population dynamics. describes how pop. inc or d dd dec. immigration birth emmigration death
TRANSCRIPT
Remember a population…
group of organisms of the same species that live together in one place at one
time and interbreed.
Remember …
Population-Limiting Factors
• Density-independent factors
• Density-dependent factors
competition
small organism
Short life span
Produces many offspring
Rate Strategy
r-strategy
larger organism
Long life span
Produces few offspring
Carrying Capacity Strategy
k-strategy
Human Population Growth
The study of human population size, density, distribution, movement, and birth and death rates is demography.
Today, the world
population is more than 6
billion people and is
increasing.
Why so many Humans???? .
• Better sanitation and hygiene,
• disease control, • agricultural technology• Medicine/vaccines
As more humans live on the planet, more resources will be needed to support them. As demand for resources increases, more pressure will be put on Earth’s ecosystems.
You tricky tricky humans
• For thousands of years, environmental conditions kept the size of the human population in check.
• Humans have learned to alter the environment in ways that appear to have changed its carrying capacity.
Our own Carrying capacity?
• Sci are concerned about human popexceeding carrying capacity.
• resources from biosphere that are usedby each person.