BIOL EVOLUTION EXAM 4

What is the significance of natural selection in the theory of evolution?

Natural selection explains how heritable traits that increase an organism's fitness are passed on to successive generations, driving evolution.

Why is evolution considered one of the five key attributes of life?

Populations of organisms evolve over time, demonstrating a fundamental process of life.

How did Charles Darwin's observations aboard the HMS Beagle influence his understanding of life's diversity?

Darwin observed variations among species, fossils, and environmental adaptations, leading him to question traditional beliefs about species' immutability.

What role did the Galápagos Islands play in shaping Darwin's ideas?

Darwin noted that species varied between islands and adapted to their habitats, influencing his theory of natural selection.

How did fossils contribute to Darwin's conclusions about evolution?

Fossils showed gradual changes in species over time and revealed connections between extinct and extant species.

What influence did the work of James Hutton and Charles Lyell have on Darwin’s thinking?

Hutton's and Lyell's ideas on Earth's ancient and dynamic nature led Darwin to consider that life could also change over time.

How did Lamarck’s theory of evolution differ from Darwin’s?

Lamarck proposed that acquired traits during an organism's lifetime could be passed to offspring, whereas Darwin emphasized natural selection acting on inherited variation.

What is the principle of the “inheritance of acquired characteristics,” and how does it relate to Lamarck's ideas?

Lamarck suggested that traits acquired in response to environmental challenges are passed to offspring, a concept now disproven.

What did Thomas Malthus’s essay contribute to Darwin's concept of the “struggle for existence”?

Malthus highlighted the competition for limited resources in crowded populations, which Darwin applied to natural populations.

What are Darwin's four postulates, and how do they explain natural selection?

(1) Variation exists in populations, (2) Traits are heritable, (3) More offspring are born than survive, (4) Individuals with favorable traits reproduce more successfully.

How do fitness and adaptation relate to natural selection?

Fitness measures reproductive success; adaptations are heritable traits that enhance fitness.

How does artificial selection differ from natural selection, and how did Darwin use this in his research?

Artificial selection involves human choice in breeding for desired traits, which Darwin used to illustrate natural processes of selection.

What does the fossil record reveal about the gradual change of species over time?

It shows transitions between species and documents evolutionary changes.

How does radiometric dating help determine the age of fossils and rocks?

By measuring radioactive decay, it provides precise ages for geological layers and the fossils within.

What are homologous and vestigial structures, and how do they support the theory of evolution?

Homologous structures indicate common ancestry; vestigial structures show evolutionary remnants of functional traits.

How do biogeography and continental drift provide evidence for evolution?

Geographic distribution and historical landmass movements explain similarities and differences among species.

What is "industrial melanism," and how does it serve as an example of natural selection?

The prevalence of darker moths during the industrial revolution due to environmental changes illustrates natural selection.

How do variations in finch beak sizes and shapes illustrate natural selection on the Galápagos Islands?

Beak variations adapted to specific food sources show how traits evolve in response to environmental pressures.

How do similarities in early embryonic development among different species support evolutionary theory?

Shared embryonic features suggest common ancestry.

What is the significance of molecular data, like DNA and proteins, in understanding evolutionary relationships?

Molecular similarities reveal genetic connections and evolutionary history among species.

Why was Darwin’s theory of natural selection controversial at the time of its publication?

It challenged religious views of creation and the immutability of species.

How has modern biology expanded or refined Darwin’s original ideas?

Advances in genetics and molecular biology have provided detailed mechanisms for inheritance and variation.

What role does environmental pressure play in shaping species through natural selection?

It determines which traits enhance survival and reproduction, driving adaptation.

How can the concept of “descent with modification” be observed in current populations?

Changes in traits within populations over generations, such as antibiotic resistance in bacteria, exemplify this concept.