Unit 5 - Human pop: past and present Flashcards
human pop
unlike other species, humans have increased the carrying capacity of their environment and, as a result, human pop has grown exponentially. In addition, humans r altering Earth in ways that might be detrimental to both humans and other pops
Human Pop Growth
HPG has some of the same characteristics as other pop, especially k-selected species. However, humans also alter their environment to a much greater extent than other species do
what is this dip
plague
Factors That affect growth
starting in the 1700s technological advances dramatically affected human pop growth and changed it from a logistic growth pattern to an exponential growth patter
(7) technological advances:
1) improved agricultural methods
2) domestications of animals
3) advancements in weaponary
4) breakthroughs in medicine
5) improved food storage and shelter
6) increase use of fossil fuels
7) expansion of geographic range
Exponential Growth
for the last 300y humans pop growth rate has benn 2% each year, but in recent years it reduced to 1.2%
calculate pop growth is to calc a pop doubling time
the time it takes the pop to double its number. at a growth rate of 1.2% per year, the world’s pop will double again in abt 58y. but not across the globe
Domestication of Plants and Animals
with the domestication of plants and animals, pop were transformed from small mobile groups of hunter-gathers into scientists in permanent villages and towns
crop cultivation
neutral environment was modified via irrigation and specilized CC
disease on rise; increase
pop density made it easier for disease-carrying organisms to spread
pathogen
a disease-causing agent such as a microbe or fungus
- only be sustained and evolve in high density pops
domestication of animals
contribute to the spread of pathogens, disease can jump from animals to humans
epidemic
the spread of disease beyond a v local pop
- large developed areas experienced the worst epidemics (due to pip density) but also developed resistance first
Industrial revoltion
was a period of great technological advancements from 1800s to 1900s during which machines were developed
- influences agriculture, manufacturing, mining, transportation, and technology profound effects on the socioeconomic and cultural conditions of time
- earth pop doubled
developments in chemistry
lead to the discovery to fertilizer and other compounds
- increase food production
- decrease labour needs
