Domestication Flashcards
How is domestication multi-faceted?
It has a cultural process and a biological process.
How does biological domestication work?
A form of genetic selection
The parent animal (first one domesticated) becomes isolated from the wild population.
This results in genetic drift from wild ancestors.
What two kinds of genetic drift from wild ancestors can there be in biological domestication?
Active or passive!
Describe active genetic drift in biological domestication.
Active: Humans select for things to change them biologically and genetically in a specific way.
Describe passive genetic drift in biological domestication?
Things may just move in the proper direction to cause it naturally. May be completely random.
Describe the cultural aspect of domestication.
Changes in how the animal becomes included in the social structures of human societies.
What role does the animal play in its interaction with humans.
What animal is a good example of a lot of cultural domestication with little biological domestication?
Horses! What we use horses for has changed a lot time, but they have not changed much at all biologically.
What kind of relationship is domestication?
A symbiotic relationship.
Domestication is more of a _____. _____ over _____
Process! Change over time.
Define symbiosis.
All conditions of permanent living together of two different species.
True or false: symbosis is positive for both parties.
False! It can be, but generally one gains more or less from the relationship.
What are symbiotic relationships also called?
Guest/host interactions
In a symbiotic relationship, who is the guest?
The subordinate partner.
In a symbiotic relationship, who is the host?
The dominant partner.
True or false? The guest and host roles relate to who benefits the most.
No! Doesn’t mean that either gains more or less from the relationship. It just basically means which does more work or has more interaction.
What is perfect symbiosis? Some qualities of it?
Occurs when both partners derive equal benefits.
Without domination by one of the partners.
Both are equal and there is no subordinate or dominant partner.
This is very very rare. Some argue that it doesn’t even exist.
What are the two categories of symbosis?
Host initiated and guest initiated.
Describe host initiated symbiotic relationships.
The dominate partner initiates the relationship.
What are the three host-initiated symbiotic relationships in order of most mutual to least.
Feeding, Taming, Domestication.
Describe guest-initiated symbiotic relationships.
The subordinate partner initiates the relationship.
What are the three guest-initiated symbiotic relationships in order of most mutual to least.
Scavenging, robbing, social parasitism.
Where does domestication fall on the domestication scale?
Host initiated. HEAVILY skewed to the hosts’ benefit.
What is the common misconception of domestication?
That humans and animals get an equal benefit. Not true! humans/the host, gets a lot more out of the partnership.
What is the difference between taming and domestication?
In domestication, they are much more integrated into our life. We interact with them on a near daily basis.
What is the domestication hypothesis?
The belief that the primary factor selected for during domestication was a behavioral trait named “tamability”
Who came up with the domestication hypothesis?
Dmitry Belyaev.
Define the idea of tamablitiy:
Animals have a different genetic disposition to interacting with other animals, including humans.
Explain how Belyaev ended up researching domestication.
He fell out of favor with the Cesar. Disguising it as a good thing, they sent Belyaev off to Siberia and gave him a lab.
Before Belyaev’s experiment, what were some misconceptions about domestication? Around what time was this?
Around 1950.
Thought that domestication was an active process that humans did. We captured animals and raised them away from their wild ancestors. We believe that it was all on the humans side.
We also believed that domestication was 100% environmental. We didn’t know that we could select genes for behaviors.
What does Dr. Flowers think about experiments?
That sometimes the best research is done simply. Without much technology or equipment.
Reflected in Belyaev’s experiment.
What did Belyaev believe about tamability?
-It was an innate behavioral trait that all animals possessed
-Within any population of animals there was variation in its expression.
-In other words, some animals had more genetic predispositions towards being friendly. And because there is variation, we can select for it.
What did he believe about the genetics of tamability?
That they could be selected for (like we select for coat color)
Tamability is controlled by “higher order genes” (genes that control other traits.)
-Basically, if one selected for tamability, then other phenotypic changes would occur.
-He also believed that their were certain specific phenotypic traits associated with domestication.
What traits did Belyaev think were connected with tamability?
Blazed forehead
Curled tail
Floppy ears.
Piebald Coat (White splochy color coat.)
What was Belyaev’s experiment?
He tested wild silver foxes for tamability and sorted them into categories.
Then, we allowed them to breed within these groups.
After twenty generations, he observed many of the phenotypic changes that he predicted.
What were the domestication categories that Belyaev sorted his foxes into?
Class III: Least domesticated. Flee from experimenters or bite when stroked or handled.
Class II: Allow being handled or petted, but show no emotionally friendly response.
Class I: Friendly towards experimenters, wagging their tails or whining.
Class IE: the “Domesticated elite” Eager to establish human contact. Whimper to get attention. Lick or sniff experimenters.
In this experiment what was the selected group? The unselected group?
Selected: The tame group.
Unselected: the wild (Class III)
What phenotypic changes did Belyaev observed after his experiment.
Dwarf and giant breeds.
Piebald coat color
Blazed forehead
Floppy ears
Curled tails
Wavy or curly hair.
Why did these results prove Belyaev’s idea of higher order genes?
All that we was selecting for was whether they tried to bite or wanted attention.
ALL of these major changes came from selecting for the friendliness.
What four physiological changes were also produced?
-Breeding seasons. Foxes become less seasonal with domestication.
-Fertility. Foxes became more fertile with domestication.
-Hearing age. It takes longer for the young to be able to hear as they become more domesticated.
-Sight age. It takes longer for the young to be able to see as they become more domesticated.
What kind study was this?
A prospective study! It establishes cause and effect.
What did this study prove?
That increasing genetic frequency of domestication changes phenotypes. This proves that tamability is a higher order gene.
Domestication is a ___ not an ____. Its _____.
Process. Event. Ongoing.
True or false. There is never really a domesticated animal.
True! its an ongoing process. We are domesticating. The animals are changing continuously.
Why can some species change faster than others?
Reproduction rates. Rats have young faster, have more generations, and can change faster, than a species like horses.
retrospectively, if Belyaev was right, what else should be right?
The longer an animal has been domesticated, the more phenotypic variations there would be.
A direct positive relationship.
