Darwin and Wallace: Evolution and Natural Selection

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Which scenario best illustrates Darwin's concept of natural selection leading to evolutionary change?

A flower species exhibits a sudden mutation resulting in a change in petal color, immediately attracting a new pollinator and causing a rapid shift in the species' reproductive strategy.
A group of mammals is introduced to a zoo, where they are provided with a controlled diet and environment, leading to increased longevity and a decrease in genetic diversity.
A population of birds migrates to a new island with abundant resources, leading to an increase in the overall population size without any significant changes in beak morphology.
In a population of fish, individuals with slightly faster swimming speeds are better able to escape predators and, over generations, this trait becomes more prevalent. (correct)

How did the work of Thomas Malthus influence Darwin's theory of evolution?

Malthus's essay suggested a mechanism for genetic inheritance, which Darwin integrated into his theory to explain how favorable traits are passed on to future generations.
Malthus's essay highlighted the potential for overpopulation and the resulting struggle for resources, informing Darwin's concept of 'survival of the fittest'. (correct)
Malthus discovered fossil evidence of extinct organisms, which Darwin used to support his argument for the transmutation of species over time.
Malthus's provided Darwin with data on the geographical distribution of species, which helped Darwin correlate environmental factors with evolutionary adaptations.

What was the primary reason for Darwin's delayed publication of On the Origin of Species?

Darwin lacked sufficient evidence to support his hypothesis until the rediscovery of Mendel's work on genetics in the early 20th century.
Darwin was hesitant to publish because his theory of evolution by natural selection contradicted prevailing religious and social beliefs. (correct)
Darwin was waiting for Alfred Russel Wallace to independently publish his findings first, ensuring that Wallace would receive full credit for the theory of evolution.
Darwin was primarily focused on his research in geology and delayed publication to complete his comprehensive study of the geological formations of South America.

How did Darwin's observations of Galápagos finches contribute to his theory of evolution?

They illustrated adaptive radiation, where a single ancestral species diversifies into multiple species with specialized traits suited to different ecological niches. (A) Signup and view all the answers

Which statement explains the relationship between individual variation and natural selection?

Individual variation provides the raw material upon which natural selection acts, leading to differential survival and reproduction. (C) Signup and view all the answers

Which statement best explains why Darwin highlighted the 'rejection of injurious variations' alongside the 'preservation of favorable variations' in his definition of natural selection?

To underscore that natural selection acts as both a constructive and a destructive force, with the removal of harmful traits being as crucial as the spread of beneficial ones. (A) Signup and view all the answers

How did Alfred Russel Wallace's work in the Amazon and Malay Archipelago contribute to the understanding of biogeography and evolutionary processes?

Wallace's extensive documentation of species distributions helped define biogeographical regions and highlighted the role of geographical barriers in species divergence. (C) Signup and view all the answers

Which factor most directly fostered Darwin's early interest in natural history during his time at Cambridge?

His friendship with John Henslow, which cultivated his interest in the field. (C) Signup and view all the answers

Given that both Darwin and Wallace independently developed similar ideas about natural selection, what does this suggest about the nature of scientific discovery?

Scientific discoveries often emerge when the existing evidence and prevailing intellectual climate are ripe for a new synthesis or interpretation. (A) Signup and view all the answers

How did Darwin's voyage on the HMS Beagle specifically influence the development of his evolutionary theory?

It exposed him to a wide range of geological formations, flora, and fauna leading to observations that supports species diversification. (B) Signup and view all the answers

If a population of finches exhibits variation in beak size, with some having small beaks suitable for eating small seeds and others having large beaks suitable for eating large seeds, what would be the most likely outcome if the environment experienced a prolonged period of drought, leading to a scarcity of small seeds?

The finches with small beaks would be more likely to die off or have reduced reproductive success, while finches with large beaks would thrive, leading to a shift in the population's beak size distribution. (A) Signup and view all the answers

How does the concept of the 'Wallace Line' contribute to our understanding of the relationship between evolution and geography?

The Wallace Line illustrates how geographical barriers can isolate populations, leading to divergent evolutionary paths and the formation of distinct biogeographical regions. (B) Signup and view all the answers

What was the most significant impact of Darwin's publication, On the Origin of Species, on the scientific community and society at large?

It instigated a major shift in understanding the natural world, challenging ideas and fostering debate. (B) Signup and view all the answers

Which of the following best describes the significance of the Galápagos Islands in Darwin's evolutionary theory?

They showcased distinct, isolated ecosystems whose species had unique traits, prompting questions about species development. (D) Signup and view all the answers

In what specific way did Darwin's observations and insights challenge pre-existing scientific beliefs about the origin and diversity of life?

By suggesting that species could evolve gradually over time through natural selection, challenging the idea of special creation. (B) Signup and view all the answers

What was the primary reason Darwin decided to study at Cambridge, and how did this decision affect his later life?

He aimed to become a clergyman, but his passion for natural history ultimately shaped his scientific career. (A) Signup and view all the answers

How might Darwin's quote 'It is always advisable to perceive clearly our ignorance' relate to his scientific method and the development of the theory of evolution?

It emphasized the importance of acknowledging the limits of current knowledge, fostering continuous inquiry and refinement of scientific ideas. (D) Signup and view all the answers

What distinguishes Darwin’s explanation of evolution from earlier theories, such as those proposed by Lamarck?

Darwin proposed that evolution occurs through natural selection, whereas Lamarck suggested it happens through the inheritance of acquired traits. (B) Signup and view all the answers

What central theme from The Descent of Man does Darwin's quote underscore?

The argument that moral and social behaviors observed in humans have evolutionary roots, challenging the notion of human uniqueness. (C) Signup and view all the answers

How does Darwin utilize the comparison between the 'heroic little monkey' and the 'savage' to support his argument?

To argue that certain animals exhibit moral behaviors that surpass the actions of some humans, challenging anthropocentric views. (A) Signup and view all the answers

In the context of Darwin's broader arguments in The Descent of Man, what is the significance of deconstructing the perceived moral high ground of humanity?

To promote a more inclusive understanding of the natural world, positioning humans as part of a continuum of life with shared moral and social capacities. (B) Signup and view all the answers

What does Darwin's contrast between the monkey and the 'savage' imply about his view of civilization and human progress?

Civilization does not guarantee moral superiority; in some respects, certain animals may exhibit more commendable behavior than some humans. (C) Signup and view all the answers

Considering the historical context of The Descent of Man, how might Darwin's quote be interpreted as a challenge to prevailing social and ethical norms of Victorian society?

By questioning the uniqueness and inherent superiority of humans, particularly the civilized elite, over both animals and less civilized human societies, thus challenging the era's anthropocentric and Eurocentric biases. (B) Signup and view all the answers

Natural Selection

The process by which favorable traits are preserved and harmful traits are rejected in a species.

Injurious Variations

Traits that are harmful to the survival of an organism.