Wk 9

Differences in Traits

• Homologous traits are inherited from a common ancestor and may serve different functions, e.g., human arm vs. bat wing.
• Analogous traits serve similar functions but do not share a common ancestor, such as butterfly and bird wings.

Evolution Types

• Convergent evolution leads unrelated species to develop similar traits due to environmental pressures, e.g., dolphin and shark body shapes.
• Divergent evolution occurs when species evolve in different directions from a common ancestor, exemplified by Darwin’s finches with varying beak shapes.

Lamarck's Theory

• Lamarck theorized organisms could pass on acquired traits; giraffes supposedly inherited long necks from ancestors that stretched their necks.

Geological Principles

• Uniformitarianism posits that Earth's features developed through ongoing processes like erosion and sedimentation.
• Catastrophism suggests Earth's features were shaped by sudden violent events like earthquakes and floods.

Darwin's Insights

• Natural Selection describes evolution via advantageous traits becoming common through survival and reproduction.
• Common ancestry implies all species descended from shared ancestors, diverging over time to create biodiversity.

Darwin's Concepts

• Perpetual Change indicates the world is constantly evolving, as recorded in the fossil record.
• Multiplication of Species refers to species splitting into more species over time, driving biodiversity through speciation.
• Gradualism suggests evolutionary changes occur slowly over long periods, opposing the idea of sudden large-scale changes.

Selection Processes

• Natural Selection occurs without human intervention, driven by environmental pressures.
• Artificial Selection involves human-led breeding for desired traits, such as in dog breeding or crop selection.

Aspects Not Addressed by Darwin

• Genetics and the mechanisms of inheritance weren't understood during Darwin's time; DNA discovery came later.
• Epigenetics explores gene expression changes without altering genetic code, influenced by environmental factors.

Types of Evolution

• Microevolution involves small gene frequency changes within a population over time.
• Macroevolution addresses large-scale changes in gene frequencies that can determine new species.

PCR Applications

• Medical Diagnostics: PCR detects pathogens in clinical samples, crucial for diagnosing diseases like COVID-19, HIV, and TB.
• Genetic Research: Identifies genetic alterations related to disorders such as cystic fibrosis and sickle cell anemia.
• Forensic Science: PCR aids in DNA profiling for suspect identification and paternity testing through DNA comparison.
• Biotechnology: Utilized for gene cloning, genetic engineering, and sequencing DNA for research purposes.
• Environmental Science: Detects microorganisms in samples and studies genetic diversity in ecosystems.
• Agriculture: Identifies genetically modified organisms in food based on pathogen detection.
• Personalized Medicine: Pharmacogenomics uses PCR to tailor treatments based on genetic variations affecting drug responses.

This quiz explores key concepts related to evolution, including speciation, natural versus artificial selection, and the scale of evolutionary changes. It also touches on the advancements in genetics that emerged after Darwin's time, including techniques like PCR. Test your understanding of these fundamental biological principles.