Biology Chapter 11 Flashcards

Artificial vs. Natural Selection

• Artificial selection is driven by human preference, whereas natural selection is influenced by environmental conditions.

Evolution of Populations

• Evolving populations indicate changes in their genetic makeup over time.

Antibiotic Resistance

• MRSA (Methicillin-resistant Staphylococcus aureus) is a strain of skin bacteria resistant to methicillin, highlighting issues in treating bacterial infections.

Tuberculosis

• Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis and transmitted through sneezing.
• Symptoms include bloody cough, fever, chills, night sweats, fatigue, nail clubbing, and loss of appetite.
• Treatment involves isolation and antibiotic therapy.
• Prevention consists of vaccinations, proper patient treatment, and education on the disease.

Natural Selection Principles

• Not all species originated from a common ancestor; this statement itself is not part of natural selection theory.
• Increased reproductive success leads to the propagation of traits that enhance survival.

Mutations and Fitness

• A mutation resulting in an allele that reduces fitness will likely lead to fewer offspring for the affected individual.

Definitions

• Allele: A specific version of a gene.
• Fitness: Refers to the relative survival and reproduction of different variants within a population.

Observations in Natural Selection

• Individual variation exists within populations.
• Some variations can be inherited.
• Populations produce more offspring than can survive (overproduction).
• Survival and reproduction are influenced by advantageous traits.

Types of Selection

• Directional selection favors one extreme trait, such as the evolution of longer necks in giraffes.
• Stabilizing selection works favorably towards average traits.
• Diversifying selection focuses on extremes in traits.

Modern Synthesis

• Represents an integration of genetics and evolution, based on genetic principles that inform evolutionary processes.

Evolution and Adaptation

• Adaptations are traits that improve individual fitness in particular environments, shaping the dynamics of populations through various patterns of selection.

Testing Natural Selection

• Methods for testing include artificial selection and observing natural selection in laboratory and wild populations.

Darwin's Contribution

• Charles Darwin's work established that natural selection is a primary mechanism driving evolution.