Biology: Natural Selection and Plant Responses

Natural Selection

• Definition: Natural selection favors behaviors (innate or learned) that enhance survival and reproduction.
• Foraging Behavior:
• Key components: Searching for food, recognizing food, and capturing food.
• Successful foraging leads to better survival rates due to increased access to food resources, enhancing the ability to reproduce.

Mating Behaviors

• Types of Mating Systems:
• Monogamous: One male pairs with one female.
• Polygamous: One male mates with multiple females or one female mates with multiple males.
• Sexual Dimorphism:
• Difference in appearance between males and females as a result of sexual selection.
• Example: Male peacocks with vibrant feathers attract females, showcasing this dimorphism.

Cooperative Behavior

• Definition: Behaviors that enhance the fitness of a species by increasing survival rates of individuals within a population.
• Examples of Cooperative Behavior:
• Warning Calls: Used by species like zebras to alert others to danger, thus promoting group survival.
• Kin Selection: Individuals help relatives, increasing the overall fitness of shared genes.
• Altruism: Selfless behavior where individuals may sacrifice their own fitness for the benefit of others.
• Example: Naked mole rats where non-reproductive members protect the queen and kings, enhancing the survival chances for the entire colony.

Plant Responses to Environment

• Plants exhibit remarkable adaptations for survival, including:
• Phototropism: Growth response to light, allowing plants to grow towards or away from light sources.
• Photoperiodism: Plant response to day length affecting flowering times; certain plants bloom in specific seasons.
• Defenses Against Herbivory:
• Physical defenses such as thorns and trichomes, as well as chemical defenses including toxins to deter herbivores.

Communication Among Plants

• Chemical Communication: Plants can send volatile chemicals to warn neighbors of herbivore attacks, leading to synchronized defense responses.
• Example: Lima bean plants release chemicals when damaged, prompting neighboring plants to produce their own defenses against herbivory.

Soil Composition Effects

• Impact on Plant Traits: Soil pH affects flower coloration in plants;
• Example: Hydrangeas change color based on soil pH—acidic soils produce blue blooms, while basic soils lead to pink blooms.

Practical Application Scenario: Ravens Feeding Behavior

• Observation Scenario: Ravens feeding loudly on a carcass attract other ravens.
• Proximal Causes: Immediate reasons for behavior include attracting more birds to feed, based on learned behavior.
• Ultimate Causes: Long-term evolutionary benefits, such as increased food acquisition in groups.
• Comparison with Other Species: Other species may defend their food for reasons such as resource scarcity or aggressive territorial behavior, ensuring individual survival.