Inquizitve Questions Chapter 2

Alfred Russel Wallace

1. Alfred Russel Wallace contacted Darwin with a full report outlining a theory of evolution by means of natural selection before it was published. 2. Both men should receive credit for the founding of this theory, and some historians do argue that Wallace should be given primary credit. However, because Wallace had less evidence to support his theory, Darwin is generally recognized as the discoverer.

Correct Statements about DNA

1. DNA contains phosphate, deoxyribose sugar, and four types of nitrogen bases. 2. DNA is short for deoxyribonucleic acid. 3. The study of DNA structure has revealed new perspectives on biological relationships as well as the molecular clock that connects closely related species. 4. DNA analysis allows scientists to better understand certain diseases and disorders.

On his voyage around South America, Darwin discovered that different islands had - habitats and were home to - species.

1. Different: Darwin observed that no island was exactly the same. He also noted that physical variation existed between individuals on different islands. Furthermore, he found that individuals that lived in different habitats on the same island exhibited physical differences! 2. Difference: This discovery is what spearheaded the scientific process for Darwin. Once he observed that different islands have different habitats and different species, he was able to come up with explanatory hypotheses that led to the theory of evolution.

The first known outbreak of the Ebola virus occurred in 1976 in Sudan and Zaire (present-day Democratic Republic of the Congo), with outbreaks continuing since then. Identify the effects of the various Ebola outbreaks in West Africa.

1. In the 2002-2003 outbreak, nearly one-third of chimpanzees and gorillas in West Africa perished. Since these species are endangered, it is not possible to do medical research on them in order to create vaccines. 2. Only four confirmed cases of Ebola were found in North America. Due to new technologies and identification of the carrying genome, the outbreak was contained. 3. The Ebola virus has been mapped and vaccines have been developed. Still, scientists cannot always keep on top of the speed at which the virus mutates. The 2014-2015 strain likely mutated much faster than previous outbreaks, which is what made it so deadly. 4. Over 11,000 people died as a result of the 2014-2015 outbreak.

Which of the following is a correct assessment of the evolutionary synthesis?

1. The evolutionary synthesis does not involve integration of the field of anthropology. 2. Initially thought to be irreconcilable, Mendelian genetics and evolution by natural selection showed how variation was maintained in populations.

Which of the following are causes of evolution? Select all that apply.

1. natural selection 2. genetic drift 3. mutation 4. gene flow

Which of the following disciplines did Darwin draw information from in order to found the field of evolutionary biology and develop his theory?

1. systematics 2. paleontology 3. taxonomy 4. demography 5. geology

During which century did Charles Darwin come up with his theory?

19th century: Darwin developed his postulates during the 1800s, or the 19th century.

evolutionary biology

A specialty within the field of biology; the study of the process of change in organisms.

The different variants or forms of a single gene are known as -.

Alleles: genes can have different numbers of alleles.

James Hutton

Calculated Earth's age as millions of years (1788). Provided geologic evidence necessary for calculation time span of evolution.

Adaptation

Changes in physical structure, function, or behavior in a population of organisms that allow or enhance survival in a given environment. The key word here is change. Adaptations are the heritable changes that result in natural selection.

What did Darwin think was the primary mechanism (cause) of evolution?

Darwin deduced that natural selection was the primary mechanism of evolution. Over a number of generations, a common ancestor can adapt to different environments and different food resources and give rise to new species.

Darwin developed his theory of evolution by natural selection

Darwin's theory was based on the observations he made personally throughout his lifetime. He developed his theory independently.

Charles Darwin was the founder of which of the following fields?

Evolutionary Biology. Darwin was the founder of the field of evolutionary biology! He was the first person to make sense of why biological forms change over time.

At around 65 mya, a giant bolide collided with Earth in the area of the Yucatan Peninsula in Mexico. Match the results of the impact with the effects on plant and animal life at the time.

Gaint Tsunamis: The immediate impact would have created huge tsunamis or tidal waves, flooding and destroying life along the coasts. Cooling of Earth's Surface: The lack of sunlight would have prevented plants from carrying out photosynthesis. Without plants, herbivores would have had no food to eat. Creation of Large Dust Cloud: The lack of prey available would have led to mass extinctions as predators would not have been able to find enough food to eat.

Why didn't Darwin use Mendel's results when formulating his theory of evolution by natural selection?

Mendel's work was not well known until years after Darwin published his theory of evolution. Mendel conducted experiments on pea plants and published his work in 1865. Darwin published his theory of evolution by natural selection in 1859.

gene flow

Movement of alleles into or out of a population due to the migration of individuals to or from the population

Jean-Baptiste Lamarck

Posited characteristicis arcked via inheritance

Darwin wrote, "it at once struck me that under [specific environmental conditions] favorable variations would tend to be - and unfavorable ones to be -. The result of this would be the formation of new species."

Preserved & Destroyed: If variations unfavorable to survival in a changed environment are destroyed and new, favorable variations are preserved, then after many generations, the descendants will be so varied from their ancestors that they will be one or more new, different species.

Uniformitarianism

The theory by James Hutton expresses that processes that occurred in the geologic past are still at work the same way today and that many are still observable. This implies that we can observe geological processes happening today and use this knowledge to understand the geological record, which tells us something about the evolution of life on our planet.

Taxonomy

The classification of organisms into a system that reflects degree of relatedness.

geology

The study of Earth's physical history.

Lamarckism

The theory by Jean-Baptiste Lamarck asserts that evolution occurs when characteristics that are acquired during one's lifetime are passed on to the next generation. This theory was an important step in our understanding of evolution because it was the first major theory that asserted that living organisms arose from precursor species. However, Lamarck was not right about everything. We now know that parents do not pass the changes made during their lives (like a quickly grown longer neck) on to their offspring.

The ship on which Darwin took his voyage was called the HMS___

beagel: While aboard the HMS Beagle, Darwin made many ecological observations about plants, insects, birds, shells, and fossils that helped him form the basis of his lifetime of research.

Darwin called the units of inheritance that pass traits from parents to offspring

gemmules: Darwin knew that traits are selected for (or against) and are passed from parent to offspring. Like other scientists of his day, Darwin believed that each body part contained invisible particles called gemmules.

Which of the following ideas were widely accepted by scientists before Charles Darwin and which were unique contributions made by Charles Darwin?

unique contribution by Charles Darwin: Variation is one of the key features of populations of organisms that allow organisms to change over time. widely accepted before Charles Darwin: Earth is millions of years old. Environmental pressures cause organisms to change. Organisms can pass changes on to their offspring.

Below are statements regarding Darwin's life experiences and his theory of adaptation by natural selection.

1. It took Darwin most of his life to publically present his theory. Because of this, his audience had less time to consider and test his hypotheses before he passed away. 2. Darwin experienced earthquakes and other catastrophes during his voyage on the HMS Beagle. Because of Hutton and Lyell, he recognized that these catastrophes accumulated to create the present-day landscape and acknowledged that evolution is a long, gradual process. 3. It is unlikely that Darwin would have generated his theory of natural selection by adaptation without the experiences he gained from his time on the HMS Beagle. This voyage was extremely influential. 4. Darwin saw many fossils during his trip on the HMS Beagle. He witnessed many extinct fossil organisms that resemble ones that are alive today. This evidence strongly suggested that an earlier species had transformed into the modern species, most likely through a succession of species over time.

Which of the following are observations made by Thomas Malthus?

1. Malthus drew attention to the fact that access to food was very important. He noted that this access was limited and that survival depended on it. 2. One of Malthus's key observations was that individuals in a population compete. This allowed him to consider who survives and who does not. 3. He was the first to note that population sizes are eventually limited. After reaching this limit, populations either stay the same size or decrease over time. 4. Darwin was not the first person to note that there is variation between who survives and who does not. Survival is dependent upon the presence of key characteristics and those key characteristics do not belong to every member of a population. 5. Malthus did not study plants and animals. The observations he made were primarily about humans. Darwin was the first to apply them more widely.

How many decades did it take Charles Darwin to develop his ideas before publishing them in a book?

2: Darwin's background research began in the 1830s. It was not until 1856, two decades after his voyage around the world, that Darwin had gathered enough evidence and developed his ideas enough to begin writing his great work about evolution by means of natural selection.

A goal of evolutionary theory is to determine how gene frequencies change in - over time.

A population: Evolution is the change in gene frequency in a population over time; evolutionary theory is interested in determining how those frequencies change.

Mutation

A random change in a gene or chromosome, creating a new trait that may be advantageous, deleterious, or neutral in its effects on the organism.

Charles Darwin's famous book was called __________.

Darwin was the first person to develop a theory explaining how entirely new variations, or entirely new species, were formed. This is why he aptly titled his book On the Origin of Species.

What drove Darwin to finally publish his ideas nearly two decades after he began his background research?

Darwin's colleagues warned him that if he did not write his book soon, someone else might receive credit for the idea. This is what really pushed Darwin to make these ideas public.

True or False: Charles Darwin was the first person to understand how variation is maintained through genetics.

False: It was not until the 20th century that geneticists came to understand how variation is maintained and Darwin's theory of evolution was generally accepted.

True or False: Natural selection can affect gene frequencies by introducing new alleles to a population.

False: Natural selection cannot introduce new genetic material. It can work only on the variation that is already present.

True or False: By 1600, it was already widely accepted that fossils are the remains of past life.

False: People did not widely accept that fossils are the remains of past life until the 1700s. This shift occurred when Georges Cuvier (1769-1832) extensively compared the anatomy of fossil plants and animals found in different geologic strata, each from a different time in history. He determined that each stratum contained a unique set of fossils.

Darwin first based his observations about physical variation on differences between____.

Finches: While aboard the HMS Beagle, Darwin made many ecological observations about the different finch variations that he found on the Galapagos islands. A sample of that variation is illustrated below.

The physical remains of once-living organisms that have become mineralized by the replacement of organic with inorganic materials are called_____.

Fossils: This definition will be central to the information you acquire throughout this text. Fossilized teeth and bones, as well as trace fossils like coprolites and footprints, provide clues about what organisms looked and acted like in the past. The term "fossils" is also sometimes applied to remains that are not completely remineralized.

Thomas Malthus

Founded demography: only some will find enough food to survive (1798) Provived the concept of characteristics advantageous for survival.

Darwin called the units of inheritance that pass traits from parents to offspring ____

Gemmules: Darwin knew that traits are selected for (or against) and are passed from parent to offspring. Like other scientists of his day, Darwin believed that each body part contained invisible particles called gemmules.

adaptive radiation

The diversification of an ancestral species into new species that are adapted to diverse environmental niches. The key word here is diversification. Adaptive radiation is the product of natural selection by adaptation. Radiation (another word for branching out) refers to the movement of an ancestral group into new environments via migration or climate change, which results in variation. Out of one species branch comes multiple closely related species.

Which of the following findings by early researchers is most true according to the basic principles of modern genetics?

The mother and father contribute equally to the genetic makeup of a child. Mendel discovered that an individual's physical traits are determined equally by the inheritance of discrete units (today is known as genes) from the mother and the father.

natural selection

The process by which some organisms, with heritable features that are adapted to the environment, preferentially survive and reproduce, thereby increasing the frequency of those features in the population. The key words here are survive and reproduce. Natural selection can occur only when individuals pass their traits on to the next generation.

genetic drift

The random change in allele frequency from one generation to the next, with greater effect in small populations.

Systematics

The study and classification of living organisms to determine their evolutionary relationships with one another.

Demography

The study of a population's features and vital statistics, including birth rate, death rate, population size, and population density.

Paleontology

The study of extinct life-forms through the analysis of fossils.

Catastropism

The theory by Georges Cuvier conveys that events like volcanoes, earthquakes, and floods are responsible for geologic changes throughout Earth's history. Each stratum in the earth contains a unique set of fossils. The catastrophist point of view asserts that the fossils in each layer must have gone extinct due to some powerful catastrophe and that habitats were subsequently repopulated by different species moving in from elsewhere. We now know that past catastrophes, such as the extinction of the dinosaurs, have profoundly affected the direction of evolution, but they were not the leading factor in evolution.

Evolution of a Giraffe's Neck

This theory, also known as Lamarckism, assumes that evolution occurs when the characteristics acquired during one's lifetime are passed on to the next generation. Lamarck used the giraffe's neck as an example. He thought that a giraffe could will its neck to grow and reach food from tall trees in a short period of time. He thought that the same giraffe could pass its new, longer neck on to its offspring. This theory has been disproven and is no longer accepted today.

True or False: Darwin proposed that the frequency of advantageous characteristics increases over time.

True: Darwin hypothesized that surviving offspring have attributes that are advantageous for survival or reproduction. Because these offspring survive, the frequency of their advantageous characteristics increases in the next generation.

Carolus Linnaeus

Wrote "Systems of Nature" (1735) Presented the binomial nomenclature taxonomy of plants and animals

In Darwin's day, most people believed that the characteristics of offspring are an average of their parent's characteristics. This concept is called __________ inheritance.

blending: Darwin hypothesized that during fertilization, each parent contributed his or her "gemmules" to the potential offspring. The father's and the mother's gemmules then intermingled to form the characteristics observed in their progeny, a concept widely known as blending inheritance.