Foundations of Evolution and Darwinism

What did people believe about the Earth and its creatures before the mid-1700s?

They believed in Creation, that the Earth and planets were only a few thousand years old, and that nothing had changed since their creation.

Who was Hutton and what was his hypothesis about the Earth?

Hutton was a geologist who proposed in 1795 that the Earth is much older than a few thousand years, suggesting that natural forces like erosion shape the Earth over time.

What is uniformitarianism?

The concept that rates of geological change are constant over time, implying that the processes observed today also occurred in the past.

What contributions did Lyell make to geology?

Lyell wrote about volcanoes and earthquakes changing landscapes, supporting the concept of uniformitarianism.

What was Lamarck's hypothesis regarding evolution?

Lamarck proposed that organisms evolve towards perfection, adapting to their environment, and introduced ideas like the inheritance of acquired traits.

What did Malthus contribute to the understanding of population growth?

Malthus suggested that human populations grow until resources become scarce, leading to competition, war, famine, and disease.

What key insights did Darwin gain from his trip to the Galapagos Islands?

Darwin concluded that the Earth is much older, organisms change over time, inherit changes, and that competition drives evolution.

What is artificial selection?

Artificial selection is the process by which humans breed plants and animals for desired traits.

What are the three parts of natural selection according to Darwin?

1. Struggle for existence through competition; 2. Survival of the fittest; 3. Descent with modification.

What does 'survival of the fittest' mean?

It refers to the idea that organisms best adapted to their environment are more likely to survive and reproduce.

What is descent with modification?

The concept that each generation passes on superior traits to the next generation, suggesting a common ancestor.

What evidence supports macroevolution?

1. Fossil record showing descent with modification; 2. Geographic distribution of related organisms; 3. Homologous structures; 4. Comparative embryology.

What are transitional fossils?

Fossils that show intermediate forms between different groups of organisms, providing evidence for evolution.

What is the significance of the Galapagos finches in evolutionary studies?

They demonstrate how related organisms can adapt to different environments, leading to speciation.

What are vestigial organs?

Non-functioning organs that are remnants of ancestors, providing evidence for evolution.

What is comparative embryology?

The study of similarities in embryonic development across different species, suggesting a common ancestor.

What is the law of thermodynamics in relation to evolution?

It states that systems tend to move towards disorder (entropy), which challenges the idea that complexity increases naturally.

What is the gene pool?

The total collection of genes and alleles in a population.

What is allele frequency?

The measure of how common a particular allele is within a population.

What are the sources of genetic variation?

1. Mutations; 2. Gene shuffling during meiosis; 3. Gene transfer; 4. Other factors like epigenetics.

What is the founder effect?

A phenomenon where a new population is established by a small number of individuals, leading to reduced genetic diversity.

What is the bottleneck effect?

A sharp reduction in population size due to environmental events, leading to a loss of genetic diversity.

What are the five conditions of the Hardy-Weinberg principle?

1. Random mating; 2. Large population size; 3. No immigration/emigration; 4. No mutations; 5. No natural selection.

What are the types of reproductive isolation?

1. Geographic; 2. Behavioral; 3. Temporal; 4. Mechanical; 5. Physical.

What are the types of natural selection?

1. Directional selection; 2. Stabilizing selection; 3. Disruptive selection.