Evolutionary Theories and Ecological Concepts: A Comprehensive Guide

Evolutionary Theories

Punctuated Equilibrium vs. Neo-Darwinism vs. Neutralism

• All three theories propose evolutionary change.
• Punctuated Equilibrium: Evolutionary changes occur rapidly and abruptly.
• Neo-Darwinism: Evolutionary changes occur gradually over time.
• Neutralism: Most mutations have no effect on natural selection.

Barriers to Genetic Isolation

• Geographical
• Sexual
• Physiological
• Chromosomal
• Ethological

Ecological Concepts

Abiotic and Biotic Factors

• Abiotic Factors: Non-living factors that affect ecosystems (e.g., temperature, pH, wind)
• Biotic Factors: Living components that affect ecosystems (e.g., disease, predation, competition)

Biomass

- Total dry weight of organic matter in organisms or ecosystems. - Includes carbohydrates, proteins, etc.

Ecosystems Without Bacteria and Fungi

- Dead organic matter would not be recycled. - Plants would lack sufficient nutrients.

Ecosystems Without Autotrophic Organisms

- No primary producers. - Life would be impossible.

Oil and Natural Gas Formation

- Decay of marine organisms on the ocean floor. - Anoxic conditions prevent decomposition. - Compacted and heated organic matter forms oil and gas.

Nitrogen Cycle

1. Nitrogen-fixing bacteria
2. Nitrifying bacteria
3. Denitrifying bacteria

Secondary Succession

- Faster than primary succession. - Populations start with soil, spores, and seeds.

Ocean Acidification

- Increased dissolved carbon dioxide lowers ocean pH. - Fewer carbonate ions for calcification. - Thinning of calcium exoskeletons. - Coral bleaching