BIOL1003 Lecture Notes - Lecture 19: Sodium Fluoroacetate, Ecological Succession, Secondary Succession
Future reproduction over current reproduction
• Competition
• Dominance
• Not enough resources
• Disturbance
• Change is season
• In competition
E.g. Beavers might have to put off reproduction until they have the right environment
built —> dam
Current reproduction over future reproduction
• Under density independent growth conditions
• Ecological succession
◦ Primary succession occurs where no soil exists when succession begins
◦ Example:
▪ Glacier in Alaska —> pioneer plants —> forest, over time
◦ Secondary succession begins in an area where soil remains after a disturbance
(quicker rejuvenation)
• In-determinant growth (fish, growing big could be risky)
◦ More susceptible to predation —> slower
• When there is no going back
◦ Atlantic Salmon return from marine to freshwater rivers to reproduce
◦ Some don’t swim to their place of spawning —> genetic mixing
• Antechinus
◦ Males mate for two week period
◦ Males then die within two weeks of mating- dies before young are born
◦ Very risky, demanding
◦ Provides more resources for females and offspring
◦
• Tequila plant is being harvested before they produce flowers because flowers take
energy away from heart of the plant—> no cross pollination —> genetic risk
Human population
• Growth rate is decreasing
• Increase in life expectancy: access to health, education, resources, food
Population demography
• Ecology and evolution interact to produce suites of life history traits
• These influence age structure and growth of populations
• Humans are not exempt from these influences
◦ Population pyramids
Food biosecurity
• Introduction of rabbits —> large problem —>
◦ Rabbit proof fence
◦ 1080 poison (bio accumulates)
Document Summary
Future reproduction over current reproduction: competition, dominance, not enough resources, disturbance, change is season, in competition. Beavers might have to put off reproduction until they have the right environment built > dam. Current reproduction over future reproduction: under density independent growth conditions, ecological succession. Primary succession occurs where no soil exists when succession begins. Glacier in alaska > pioneer plants > forest, over time. Secondary succession begins in an area where soil remains after a disturbance (quicker rejuvenation) Atlantic salmon return from marine to freshwater rivers to reproduce. Some don"t swim to their place of spawning > genetic mixing: in-determinant growth (fish, growing big could be risky, when there is no going back, antechinus, tequila plant is being harvested before they produce flowers because flowers take. Males then die within two weeks of mating- dies before young are born. Provides more resources for females and offspring energy away from heart of the plant > no cross pollination > genetic risk.
