Unit 2 Learning Objectives - Biology 150 Fall 2025

These flashcards summarize key concepts from the Unit 2 Learning Objectives for Biology 150, covering topics in evolution, natural selection, genetic processes, and species concepts.

What is typological thinking and what is the significance of Aristotle's 'great chain of being'?

Typological thinking is the belief that species have a fixed essence and varies little over time. Aristotle's 'great chain of being' represents a hierarchical structure of life, placing organisms in a ranking system from lower to higher forms.

How did Aristotle’s ‘chain of being’ differ from Plato’s views?

Aristotle's 'chain of being' emphasizes a hierarchical organization of life forms, whereas Plato's views focus on ideal forms, suggesting that the material world is a reflection of a higher, immaterial reality.

What were Lamarck’s hypotheses of use and disuse?

Lamarck proposed that organisms develop or reduce certain traits based on their use or disuse, and that these changes could be inherited by future generations.

How did Darwin and Wallace revolutionize evolutionary thought?

They introduced the idea of natural selection as a mechanism of evolution, contrasting with previous beliefs that emphasized fixed species and simple variation.

What is evolution and how can we determine if a population has evolved?

Evolution is the change in the heritable traits of biological populations over successive generations. We can determine if a population has evolved by examining changes in its gene pool.

What does the Hardy-Weinberg equilibrium predict?

The Hardy-Weinberg equilibrium predicts allele and genotype frequencies in a population under specific conditions, assuming no evolution occurs.

What is genetic drift and how does it lead to evolution?

Genetic drift is a mechanism of evolution that causes allele frequencies to change due to random sampling of organisms, particularly significant in small populations.

What are mutations and how can they lead to evolution?

Mutations are random changes in the DNA sequence that can generate genetic variation in a population, influencing evolutionary processes over time.

What is gene flow and its effect on evolution?

Gene flow is the transfer of genetic material between populations, which can alter allele frequencies and increase genetic similarity between populations.

What are the three types of non-random mating?

The three types of non-random mating are assortative mating, disassortative mating, and inbreeding.

What is natural selection and its requirements?

Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring. Its four requirements are variation, heritability, differential survival, and reproduction.

What misconceptions exist about natural selection?

Misconceptions include beliefs that natural selection changes individuals, is goal-oriented, leads to perfection, and is the only evolutionary mechanism.

What is sexual selection?

Sexual selection is a form of natural selection focused on mate choice and competition among individuals of the same sex for mating opportunities.

What are the outcomes of secondary contact between diverging populations?

Outcomes include fusion, reinforcement, hybrid zone formation, and hybrid speciation, depending on various biological and environmental factors.

What is macroevolution?

Macroevolution refers to large-scale evolutionary changes that occur over geologic time, including the emergence of new species and the patterns of diversification.

What evidence supports the change of species over time?

Evidence includes the fossil record, transitional fossils, and the existence of vestigial structures.

What characterizes monophyletic, polyphyletic, and paraphyletic groups?

Monophyletic groups include an ancestor and all its descendants; polyphyletic groups include species with different ancestors; paraphyletic groups include an ancestor and some, but not all, of its descendants.