Dept of Biology, Lewis and Clark College		Dr Kenneth Clifton
	Biology 141 Lecture Outline

Human Ecology and the rise of "conservation biology"

Thinking about human ecology and human impacts upon the environment.

Evolutionary history of human presence on the landscape.

1) origins in Africa

2) dispersal

3) the hunter/gatherer lifestyle: nomadism, opportunism, generalist feeding, pursuit of migratory game.

The Hadzabe give insights to hunter/gatherer societies.

In areas of less abundant/persistent resources, what do you expect in terms of pop size?

Is there a carrying capacity?

The development of agriculture (11,000 yrs ago) across the planet (end of last ice age)

What are the potential impacts of a more sedentary life?

Introduced species

Deforestation

Changes to soil condition

Pollution

Increased population size (relatively small until 3,000 - 2000 yrs ago)

Pop ~ 1 billion in 1800

Today ~7.5 billion (and rising!)

Historic patterns of population growth and projections for the future

What is happening to K?

What is K without impact on other species (extinctions and habitat degradation)? Estimated to be ~ 2 billion

What is absolute K? ~ 50 billion! Would require all available energy be devoted to human life (no luxuries)

What is “cultural K”? Should this be a goal of humanity? How do you manage such a goal?

MDCs vs LDCs (mostly vs less developed countries).

Look at human demography:

How did MDCs get to that status (in the last 200 years)?

The "industrial revolution"

Why the shift to slower population growth in MDCs (a transition from lots to fewer babies).

The demographic transition: Pre industrial, Early industrial, Late industrial, Post industrial

Stage	Birth Rate	Death Rate	Population change
Pre-industrial	High	High	Stable
Early-industrial	High	Dropping	Growing, increasingly fast
Late-industrial	Dropping	Low	Growing, increasingly slow
Post-industrial	Low	Low	Stable or declining slowly

 

 

Given all this, is there a need for the study of human impacts? This is often called conservation biology

Most conservation issues ultimately revolve around issues of preserving biological diversity

Three levels of biodiversity

genetic

species

ecosystem

Estimates of biodiversity are not easy to obtain

Natural vs. anthropogenic extinction

Historical patterns

 

Modern patterns

Is there a reason for modern species loss?

The correlation with human population growth

 

Revisiting species loss: HIPPO

 

Habitat alteration

Invasive species

Population growth

Pollution

Overexploitation

 

Why biodiversity matters

Ecosystem function

Diversity begats diversity

Opportunities for learning

Human health issues

Tourism/Recreation

 

Conservation Biology.... a field to address the loss of bio diversity

Preserving endangered species or the habitats that contain them?

Umbrella species and other ways of preserving groups of species

Community based conservation

What about setting aside areas for preservation or protection