Exam 1 Flashcards
1
Q
3 general stages of human-plant continuum
A
- wild plant food procurement (hunting/gathering, shifting agriculture/slash and burn)
- wild plant food production (minimal tillage)
- cultivation with systematic tillage
2
Q
stage 1 of human-plant continuum
A
- mainly foraging (examples: ginseng, pine nuts, chestnuts)
- some soil burning; protective tending (removing unwanted species)
- ecological effects: less competition, some soil disturbance
3
Q
stage 2 of human-plant continuum
A
- more sedentarism (local irrigation)
- minimal tillage
- includes weeding, transplanting, replacement planting if plants due out, seasonal harvesting
- example is rice fields!!
4
Q
slash and burn agriculture
A
- land burned, then used for 2-5 years
- land left fallow for up to 20 years, becoming secondary vegetation and eventually secondary forest
5
Q
changes in human society with agricultural developement
A
- increasing population density and sedentarism
- government developments
- increasing technology
6
Q
domestication vs agriculture
A
- domestication: genetic alteration/selection of useful traits
- agriculture: cultivation of plants (minimal or intensive)
7
Q
different origins of agriculture
A
- fertile crescent was 1st, around 11k years ago
- Yangtze and Yellow River basins
- New Guinea highlands
- central Mexico
- Northern S. America
- Eastern N. America
- Sub-Saharan Africa
8
Q
evidence for early agriculture
A
- human objects: hearths, pots, garbage dumps, tools, art
- skeletons and mummified remains, including teeth wear
- pollen fossils
- phytoliths
- carbon dating
9
Q
neolithic revolution
A
- origin of farming; 8000-6000 BC
- hunting and gathering transitioned to cultivation
- discovery of metal allowed sharper tools
- transition to more permanent dwellings (caves)
***occurred at many places at the same time!
10
Q
how did people begin to farm?
A
- people found desirable plants in the wild and collected fruits and seeds
- fruits and seeds were scattered at habitation sites
- desirable plants began to grow by settlements
- seeds were then collected and stored to grow more
11
Q
why was hunter/gatherer lifestyle superior compared to farming?
A
- Kung people in Kalahari desert only work 2.5 days per week
- alternatively, farmers more more hours and have worse health
- farming is a logical step when necessary, but many societies don’t fully do it
- it’s also possible for hunter/gatherers to be more sedentary
12
Q
agricultural changes from ice age
A
- after ice age, sea level stopped rising around 10k years ago
- stable costal plains and river valleys (oases with water) began to be settled
- warm, dry climate favored grains
13
Q
theories for origin of agriculture
A
- dump heap hypothesis: plants began growing at settlements from discarded plant matter
- cultural centers: people were sedentary first; turned to farming to avoid traveling far
- environmental determinism: humans outgrew resources and were forced to cultivate (environment determines our activities)
- coevolution: humans dependent on cultivated plants, but as they were artificially selected they also became dependent on humans (couldn’t live in wild)
- both population and climate pressure (Mark Cohen)
- 3 part hypothesis: 1) presence of plants good for domestication and caloric needs, 2) knowledge passed down, 3) decrese in landscape for hunting/gathering (all must be met)
14
Q
“Origin of Cultivated Plants”
A
- by Alphonse Candolle; first book investigating wild progenitors
- found that centers of origin have more varieties and genetic variation than the plants we cultivate
- Candolle identified 6 centers of origin, now 13 identified
15
Q
5 levels of domestication (for a specific plant species)
A
- unconscious selection of plants for desirable traits
- conscious cultivation of plants with desirable traits
- deliberate breeding to improve traits
- scientific breeding–genetic mechanisms known and exploited
- direct genetic manipulation
16
Q
how does domestication reduce genetic diversity?
A
- founder effect: only some varieties of plant brought to the new area (lacking many alleles)
- this causes genetic drift (change in frequency of alleles in the gene pool)
17
Q
wild plants, landraces, and cultivars
A
- wild plants are native plants in center of origin
- landraces are grown near center of origin, but only some desirable varieties of plant
- cultivars are grown away from center of origin; least diverse
18
Q
importance of diversity in potatoes
A
- Irish depended on potatoes bc they were calorically dense, but only grew one variety
- fungi destroyed most of the potatoes
- later, potatoes were crossed with native Andean varieties to make them resistant to fungi
19
Q
domestication of corn
A
- wild progenitors dispersed seeds by “shattering” but humans selected types that don’t shatter so they can collect seeds
- humans also selected for larger seeds
20
Q
characteristics of domestication syndrome
A
- compact growth (less shade, more space, more energy for fruit)
- short life cycle
- seed selection: threshing seeds (easier to gather), larger seeds, sometimes no seeds (vegetative growth)
- reduced dormancy
- increased seedling vigor
- specific spacing for pollination
- polyploidy
- phenotypic plasticity
21
Q
reduced dormancy in domestication syndrome
A
- wild plants have bet-hedging strategy: plants germinate at wider range of times so environmental factors won’t kill entire population
- domesticated plants have a very short germination period and couldn’t survive in wild
22
Q
increased seedling vigor in domestication syndome
A
- wild plants have fragile seedlings–why they are so prolific
- domesticated plants selected for stronger seedlings
