27 - Agriculture

Niche construction definition

Organisms modify their environments in ways that change selective pressures

Why niche construction matters

It shapes the evolutionary context for humans and other species

Cognitive niche definition

Human ability to adapt using social learning technology and cooperative culture

Generalist specialist meaning

Humans specialize in learning and adapting to many environments

Cognitive niche consequence

Allowed humans to colonize nearly the entire world before agriculture

Extinction pattern with humans

Humans contribute to extinction of large slow animals but avoid extinction by switching prey

Americas entry timing

Humans entered the Americas around 25 thousand years ago

White Sands footprints

Footprints from 23 to 21 thousand years ago show early presence in New Mexico

Caribbean settlement timing

Humans reached the Caribbean between 5 thousand and 1 thousand years ago

Polynesia settlement timing

Humans reached Polynesia between 3 thousand and 1 thousand years ago

Holocene start pattern

By 10 thousand years ago humans were distributed globally

Forager definition

People who hunt gather and forage for wild foods

Agriculture definition

Cultivation of plants and rearing of animals using new technologies

Neolithic Revolution timing

Began around 12 to 10 thousand years ago

Domestication definition

Humans modify genetic makeup of plants and animals through artificial selection

Dogs domestication timing

Dogs were domesticated around 23 thousand years ago in Siberia

Multiple domestication centers

Agriculture began independently in several regions of the world

Sedentism cause

Stable food production encouraged people to settle permanently

Agriculture fertility effect

Farmers have increased fertility because frequent nursing suppression is reduced

Pros of agriculture food stability

Agriculture provides stable food medicine and by products

Cons of agriculture reduced diversity

Agricultural diets reduce diversity and parasite resistance

Pros of agriculture population growth

Stable food increases population size and supports sedentism

Cons of agriculture waste issues

Sedentism creates waste accumulation and pollution

Pros of agriculture specialization

Food surplus enables specialization of labor

Cons of agriculture inequality

Surplus leads to wealth differences and social stratification

Pros of domesticates

Niche expansion through transport food secondary products and companionship

Cons of domesticates

Increased exposure to pathogens and landscape damage

Distributed cognition definition

Knowledge spread across a community rather than within individuals

Agriculture inevitability

Agriculture is not inevitable and societies cannot easily revert after sedentism

Amylase gene adaptation

Increased amylase copies evolved to digest starch rich agricultural diets

Lactase persistence adaptation

Evolved in populations with dairying traditions

Agriculture and malaria

Forest clearing created mosquito habitats leading to selection for sickle cell allele

Holocene dependence

Human civilization relies on domesticates adapted to stable Holocene climate

Anthropocene meaning

Current era shaped by human environmental impact

Inheritance mechanisms

Genetic epigenetic cultural and environmental inheritance

Course takeaway science

Science is a process of inquiry not a single discovery

Course takeaway chimp misconception

Humans did not evolve from chimpanzees but share a common ancestor

Course takeaway ongoing evolution

Humans are still evolving under selective pressures

Course takeaway inheritance types

Humans inherit through genetic epigenetic cultural and niche construction pathways

Course takeaway race

Race is not a biological category but racism has real biological effects

Course takeaway human DNA

Humans share about ninety nine percent of their DNA

Course takeaway variation

Human genetic variation is clinal and shaped by global expansions