Biology 3620-601 Chapter 2

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

Proposed explanation for a natural phenomenon. Scientists are interested in hypotheses that generate testable predictions.

hypothesis

A group of individuals of the same species that are found within a defined area and, if they are a sexual species, interbreed with one another.

population

A process of change in which the properties of a group change because every member of that group changes.

transformational process

Charles Lyell's theory that the very same geological processes that we observe today have operated over vast stretches of time and explain the geology of the past and the present.

uniformitarianism

A process of change in which the properties of an ensemble change, not because the individual elements change, but because of some sorting process. In evolutionary biology, the sorting process is natural selection.

variational process

What are Darwin's "two great laws"?

(1) Over time, natural selection makes organisms better and better suited to their environments. (2) All species have descended from one or, at most, a few common ancestors: Species that share more recent common ancestry tend to resemble one another more than do species that share more distant common ancestry.

Explain why the linear hierarchy of Aristotle's scala nature is incompatible with Darwin's phylogenetic view of biological diversity.

Darwin's theory provides an explanation for the hierarchical patterns of similarity between organisms. Aristotle's scala naturae arranges all living things on a single linear hierarchy from least to most developed. Darwin's theory replaces this with a branching pattern of common ancestry in which all currently living forms are descended from the same ultimate ancestor. In Darwin's model, we cannot place mice below humans, for example, because both species share a common ancestor and each has evolved from this ancestor for the same duration of time.

Within the context of evolutionary biology, what is the difference between transformational and variational processes?

During transformational change, a lineage changes over time because new traits acquired during the lifetime of individuals within it are passed down to the next generation. In a variational process, preexisting variation is sorted within a population, and this sorting produces the changes seen over time.

Why did the early observations of bacteria and fungi using microscopes delta the abandonment of the idea of spontaneous generations?

Early microscopes revealed bacterial colonies and fungal cells appearing seemingly out of nowhere, and scientists assumed that they must have arisen through spontaneous generation.

In the Middle Ages, what did people believe about the age of Earth? What evidence led to this conclusion?

In the Middle Ages, people believed that Earth was only a few thousand years old. The primary source of evidence for this belief in the Western world was the Bible and its purportedly historical record of events since the creation of Earth, Adam, and Eve.

How did Lyell's uniformitarianism help set the stage for Darwin's ideas on evolution by natural selection?

Lyell proposed that geological processes, for example the process of sedimentation, operate in a slow, gradual manner. Darwin, who knew Lyell's work well, proposed that the process of natural selection also usually operates in a slow, gradual manner.

What did Wallace conclude from the observation that "Every species has come into existence coincidence in both space and time with pre-existing closely allied species"?

Wallace concluded that new species must arise from previous ones.

How did the discover of fossils by the ancient Greeks help lead to the view that the world changes over time?

The discovery of fossils in mountain ranges by Greek philosophers such as Xenophanes suggested that those mountain ranges were once below water. This led the philosophers to conclude that the physical world is not unchanging and static, but constantly changing.

What do evolutionary biologists mean by the inheritance of acquired characteristics?

The inheritance of acquired characteristics is the idea that traits that are acquired during the lifetime of an organism are inherited by its offspring.

What are the two most important differences between artificial selection and natural selection?

The selective agent and the traits selected are the two most salient differences between these processes. Humans are the selective agent in artificial selection, whereas "nature"—environmental conditions—is the selective agent in natural selection. In artificial selection, breeders choose the trait being selected based on some personal interest: aesthetic, economic, and so forth. The process of natural selection selects traits that increase reproductive success and/or longevity.

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

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

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

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 biometricians b. Larmarckians and Darwinians c. Biometricians and Lamarckians d. Mendelians and Lamarckians

a

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 change d. spontaneous change.

a

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

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

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? a. Critics argued that natural selection operates in sudden gradual increments, so complex structures had to arise from spontaneous generation of the multiple parts required. b. 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. d. Critics argued that although natural selection did work to select advantageous traits, it could only work to select noncomplex traits.

c

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. 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

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

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

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. a. Erasmus Darwin b. John Henslow c. Robert Chambers d. Charles Lyell

c

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

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 Jean-Baptiste Lamarck c. Charles Darwin and Alfred Russel Wallace d. Charles Darwin and Charles Lyell

c

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

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.

c

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

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

The theory that the geology of the modern world is the result of sudden, catastrophic, large-scale events

catastrophism

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. Fossils of very similar species might be found at very distant locations in the world. d. Each species arises only a single time in a single place, by descent with modification from a closely related species.

d

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? a. Thomas Malthus b. Alfred Russel Wallace c. Georges Cuiver d. Charles Lyell

d

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. Populations tend to increase faster than the food supply. d. 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

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? a. They both understood that past processes were different and that only currently observable processes could be tested. b. They both understood that geological processes and biological processes were different from one another, but were observable. c. 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

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 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. b. 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. c. 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. d. 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

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

The collected efforts, primarily in the 1930s and 1940s, of evolutionary biologists, systematists, geneticists, paleontologists, population biologists, population geneticists, and naturalists in shaping modern evolutionary theory to show that a Darwinian view of small-scale and large-scale evolution alike is compatible with the mechanisms of genetic inheritance. Also known as the modern synthesis.

evolutionary synthesis

An experimental approach that examines evolutionary change in real time, often but not always by studying microbial populations in the laboratory.

experimental evolution

The hypothesis that traits acquired during the lifetime of an organism are passed on to its offspring. This idea was championed by Jean-Baptiste Lamarck.

inheritance of acquired characteristics

An approach in which the world is explained solely in terms of natural, rather than supernatural, phenomena and processes.

methodological naturalism

The study of organisms in their natural environments.

natural history

The hypothesis that evolutionary change occurs primarily as a result of large-scale changes.

saltationism

The now-disproved hypothesis that complex life-forms can arise, de novo, from inorganic matter.

spontaneous generation

Darwin's idea that organisms are continually in competition for resources.

struggle for existence

The scientific study of classifying organisms.

systematics