Learning outcomes

1. Learning outcomes • Describe the 5 interspecific relationships and the effect they have on each partner of the relationship • Explain what happens to the population and individual when intraspecific competition takes place

2. Interrelationships

3. Intraspecific relationships • Relationships between organisms of the same species • Very strong interactions • Co-operative • E.g. Courtship, looking after young, hunting in packs • Aggressive • E.g. Fighting for mates and territories

4. Interspecific relationships • Relationships between organisms of different species • 5 main relationships

5. Mutualism Both partners benefit from the relationship

6. Commensalism • One partner benefits while the other partner is in-different

7. Amensalism • The presence of one species has a harmful effect on the other, but is not affected by the association itself

8. Antibiosis • One partner is harmed while the other partner is in-different

9. Exploitation • One member of the partnership benefits while the other is harmed

10. Overview A B Mutualism Commensalism Antibiosis Amensalism Exploitation Benefits Benefits A B Benefits Not affected A B Benefits Harmed A B Not affected Harmed A B Harmed Benefits

11. Activity • Complete pg 309 in Biozone

12. Intraspecific Competition • Members of the same population have the same resource requirements from the environment • What are these resources? • What happens when these resources are limited?

13. When resources are limited • Populations - reduce their population growth rate (lower birth rates and/or higher mortality) • Individuals – reduce their growth rate and mature at a smaller size, some may not breed

14. Intersepcific Competition • Competitive exclusion principle (Gause’s principle) “No two species with similar needs for the same limiting resources can coexist in the same place.” • Window and Notch caterpillars