ANTH - Chpt. 7 - The Global Distribution of Dogs and Week 7/8 Readings

What system was historically used to categorize dog breeds, which is still retained by modern kennel clubs?

Classification according to the job or function they performed

How many modern populations of dogs are referred to as "breeds"?

Approximately 400 populations

What is a "purebred" dog defined as?

A population of closely related animals of similar appearance maintained from a known foundation stock through genetic isolation and deliberate selection

How were early dog "breeds" created by humans prior to modern goal-directed breeding?

Through selection by people that was primarily unconscious rather than goal-directed, with little effort to prevent mating with available dogs

How extensive is the morphological size variation seen across modern dog breeds?

Size varies across two orders of magnitude, with morphological differences reminiscent of different species from different phylogenetic families

What does the archaeological record reveal about ancient proto-dog genetics from sites over 30,000 years ago?

Proto-dogs died out and do not align with or contribute to modern dog genetics

Where are the archaeological sites located that contained remains of 30,000+ year-old proto-dogs?

Belgium and Siberia

What modern dog breed group is characterized as being energetic, social, and highly trainable to retrieve game from land or water?

The Sporting Group

Which dog breed group is known for its endurance, independence, and strong prey drive when tracking prey?

The Hound Group

Which group consists of large, powerful dogs originally used for guarding, pulling, and protection?

The Working Group

What is the primary function of dogs in the Terrier Group?

To hunt vermin

Which group of dogs is described as small, affectionate, portable, and well-suited to indoor living?

The Toy Group

What characterises the Non-Sporting Group in kennel clubs?

A diverse collection of breeds varying widely in size, coat, and temperament that do not fit neatly into other categories

What specialized behaviors characterize the Herding Group?

Herding and protecting livestock (and children)

What is the purpose of the Canine Behavioral Assessment and Research Questionnaire (C-BARQ)?

To investigate normal and abnormal behaviors and classify behavioral phenotypes in dog populations

Who was Balto?

The famous 1925 historic sled dog who transported diphtheria antitoxin to Nome, Alaska

Where is Balto's taxidermied body preserved today?

At the Cleveland Museum of Natural History

What type of tissue was used to sequence Balto's high-coverage ancient DNA genome?

A 5 mm × 5 mm piece of his underbelly skin tissue

How coverage-dense was the nuclear genome sequenced from Balto's tissue sample?

40.4-fold coverage

Did Balto belong to the official American Kennel Club (AKC) Siberian husky breed?

No, he belonged to a working population managed by Leonard Seppala prior to the AKC breed establishment in 1930

Was Balto able to leave behind any direct descendants?

No, because he was neutered at 6 months old

What were the two predominant ancestral lineages found in Balto's genome?

Arctic lineage (68%) and Asian lineage (24%)

What percentage of Balto's ancestry in a supervised genetic analysis came specifically from the working Alaskan sled dog population?

34%

Did Balto's genome carry any discernible wolf ancestry?

No, he carried no discernible wolf ancestry

How did Balto's genetic diversity and inbreeding metrics compare to modern breed dogs?

He had higher genetic diversity (shorter runs of homozygosity) and significantly lower inbreeding metrics

Why did Greenland sled dogs exhibit higher inbreeding scores under allele frequency approaches despite being working dogs?

Due to long-term geographic isolation in Greenland

Why do working sled dog populations carry fewer potentially damaging genetic variants than modern breed dogs?

Selection for physical performance and fitness purges deleterious genetic load better than selection for modern aesthetic breed standards

What dataset of phylogenetically constrained scores was used to evaluate rare damaging variants in Balto's genome?

The Zoonomia 240-mammal alignment

What was Balto's predicted shoulder height based on random forest modeling of size-associated SNPs?

Approximately 55 cm tall

What were the predicted physical traits of Balto's coat and color based on his genome?

A double-layered, predominantly black coat with a melanistic mask and minimal white markings on the chest and legs

Did Balto carry the genetic variants for single-layer coats, "wolf agouti", or "Northern domino" patterns?

No, he carried no single-layer derived alleles and was homozygous for tan points masked by black features

Which two starch-processing genes were evaluated in Balto to study his dietary adaptations?

MGAM and AMY2B

How did Balto's starch digestion capacity compare to wolves and modern domestic dogs?

His starch digestion was enhanced relative to wolves and Greenland sled dogs (via the dog-adapted MGAM version), but reduced compared to modern domestic dogs

How enriched were Balto's homozygous missense variants in tissue development genes compared to normal expectations?

3.02-fold enrichment (ranking 4th out of nearly 900,000 tested gene-set pairs)

What body systems were influenced by Balto's unique enrichment of missense variants in tissue development genes?

Skeletal and joint formation, body weight, coordination, and skin thickness development