out of the front gate into the street where she began shouting for her husband. Na (short for Chai Cha Na = victory) came running to the scene and charged into the backyard to grab a spade. The cobra was lying a few feet from the dog, apparently lifeless, but, just in case, Na cut it in two with a well-aimed strike with the spade. Mah Noy looked up at him, gasping for air, and barely able to wag the tip of his bushy tail. Na understood right away that the dog was dying, picked him up and, holding his dog firmly on his lap with one hand, he rode his motorbike as quickly as he could to the local vet.

On the way to the vet, Mah Noy peed and pooped on his lap. Na stopped to get a better grasp on the dog. Mah Noy looked at him, gasped for air for a last time and gave a final wag of his tail. Na understood it was too late for the vet and the strong fisherman from the South Andaman Sea began to weep like a child, right there on the side of the road to Klong Dao, in the fading light of the day on which he had come so close to losing his first-born baby boy.

When Na got home to Poo and their newborn, they buried Mah Noy in their backyard and placed a yellow marigold on top of the grave (yellow is the color of friendship for Thais). That evening, they decided to call their baby boy หมาน้อย, Mah Noy, which in Thai means ‘puppy.’

Sawasdee khrap,

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