Ch2 Early evolutionary Ideas and Darwins Insight

What were Charles Darwin's two fundamental insights about the process of evolution? a) The environment selects on variation in the traits of individual organisms, and all species have descended from one or a few common ancestors. b) All species have descended from one or a few common ancestors, and populations, not individuals, evolve over time. c) The environment selects on variation in the traits of individual organisms, and organisms are in a constant struggle for existence. d) Populations, not individuals, evolve over time, and evolutionary change is connected to environmental fit.

a) The environment selects on variation in the traits of individual organisms, and all species have descended from one or a few common ancestors.

To explain how varieties were on the path to becoming new species, Charles Darwin introduced the concept of a) descent with modification. b) transformational change. c) variational changes d) pontaneous change.

a) descent with modification.

Charles Darwin's tree of life metaphor was used to describe a) how a common ancestral species has diverged into many species, with the various branches illustrating the relationships among species and groups of species. b) how each kingdom can be represented by a tree that branches as it grows, with each branch representing new lineages and species within the kingdom. c) diversity among living organisms as multiple, independent branches unrelated to each other. d) genetic variation within populations that led to diversification and, ultimately, speciation.

a) how a common ancestral species has diverged into many species, with the various branches illustrating the relationships among species and groups of species.

As opposed to uniformitarianism, the approach known as catastrophism explains that Earth's geological features are a result of a) sudden, cataclysmic, and large-scale geological events. b) processes that were slow and gradual, but vastly different from what is currently observable c) the same geological processes currently observable, which operate over very long periods of time in a slow and gradual manner. d) a combination of unknown processes, possibly as a result of supernatural forces, and known forces that have been measured and quantified.

a) sudden, cataclysmic, and large-scale geological events.

Although scientists widely accepted Charles Darwin's theory of evolution and common descent, one of the major problems proposed and discussed was how to account for complex structures and multiple, intricate parts. Why was this seen as a problem? Critics argued that natural selection operates in sudden gradual increments, so complex structures had to arise from spontaneous generation of the multiple parts required. Critics argued that complex structures and traits with multiple, intricate parts had to form from slow, gradual processes. c) Critics argued that Darwin's view of natural selection acting in gradual increments could not be responsible for forming complex structures and multiple, intricate parts because they had no value until fully formed. Critics argued that although natural selection did work to select advantageous traits, it could only work to select noncomplex traits.

C) Critics argued that Darwin's view of natural selection acting in gradual increments could not be responsible for forming complex structures and multiple, intricate parts because they had no value until fully formed. FEEDBACK: The initial rejection of Darwin's ideas on natural selection was in large part fueled by the problem of how to explain the evolution of complex structures and multiple, intricate parts. Critics argued that if natural selection was a slow process acting on small differences between individuals, what good would half an eye be? They argued that until a complex structure like an eye was fully formed, it would have no selective value and natural selection could not act.)

The Modern (evoutionary) Synthesis teaches that the concepts of evolution are compatible with the mechanisms of genetic inheritance. Which of the following is NOT part of the Modern Synthesis theory?

Changes in genes (genotype) of an individual always affect the phenotype of that individual.

Charles Darwin recognized that Thomas Malthus' argument applies to animal and plant populations as well as to human populations. Look at the figure and choose which observation Darwin made from this. a) Humans will inevitably outstrip the available resources necessary to sustain themselves and the population will diminish. b) Human and animal models of population growth have nothing in common. c) While humans have the ability to outstrip their food supply through unchecked population growth, plants and animals live in a balance with their food supply. d) The difference between the growth of a population and its size allowed by the food supply shows the possibility of selection through the struggle for existence.

D) The difference between the growth of a population and its size allowed by the food supply shows the possibility of selection through the struggle for existence. FEEDBACK: Malthus argued that the human population was geometrically increasing and thus would inevitably outstrip its food supply, which he believed to be arithmetically increasing. However, humans were not expected to diminish because of that, but rather population growth would slow. The two models have a lot in common except that Darwin believed that food supply would remain constant in the animal models and would grow arithmetically in the human population.

Spontaneous generation is the idea that complex life forms arise from non-living matter. This theory was disproved by _____.

Francesco Redi

______ is a theory that explains how the earth's major geological features were formed by massive, large scale events.

Theory of Catastrophism

______ studied fossils in sedimentary rocks and concluded that at one time the rocks had been under water

Xenophanes

Early Greek philosophers failed to exploit one of the greatest advantages of methodological naturalism, which is the ability to a) test hypotheses through observation and sometimes manipulation. b) formulate principles of science without having facts obtained through experimentation. c) formulate hypotheses without verification. d) interpret supernatural observations.

a) test hypotheses through observation and sometimes manipulation.

A population refers to

all the members of one species living in a given area at a given time

From the late Middle Ages up to the seventeenth century, the written records of the Bible provided a starting place for mathematically estimating the age of Earth. Scientists began to understand the age of Earth was far greater than calculations based on the Bible. Which of the following scientists had the most influence on Charles Darwin regarding the ancient age of Earth? Thomas Malthus Charles Lyell Georges Cuiver Alfred Russel Wallace

b FEEDBACK: Scottish geologist Charles Lyell (1797-1875) built on ideas first proposed by James Hutton (1726-1797) regarding the ancient age of Earth, yet Lyell developed a way to measure it. He explained Earth's geological features by the same geological processes currently observable, operating over very long periods of time. Lyell published Principles of Geology, Being an Attempt to Explain the Former Changes of the Earth's Surface, by Reference to Causes Now in Operation in 1830. His approach, known as uniformitarianism, had a strong influence on Darwin. Examine the different ideas regarding the age of Earth, from the Middle Ages through modern geology. Compare Lyell's scientific approach to these calculations and the uniformitarianism theory to the earlier catastrophism theory.

Which of the following examples best illustrates the concept of spontaneous generation? a) Some sea anemones spontaneously bud newly developed young from their outer skin. b) During flooding, frogs spontaneously arise from mud. c) When a dried bean is moistened and kept moist, it spontaneously transforms into a bean sprout. d) Maggots spontaneously transform in to flies.

b) During flooding, frogs spontaneously arise from mud.

The idea of spontaneous generation has existed in human thought ever since the earliest written history. Such thoughts prevailed until the seventeenth century, when an Italian physician, Francesco Redi, tested the question on whether flies spontaneously generate from spoiled meat. Which of the following statements is FALSE regarding this experiment? a) Redi's experiment demonstrated that maggots did not arise through spontaneous generation. b) After the jars were covered with a solid lid, no eggs or maggots were found in the meat. c) After the jars were covered with a mesh net, eggs and maggots were found in the meat. d) In spite of this experiment, spontaneous generation persisted as a theory for some time after.

c After the jars were covered with a mesh net, eggs and maggots were found in the meat. FEEDBACK: In 1668, Redi performed an early example of a modern experiment that addressed the following question—Are flies spontaneously generated from meat carcasses? When meat rotted, flies appeared, but when he used a solid lid and flies were not allowed to lay eggs, maggots did not appear. He observed the same result (no maggots) when using a mesh net, showing that if the flies had access to the meat and were able to lay eggs, maggots would appear. Since there was not enough understanding on where microorganisms come from (until Louis Pasteur's experiment), the concept of spontaneous generation continued to be believed in scientific circles for some time after that. Review Section 2.3 titled "The Origins and Diversity of Life." What does the term spontaneous generation mean?

If the idea of natural selection was Charles Darwin's first insight on evolution, which of the following would best describe Darwin's second insight? a) All species have descended from one or a few common ancestors, but they do not resemble one another in many respects. b) Earth changed over the years through many catastrophic events. c) All species have descended from one or a few common ancestors; species that share a recent common ancestor tend to resemble one another in many respects d) Populations tend to increase faster than the food supply.

c All species have descended from one or a few common ancestors; species that share a recent common ancestor tend to resemble one another in many respects FEEDBACK: The second of Darwin's insights centers on the common ancestry of all living things. Darwin hypothesized that all species have descended from one or a few common ancestors. Species that share a recent common ancestor tend to resemble one another in many respects precisely because they share recent common ancestry. Darwin also confirms that species originate from preexisting species. It was Thomas Malthus who proposed the idea of population growth and Georges Cuvier who advocated catastrophism.

Jean-Baptiste Lamarck hypothesized that changes acquired during the lifetime of an individual organism, as a result of adapting to its environment, are passed on to progeny. Why was this incorrect but still important? a) Acquired traits are heritable, but not part of the genetic makeup of the organisms. Lamarck's idea was important because he was the first to propose a process for evolutionary change. b) Acquired traits are not heritable, but Lamarck's idea was important because he verified Darwin's process of natural selection. c) Acquired traits are not heritable, but Lamarck's idea was important because he was the first to propose a process for evolutionary change and he connected it to environmental fit. d) Acquired traits are heritable, and Lamarck's idea was important because he proved Darwin's idea of variational evolution was incorrect.

c) Acquired traits are not heritable, but Lamarck's idea was important because he was the first to propose a process for evolutionary change and he connected it to environmental fit.

What was one of the ideas that separated Charles Darwin's On the Origin of Species as a complete, scientific explanation for evolution when compared to all other previous attempts? a) Darwin provided copious evidence that each species was completely unique. b) Darwin recognized that species can occasionally spontaneously arise. c) Darwin articulated a mechanistic explanation for change in species over time and the match between organisms and the environment. d) Darwin explained that each domain of living organisms has independent ancestry that diversified over much longer periods of time than previously recognized. (wrong)

c) Darwin articulated a mechanistic explanation for change in species over time and the match between organisms and the environment.

Charles Darwin's voyage across the Southern Hemisphere gave him an important insight to his theory that came from finding certain species and some fossils of their extinct predecessors in certain geographic regions. Which of the following was Darwin's conclusion that was essential in his theory and came from these biogeography evidences? a) The age of Earth must be much older than originally thought. b) Fossils of marine organisms could be found in the mountain regions of South America. c) Each species arises only a single time in a single place, by descent with modification from a closely related species. d) Fossils of very similar species might be found at very distant locations in the world.

c) Each species arises only a single time in a single place, by descent with modification from a closely related species. FEEDBACK: In On the Origin of Species, Darwin notes that similarities in "conditions of existence" are insufficient to explain the geographic clustering of similar, closely related species. Instead, he thought that geographic features seemed to play an important role. He noticed that adjacent species that are not separated by geographic barriers tend to be similar to one another despite major differences in climate and habitat. These geographic correlations supported Darwin's theory that each species arises only a single time in a single place, by descent with modification from a closely related species. Read the subsection titled "Common Descent and Biogeography" in Section 2.7, and think about the discoveries of numerous fossils of similar kinds of organisms throughout Darwin's journey. These geographical data were very important in building his theory.

Both Alfred Russel Wallace and Charles Darwin traveled extensively and were struck by the strong patterns they observed in the geographic distribution of nature's diversity. Which of the following observations did Wallace make? a) Similar species tended to be widely separated geographically and occupied widely different times in geologic history. (wrong answer) b) Geographic features seem to play an important role in the clustering of dissimilar, nonrelated species; these dissimilar species clustered together in time and space. c) Geographic features seem to play an important role in the clustering of similar, closely related species, and these similar species clustered together in time and space. d) Wallace observed that geographic distribution of species appeared to be random, correlating with the random nature of genetic mutation.

c) Geographic features seem to play an important role in the clustering of similar, closely related species, and these similar species clustered together in time and space.

Jean-Baptiste Lamarck was likely the first to propose a process for evolutionary change, and connected that process to environmental fit. However, he is most famous for his process being wrong. What was this process he proposed? a) Lamarck proposed that traits were inherited from the parents and that traits that were beneficial to the organism's survival were passed on to their progeny. b) Lamarck proposed that inherited traits were passed to offspring, but only those traits that were beneficial to the organism's survival were passed on to their offspring. c) Lamarck proposed that characteristics were acquired during the lifetime of an organism as a result of the organism's habits and these acquired traits were passed down to their offspring. d) Lamarck proposed that characteristics were acquired during the lifetime of an organism as a result of chance, but if the traits were beneficial to the organism's survival, they were passed down to their offspring.

c) Lamarck proposed that characteristics were acquired during the lifetime of an organism as a result of the organism's habits and these acquired traits were passed down to their offspring. FEEDBACK: Although Lamarck is primarily known for proposing the wrong process, what was important was that he actually proposed a process based on observation and he connected the traits observed in the organisms to environmental fit. With our modern understanding of genetics, we know that traits are not acquired, although environment can certainly influence phenotype.

What was one of the two primary distinctions between a "transformational" process of evolution, as described Jean-Baptiste Lamarck, and the "variational" process of evolution, as described by Charles Darwin? a) Darwin thought change was a result of differences acquired by members of a group and that the changes were acquired during the lifetime of the individuals and passed down to their offspring. Lamarck thought these differences already existed and were not acquired during the lifetime of the members of the group. b) Lamarck thought change was a result of a supernatural process acting on differences already existing in a group and those processes sorted on that existing variation. c) Lamarck thought change was a result of differences acquired by members of a group and that the changes were acquired during the lifetime of the individual and passed down to their offspring. Darwin thought those differences already existed and were not acquired during the lifetime of the members of the group. d) Darwin thought change was a result of a supernatural process acting on differences already existing in a group and those processes sorted on that variation.

c) Lamarck thought change was a result of differences acquired by members of a group and that the changes were acquired during the lifetime of the individual and passed down to their offspring. Darwin thought those differences already existed and were not acquired during the lifetime of the members of the group.

What was the primary difference in how Jean-Baptiste Lamarck and Charles Darwin explained the evolution of new species and the relationship among species? a) Lamarck viewed all species as interrelated due to common ancestry and believed that species sharing a more recent common ancestor more closely resemble each other; Darwin viewed relationships among species as linear chains, with groups independent of the other. b) Lamarck viewed lineages of species as not arising independently, but with each group related to the other; Darwin viewed all species as interrelated due to common ancestry and believed that species sharing a more recent common ancestor more closely resemble each other. c) Lamarck viewed relationships among species as linear chains, with each group independent of the other; Darwin viewed all species as interrelated due to common ancestry and believed that species sharing a more recent common ancestor more closely resemble each other. d) Lamarck and Darwin both viewed all species as having common ancestry, but Lamarck viewed each group as evolving independently while Darwin viewed groups as interrelated and having evolved from a single common ancestor.

c) Lamarck viewed relationships among species as linear chains, with each group independent of the other; Darwin viewed all species as interrelated due to common ancestry and believed that species sharing a more recent common ancestor more closely resemble each other.

How did Charles Lyell explain Earth's geological features? a) Lyell said Earth's features were a result of supernatural forces creating Earth in the same shape and form he observed and that it had not changed over time. b) Lyell said Earth's features were a result of cataclysmic events, like volcano eruptions and earthquakes, which resulted in rapid reshaping of Earth's features. c) Lyell said Earth's features were a result of the same processes currently observable, which have occurred over very long periods of time in a slow, gradual manner. d) Lyell said Earth's features were a result of the same processes currently observable, which have occurred over relatively short periods of time punctuated by periods of rapid change.

c) Lyell said Earth's features were a result of the same processes currently observable, which have occurred over very long periods of time in a slow, gradual manner.

The Scottish author __________ presented a well-developed and widely influential theory on how new species originate from existing species in his 1845 book, Vestiges of the Natural History of Creation. He also thought about populations evolving rather than individuals. Erasmus Darwin John Henslow c) Robert Chambers Charles Lyell

c) Robert Chambers FEEDBACK: This book, Vestiges of the Natural History of Creation (Chambers 1845), has had a great influence in the scientific community and represents the first comprehensive writing on the topic of evolution. Chambers highlighted two points—(1) the composition of species has changed over time, and (2) this change is slow, gradual, and unlinked to catastrophes. He also outlined his principle of progressive development, in which he hypothesized that new species arise from old species. Another aspect of his writing that often goes unnoticed was his idea that populations, and not individuals, evolve. This view is a significant aspect of modern evolutionary biology. Learn about this famous book and examine the influences of his writings on Charles Darwin and other scientists.

The primary difference(s) between the processes of natural selection and artificial selection is/are a) the mechanism for descent and modification. b) that artificial selection focuses on nonheritable traits while natural selection focuses on heritable traits. c) the selective agent and the traits being selected. d) that artificial selection focuses on creating varieties while natural selection only produces species.

c) the selective agent and the traits being selected.

The modern theory of evolution, with natural selection as the mechanism for biological change, came from which of the following thinkers? a) Charles Darwin and Patrick Matthew b) Charles Darwin and Charles Lyell c) Charles Darwin and Jean-Baptiste Lamarck d) Charles Darwin and Alfred Russel Wallace

d) Charles Darwin and Alfred Russel Wallace FEEDBACK: Darwin and Wallace independently came to the idea that evolution is driven by natural selection; however, Darwin and Wallace's theory of evolution by natural selection did not arise out of nowhere. Instead, the idea of natural selection as a process in which forms that are better suited to their environment increase in frequency in a population over time emerged from a rather broad philosophical and scientific tradition that came before it. Consider the paragraph on prior information that enables new theories, in Section 2.5 titled "Darwin's Theory." Look for the names of Charles Lyell and Alfred Russel Wallace and think about their contributions to the modern theory of evolution.

In his famous book Principles of Geology, Being an Attempt to Explain the Former Changes of the Earth's Surface, Charles Lyell stated that Earth's geological features were formed by the same currently observable processes taking place. Charles Darwin was greatly influenced by Lyell's work and proposed that the current diversity of life can also be explained by mechanisms that are in operation today, acting over very long periods of time. Why was this a critical understanding for both scientists? They both understood that past processes were different and that only currently observable processes could be tested. They both understood that geological processes and biological processes were different from one another, but were observable. They both understood that although past processes could not be scientifically tested, current processes in both geology and biology could be tested. d) They both understood that if currently observable processes acted in the same manner in the distant past, those processes could then be scientifically tested.

d) They both understood that if currently observable processes acted in the same manner in the distant past, those processes could then be scientifically tested. FEEDBACK: By understanding that geological processes were acting the same in the present as they did in the distant past, the concept of uniformitarianism, Lyell opened up a new understanding about the age of Earth. This was critical to understanding that our planet is indeed billions of years old, not just thousands of years old. Just as important was the connection Darwin made to biological processes. By realizing Earth was very old, and that currently observable biological processes occurred in the past, Darwin was able to formulate his hypothesis of evolution because he could use currently observable evidence to explain that evolutionary processes operate over a very long period of time, sufficient for the development of the diversity that was currently observable.

What is a scientific hypothesis? a) a way to describe nature b) an educated guess c) a conclusion regarding observations of the natural world d) an explanation of a phenomenon based on natural processes

d) an explanation of a phenomenon based on natural processes

the modern, or evolutionary, synthesis of Charles Darwin's theory is a result of our modern understanding of genetics. During the 1930s and 1940s, which two groups of scientists resolved their differences, ultimately resulting in the modern evolutionary synthesis? a) Mendelians and Lamarckians (wrong answer) b) Larmarckians and Darwinians c) Biometricians and Lamarckians d) Mendelians and biometricians

d? FEEDBACK: The rediscovery of Gregor Mendel's work in 1900 started our understanding about the true nature of genetic inheritance and opened the door for research to determine how natural selection could operate with material inherited as Mendel showed. This led to two groups of scientists, the Mendelians and the biometricians. The Mendelians viewed inherited traits as continuous while biometricians viewed inheritance as continuous. Significant work on inheritance and the subsequent discovery of DNA eroded the differences between these two groups as scientists came to understand that inheritance can operate in both a discrete and continuous manner.