BIOL 290 Lecture Notes - Lecture 1: Permafrost, Food Web, Theodosius Dobzhansky
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Humans have changed the Earth
Thursday, September 6, 2018
9:05 PM
• Humans have changed the Earth
• Pollutants
• Green house gasses
• Co2 level increase
• Sea level changes
• Sea water acidic changes (can cause major disturbances in aquamarine life development);
can also cause dissolving habitats in the ocean
• Endocrine disruptions: hormonal disruptions from pollutants like BPA
Climate Impacts on Ecosystems
• Timing of seasonal life cycle events
• Ex: In 2010 & 2012 plants in Eastern U.S. flower buds produced flowers earlier than ever
• Range shift: species move north because of sea changes
• Food web disruptions: reduced production in oceans that are in areas where temperature
of the ocean has increased
• Melting permafrost: deep layer of ground, that remains permanently frozen all year round;
when it melts it releases methane because plant life has been captured in the ice over the
years
• Higher extinction risks
Pathogens, Parasites and Diseases
• Malaria
• Higher/ longer transmission seasons with higher temperatures
• Shift change risks: malaria carrying mosquitos can move further North with warming
temperatures
Threshold Effects
• Biological changes are not necessarily gradual. A system may be stable up to a threshold
level then shift rapidly
• Not linear
Links between change, evolution and population
biology
• Adaptations
• Genes