Animal Domestication
Dr. Carlos A. Driscoll
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Animal Domestication
Dr. Carlos A. Driscoll
WWF Chair in Conservation Genetics,
Wildlife Institute of India, Dehradun
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Simple questions
• Evolutionary context of domestication
– Where did it take place?
– When did this happen?
– Who domesticated animals?
– Why did they do it?
– What is domestication?
– How did it come about?
•Neo-Darwinian domestication
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Selection by natural means, “the survival of the fittest”
was not just plausible or possible, but probable
Animal Domestication
Dr. Carlos A. Driscoll
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Animal Domestication
Dr. Carlos A. Driscoll
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World population since 10,000 BC
Animal Domestication
Dr. Carlos A. Driscoll
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Animal domestication events
DonkeyCow, pig
Turkey,
duck
Llama, alpaca,
guinea pig
Goat, sheep,
cow, pig
Pig, chicken,
water buffalo
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• Sedentism
• Social complexity and stability
– Band: a small, highly mobile egalitarian society based on hunting and gathering and characterized by a lack
of formal governmental institution and economic specialization. Political dominance is gained through achieved
leadership rather than ascribed leadership; as many leadership positions exist as circumstances call
for and there are qualified persons to fill them
– Tribal society: is an egalitarian society larger and more complex than a band and often sedentary, that practices
either hunting and gathering or food production and has politically autonomous communities. Political dominance
is gained through achieved leadership rather than ascribed leadership, and sodalities are important in integrating
the social system
– Civilization: a complex sociopolitical form defined by the institutions of the state and the existence of a distinctive
“great tradition” (sets of elite values and behaviors that emerge from folk traditions and that are expressed
in distinctive rituals, art, writing, or other symbolic forms)
– State: a stratified society that has developed the institutions for effectively upholding an order of stratification.
States are strongly territorial, with complex, well-defined political leadership, hierarchies of settlement,
and often elaborate and highly specialized bureaucracies
• Accessibility to useful wild plants and animals
• Complex before others
The domesticating society
(Council of Biology Editors, 1994)
12 Terminal Pleistocene, more than 12,000 years ago
Barley
Einkorn
Emmer wheat
Pea
Chick pea
Lentil
Flax
Bitter Vech
Wild einkorn Wheat
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Animal Domestication
Dr. Carlos A. Driscoll
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Cow
Goat
Sheep
Pig
Barley
Einkorn
Emmer wheat
Pea
Chick pea
Lentil
Flax
Bitter Vech
Fig
Olive
�Horse
Camel
�
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Animal Domestication
Dr. Carlos A. Driscoll
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Goats
11,000
10,500
10,000
11,000
9,500 – 9,000 BP
10 - 11,000
Wild barley
Wild einkorn Wheat
Wild emmer
wheatFig
Olive
• Raising one’s own food required farmers
to stay in one place year round, forever
− Accumulation of goods
− Division of labor
− Stable platform for an intensification of selection
Cattle
Sheep
Pigs
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Six criteria were first outlined in Francis Galton’s 1865 paper
‘The First Steps Towards the Domestication of Animals’
1) They should be hardy
2) They should have an inborn liking for man
3) They should breed freely
4) They should be found useful to the savages
5) They should be comfort loving
6) They should be easy to tend
‘Good’ domesticates - 1865
Animal Domestication
Dr. Carlos A. Driscoll
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1) Flexible diet (Hardiness)
2) Good disposition (Inborn liking of Man)
3) Breed in captivity (Breed freely)
4) Comparatively fast growth rate (Useful)
5) Fair temperament, no panicking (Comfort loving)
6) Modifiable social hierarchy (Easy to tend)
‘Good’ domesticates – today (1)
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1) Flexible diet (Hardiness)
2) Good disposition (Inborn liking of Man)
3) Breed in captivity (Breed freely)
4) Comparatively fast growth rate (Useful)
5) Fair temperament, no panicking (Comfort loving)
6) Modifiable social hierarchy (Easy to tend)
7) Commensal initiative
‘Good’ domesticates – today (2)
Animal Domestication
Dr. Carlos A. Driscoll
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1) Flexible diet (Hardiness)
2) Good disposition (Inborn liking of Man)
3) Breed in captivity (Breed freely)
4) Comparatively fast growth rate (Useful)
5) Fair temperament, no panicking (Comfort loving)
6) Modifiable social hierarchy (Easy to tend)
7) Commensal initiative
‘Good’ domesticates – today (3)
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• Natural selection
– Process by which favorable heritable traits become more common
in successive generations of reproducing organisms, and unfavorable traits
become less common, due to differential reproduction of genotypes
• Sexual selection
– Intraspecific competition driven by the "struggle between the individuals
of one sex, generally the males, for the possession of the other sex”
• Artificial selection
– Selective breeding
Evolution today
Animal Domestication
Dr. Carlos A. Driscoll
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•Natural selection
– Sexual selection
• Artificial selection
– Methodical
– Unconscious
Darwin’s view
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• Artificial selection
– Methodical
� Intentional progress towards
a preconceived ideal
– Unconscious
� Unintentional changes
resulting from management
or interaction
Darwin’s view (2)
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• Artificial selection
– Methodical
– Unconscious
– Weak
� Post-zygotic,
as in natural selection
– Strong
� Pre-zygotic
Animal Domestication
Dr. Carlos A. Driscoll
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Darwin’s view (3)
• Artificial selection
− Methodical
− Unconscious
− Only humans
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“Mr. Wallace … argues that man,
after he had partially acquired those
intellectual and moral faculties which
distinguish him from the lower animals,
would have been but little liable to bodily
modifications through natural selection
or any other means. For man is enabled
through his mental faculties “to keep
with an unchanged body in harmony with
the changing universe.” He has great
power of adapting his habits to new
conditions of life. He invents weapons,
tools, and various stratagems to procure
food and to defend himself. When he
migrates into a colder climate he uses
clothes, builds sheds, and makes fires;
and by the aid of fire cooks food
otherwise indigestible”
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Pathways to animal domestication
• Commensalism – natural selection
• Traditional barnyard – unconscious/methodological
(artificial selection)
•Modern agribusiness – methodical
• Exploited captives – little to no selection
e.g. domestication of wolves
Animal Domestication
Dr. Carlos A. Driscoll
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In genetic terms:
• The ongoing process of domestication is a form of evolution
• This process of changing population allele frequencies
over generations is applied to modifying organisms
such that they more readily accept human contact and control
• Domestication happens to populations, not to individuals
What is domestication? (1)
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What is domestication? (2)
• Not an either/or game. Differs by species
• Phenotypic commonalities among domesticates include:
Dwarfs and giants
Piebald coat color
Reproductive cycle changes
Wavy or curly hair
Rolled tails
Shorter tails, fewer vertebrae
Floppy ears
Living with people/lack of fear
• Physiology, morphology and behavior
are an interconnected suite of traits
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• Lack of fear of people
A heritable predisposition to tameness
What is domestication? (3)
Animal Domestication
Dr. Carlos A. Driscoll
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• Lack of fear of people
A heritable predisposition to tameness
What is domestication? (4)
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What is domestication? (5)
• Lack of fear of people
– A heritable predisposition to tameness
• Phenotype = genotype + environment
– Like other effects, domestication (phenotype) is influenced by genes
(genotype) and environment, and their interaction
• Like language
– Genes predispose us to learn language,
but nothing says we have to learn language
– Developmental window for learning language best
– Environment determines what language we speak
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Innate
fear
Group
status
Fear
of exposure
Social ordering?
Generalized
fear/vigilance
Self
image
Fear
of disease
Domestication represents a suite of behaviors
What is domestication? (6)
…and a suite of genes
Animal Domestication
Dr. Carlos A. Driscoll
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• Lack of fear of people through individual taming
• A cultural process
Culture is the transmission of behaviors or ideas
from one individual to another through learning
• Domestication did not come about through the individual
taming of captured animals or from the learned acquisition
of a ‘culture of domestication’
• It came about as a consequence of differential survival
and reproduction in a population
What is domestication NOT?
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• 130 founders from farm population
– 30 males, 100 vixens
• The standard test includes five steps:
1) Observer approaching fox cage
2) Observer stays near closed cage
3) Observer is near open cage but does not initiate tactile contact
4) Tactile contact
5) Observer stays near closed cage
• Selection only for tameness; 5% males, 20% females
• Restricted human contact
Belyaev and Trut initiate Fox-Farm experiment in 1959
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• Dramatic changes after 8 - 10 generations, almost 20% of foxes
were ‘tame’ and sought out human contact; By 20 generations
up to 35%
• Coat color changes
• Floppy ears
• Curled tails
• Estrus cycle change
•Mating behavior
• Highly social
Results of fox farm experiment
Animal Domestication
Dr. Carlos A. Driscoll
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• Domestication is in fact heritable
•Morphological traits recapitulated by selection on behavior
• Genetic variation present in ‘wild’ population prior
to any selection for domestication
• A master set of 10 to 20 genes? Obviously pleiotropic
Some implications of the fox farm experiment
Animal Domestication
Dr. Carlos A. Driscoll
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A digression on domestication
• If the animals in Africa are just as appropriate to domesticate…
•Why don’t we find widespread domestication
of African animals?
•Why did sedentism first arise in the Near East?
Historical efforts to domesticate new species failed
because they didn’t start from a wide enough genetic base,
and didn’t pursue selection efforts appropriately
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Destabilizing selection
• “Selection for tame behavior seems to result in breaking up
previously integrated ontogenic systems and thus lead
to multiple phenotypic effects that seem genetically unrelated
to the selected character, namely tame behavior”
• “Destabilizing selection could break up normal patterns
of gene activation and inhibition and result in a great increase
in the range and rate of hereditary variation,
which again is subject to specific selective forces”
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Evolvability
• Capacity of a system to evolve
• Depends on amount of variation open to selection
• Type of variation
• Tied to physiology
Animal Domestication
Dr. Carlos A. Driscoll
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BSC
• Species: groups of actually or potentially interbreeding populations
that are reproductively isolated from other such groups
– Most species occupy distinct ecological niches
which is the keystone of evolution
• Subspecies: a geographically defined aggregate of local populations
which differ taxonomically from other subdivisions of the species.
Subspecies are reproductively compatible
– Evidence should include concordant distribution of multiple,
independent, genetically based traits. Members should share
a unique geographic range or habitat, a group of phylogentically
concordant phenotype characters, and a unique natural history
Mayr, 1940; O’Brien and Mayr, 1991
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Behavioral genetics
Seeks to understand the roles of genetics and the environment
in forming individual behavioral variation
• It is difficult to define the behavior in question
• It is difficult to measure the behavior
• Heritability is influenced by environment
(ecophenotypic variability)
• Behaviors are complex traits involving multiple genes
– Pleiotropic, epistatic
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References and further reading
• Salamini, F., H. Ozkan, et al. (2002). "Genetics and geography of wild cereal domestication
in the near east." Nat Rev Genet 3(6): 429-441
• Smith, B. D. (1995). The emergence of agriculture. New York, Scientific American Library:
Distributed by W.H. Freeman
• Trut, L. N. (1999). "Early Canid Domestication: The Farm-Fox Experiment."
American Scientist 87: 160-169
• Kukekova, et. al., (2008) Genome Research, 17 (3): 387-399
• Driscoll, C. A., D. W. Macdonald, et al. (2009). "From wild animals to domestic pets,
an evolutionary view of domestication." Proc Natl Acad Sci U S A 106 Suppl
• Driscoll, C. A. and D. W. Macdonald (2010). "Top dogs: wolf domestication and wealth." J Biol 9(2): 10
• Andersson, L. and M. Georges (2004). "Domestic-animal genomics: deciphering the genetics
of complex traits.“ Nat Rev Genet 5(3): 202-212
• Driscoll, C. A., J. Clutton-Brock, et al. (2009). The Taming of the Cat. Scientific American. 300: 68-75
• Driscoll, C. A., M. Menotti-Raymond, et al. (2007). "The Near Eastern origin of cat domestication."
Science 317(5837): 519-523.
• Lindberg et al., Current Biology vol 15 no 22
Animal Domestication
Dr. Carlos A. Driscoll
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References and further reading (2)
• Dawkins R (2003) The evolution of evolvability. On Growth, Form and Computers: 239–255
• Dawkins, R., 1989, The evolution of evolvability, in: Artificial Life, C. Langton (ed.) (Addison Wesley,
Santa Fe NM) pp. 201-220
• Galton, 1865 The first steps towards the domestication of animals. Transactions of the Ethnographical
Society of London Vol. 3 1865 p.122-128
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