Lecture 15: Competition 1 - October 13th

Good Morning: Instructor checks in with students after a break.
Exam 2: Scheduled for next Wednesday (not this Wednesday).
- Resubmissions for Exam 1: Will be checked today until Wednesday.
- Exam Key: Will be posted after resubmissions, allowing students to check their answers with the final grading.
- Corrections Timeframe: Students have two weeks after the exam to discuss any grading issues.
Final Paper Discussion:
- Specifics about the final paper will be addressed, but the discussion will not dominate today's lecture, which focuses on the upcoming exam and the topic of interspecific interactions.
- No final in-person exam; students will simply submit this final paper for their grade.

Main Focus: Interspecific interactions, particularly competition.
Lecture Schedule:
- Today: Competition and possibly predation (if time permits).
- Following lectures will continue exploring these topics leading up to Exam 2.

Interspecific vs. Intraspecific Competition: Highlighted importance of differentiating between these two types.
- Intraspecific Competition: Discussed in past lectures; refers to competition among individuals of the same species.
- Interspecific Competition: Focus of today's lecture, referring to competition among different species.

Niche Definitions:
- Fundamental Niche: Theoretical space with many dimensions representing environmental conditions that allow survival and reproduction for a species.
- Realized Niche: Actual space occupied by a species, reduced by competition with other species.
- Comparison:
- The fundamental niche includes all potential resources a species could utilize in an ideal situation.
- The realized niche accounts for limitations imposed by the presence of competing species.

Students should:
- Understand definitions of both types of niches.
- Learn how to measure and relate these concepts to others previously covered.
- Recognize links to demographic processes such as survival, reproduction, and population growth.

Physiological and Biotic Filters: Affect the realization of the niche.
Effects of Resources: Resources can facilitate population growth, contrasting with filters that limit populations.
Key Graphs & Illustrations: Concepts will be emphasized through graphs and models to differentiate between fundamental and realized niches visually.

Fundamental Niche Definition: An imaginary space with many dimensions where each axis represents a range of environmental conditions that allow species survival, growth, and reproduction.
Realized Niche Definition: Space representing resources available reduced due to competition with other species.

Population Growth: Changes due to competition among individuals of the same species.
Logistic Growth Model: Describes how populations grow and stabilize over time, incorporating carrying capacities (k).
- An observed growth pattern showcasing initial exponential growth that eventually levels off due to resource limitations and competition.

Impact of Intraspecific Competition on Realized Niche: Intraspecific competition does not change how a species exploits resources but affects population regulation.
Exam Question: Does intraspecific competition affect the realized niche?|NO, it doesn’t affect the imaginary space of resource exploitation for a species.|\

Key Concept: A more nuanced understanding reveals that species do adapt their niches based on competition, leading to morphologically, physiologically, and behaviorally inspired adaptations over evolutionary time.

Two Species Interaction: When two species compete, they exert negative effects on one another's growth and reproductive success.
Measurement of Effects: Reduction in fecundity, survivorship, and/or growth noticed when two different species interact.

Gauss (1934) Paramecium Experiment: Laboratory demonstration showing that when competing species of protists were placed together, one would eventually dominate and lead to exclusion of the other.
- Graphs Analyzed: Display separate growth rates of species when grown alone versus together, illustrating interspecific competition effects.

Definition: States that when two species are placed together competing for the same resource, one will always outcompete the other.
Coexistence in Varying Contexts:
- Natural Species Instantiation: Example with mongoose species showcasing ecological release when one competitive pressure removed leads to increased size parameters in the less dominant species.

Natural Selection in Action: Through the presence of competitors, species will shape their morphological traits accordingly to minimize competition.
Character Displacement vs. Ecological Release: Focusing on species adaptation dynamics, where removal of competition leads to optimal ecological niche realization over time.

Summary of Interspecific vs. Intraspecific Competition: Types of competition with illustrations.
Next Class Focus: Move deeper into understanding interspecific competition dynamics and applicable examples, including further lab experiments to define coexistence and resource partitioning among competitors.