Population Biology

Sea otters eat sea urchins How does the # of otters in a community affect the # of urchins? How does the # of urchins in a community affect the # of otters?

Population: group of organisms, all same species, in an area Is population growth linear or exponential?

Population growth is exponential - as population gets larger, it grows at a faster rate J-curve graph

Limits to growth Populations can’t grow indefinitely Limiting factors - cause population growth to slow; ex: food availability, disease, predators, lack of space Carrying capacity - # of organisms of one species an environment can support predators disease space food

Life-history patterns Rapid-life history Reach maturity quickly Short life span Small bodies Unpredictable environments (affected by weather) Many offspring Flies, mosquitoes, gnats Slow-life history Reproduce slowly Long life span Large bodies Stable environment Few offspring in a lifetime Humans, pandas, elephants