Transcript Unexpected Consequences: The Black Death

The Black Death
Human Population
Industrialization
Agriculture
Huntergatherers
• Crowd diseases:
– Parasites, e.g. schistosomiasis
– Contagious diseases, e.g. measles
• Epidemics
• Domesticated animals
Rinderpest
Measles
The Biology of Plague
• Endemic disease, Epidemics and Pandemics
• The Three Great Pandemics
th
6
and
th
7
Centuries AD
The Medieval Pandemic
The Modern Pandemic
The Biology of Plague
• Bacillus: Yersinia
pestis
The Biology of Plague
• Rattus rattus (Black
Rat)
The Biology of Plague
• Flea: Xenopsylla
cheopis
Types of Plague
• Primary Bubonic
– Transmitted by fleas
– Buboes
– 60-90% mortality
Types of Plague - 2
• Primary bacteraemic
(septicaemic)
• Secondary
bacteraemic
• Primary pneumonic
• Secondary pneumonic
– Transmitted by airborne droplets
– Not too infectious
The Black Death
•
•
•
•
Origins in Central Asia, ca. 1331-1332
Slow rate of spread
Importance of Mongol Empire
Spreads from Tatars to Genoese colony of
Caffa
• From there to Europe in September 1347
How Many People Died?
How Many People Died?
Death Rates of English Parish Priests
100
90
80
60
50
40
30
20
10
Diocese
ich
r
No
rw
r
nc
he
s te
Ex
e te
Ely
Wi
Lic
h
fi e
ld
Ba
th/
We
lls
0
Yo
rk
Percentage
70
Burials at Givry, 1334-1348
700
600
400
300
200
100
Year
47
13
45
13
43
13
41
13
39
13
37
13
35
0
13
Burials
500
How Many People Died?:
Conclusion
• Ca. one-half of
population dies
• Population declines
until ca. 1425, when
stabilizes at one-third
level of that of 1300
• Remains at this low
level until ca. 1475
• Returns to level of
1300 around 1600
But Was It Plague?
But Was It Plague?
• Two types of rat
needed
• Rattus norvegicus
(brown rat) did not
reach England until
1700s
But was it plague?
• Plague a disease of open steppes, and/or
warm countries, but
• Spreads to Iceland and Greenland
• No reports of dead
rats
• 40 day disease cycle,
as opposed to 7-10
days for plague
Or a Viral Hemorrhagic Fever?
• Characterized by
bleeding and vomiting
of blood
• Generalized necrosis
• Affected domestic
animals
• Spread from human to
human
Population Movement at Prato
Consequences
• Western Europe: “Golden Age” of the
Peasantry
– Rents decline
– Wages rise
– Serfdom disappears in W. Europe
Population Movements: England
Consequences - 2
• Intensifies political and social conflict
– “Seigneurial reaction”
– Peasant revolts/urban worker revolts
– Increased competition among aristocrats for
control of shrinking numbers of peasant,
leading to
• Increased civil war
• Increased inter-state war