romikgosai/squad_modified huggingface dataset:
Page ii contains quotations by William Whewell and Francis Bacon on the theology of natural laws, harmonising science and religion in accordance with Isaac Newton's belief in a rational God who established a law-abiding cosmos. In the second edition, Darwin added an epigraph from Joseph Butler affirming that God could work through scientific laws as much as through miracles, in a nod to the religious concerns of his oldest friends. The Introduction establishes Darwin's credentials as a naturalist and author, then refers to John Herschel's letter suggesting that the origin of species "would be found to be a natural in contradistinction to a miraculous process":

Questions and answers:
["
Q: What was Isaac Newton's belief about God  on the theory of natural law?
A: a rational God who established a law-abiding cosmos", '
Q: Whose epigraph did Darwin add to On the Origin of Species harmonizing God with science and miracles together?
A: Joseph Butler', '
Q: Whose letter does the introduction to On the Origin of Species refer?
A: John Herschel', '
Q: In which edition of On the Origin of Species was the epigraph from Joseph Butler added?
A: the second edition']
Chapter I covers animal husbandry and plant breeding, going back to ancient Egypt. Darwin discusses contemporary opinions on the origins of different breeds under cultivation to argue that many have been produced from common ancestors by selective breeding. As an illustration of artificial selection, he describes fancy pigeon breeding, noting that "[t]he diversity of the breeds is something astonishing", yet all were descended from one species of rock pigeon. Darwin saw two distinct kinds of variation: (1) rare abrupt changes he called "sports" or "monstrosities" (example: ancon sheep with short legs), and (2) ubiquitous small differences (example: slightly shorter or longer bill of pigeons). Both types of hereditary changes can be used by breeders. However, for Darwin the small changes were most important in evolution.

Questions and answers:
['
Q: How far back does Chapter One of On the Origin of Species go in its coverage of animal and plant species?
A: ancient Egypt', '
Q: What does Darwin use to illustrate the effects of artificial selection?
A: fancy pigeon breeding', '
Q: From what does Darwin assert all pigeons are descended?
A: one species of rock pigeon', '
Q: Which evolutionary changes were the most important to Darwin?
A: the small changes']
In Chapter II, Darwin specifies that the distinction between species and varieties is arbitrary, with experts disagreeing and changing their decisions when new forms were found. He concludes that "a well-marked variety may be justly called an incipient species" and that "species are only strongly marked and permanent varieties". He argues for the ubiquity of variation in nature. Historians have noted that naturalists had long been aware that the individuals of a species differed from one another, but had generally considered such variations to be limited and unimportant deviations from the archetype of each species, that archetype being a fixed ideal in the mind of God. Darwin and Wallace made variation among individuals of the same species central to understanding the natural world.

Questions and answers:
['
Q: What does Darwin believe about the differences between species and varieties?
A: is arbitrary', '
Q: What does Darwin theorize about different species with regard to variety?
A: "species are only strongly marked and permanent varieties"', '
Q: What did Darwin and Wallace make central to understanding the natural world?
A: variation among individuals of the same species', '
Q: What did Darwin say that a "well marked variety" could be called?
A: incipient species"', '
Q: What did historians say that naturalists generally thought about the differences in variations in a species?
A: generally considered such variations to be limited and unimportant deviations from the archetype of each species']
He notes that both A. P. de Candolle and Charles Lyell had stated that all organisms are exposed to severe competition. Darwin emphasizes that he used the phrase "struggle for existence" in "a large and metaphorical sense, including dependence of one being on another"; he gives examples ranging from plants struggling against drought to plants competing for birds to eat their fruit and disseminate their seeds. He describes the struggle resulting from population growth: "It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms." He discusses checks to such increase including complex ecological interdependencies, and notes that competition is most severe between closely related forms "which fill nearly the same place in the economy of nature".

Questions and answers:
['
Q: What is the struggle that Darwin describes about population likened to?
A: doctrine of Malthus', '
Q: Within what frame of reference does Darwin use the phrase "Struggle for Existence?"
A: "a large and metaphorical sense', "
Q: What was Charles Lyell's perception of what organisms are exposed to in their struggle for survival?
A: all organisms are exposed to severe competition", '
Q: When is competition strongest in the natural world?
A: competition is most severe between closely related forms', '
Q: Why is competition so fierce between related species?
A: fill nearly the same place in the economy of nature".']
Chapter IV details natural selection under the "infinitely complex and close-fitting ... mutual relations of all organic beings to each other and to their physical conditions of life". Darwin takes as an example a country where a change in conditions led to extinction of some species, immigration of others and, where suitable variations occurred, descendants of some species became adapted to new conditions. He remarks that the artificial selection practised by animal breeders frequently produced sharp divergence in character between breeds, and suggests that natural selection might do the same, saying:

Questions and answers:
['
Q: What did Darwin say that artificial selection by animal breeders often causes?
A: sharp divergence in character between breeds,', '
Q: What did Darwin say could happen somewhere if there is a change in conditions?
A: extinction of some species', '
Q: What can happen if species immigrate to a new location?
A: descendants of some species became adapted to new conditions']
Darwin proposes sexual selection, driven by competition between males for mates, to explain sexually dimorphic features such as lion manes, deer antlers, peacock tails, bird songs, and the bright plumage of some male birds. He analysed sexual selection more fully in The Descent of Man, and Selection in Relation to Sex (1871). Natural selection was expected to work very slowly in forming new species, but given the effectiveness of artificial selection, he could "see no limit to the amount of change, to the beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection". Using a tree diagram and calculations, he indicates the "divergence of character" from original species into new species and genera. He describes branches falling off as extinction occurred, while new branches formed in "the great Tree of life ... with its ever branching and beautiful ramifications".

Questions and answers:
['
Q: What does Darwin say can explain diverse feature such as antlers on deer and bright feathers on certain male birds?
A: sexual selection, driven by competition between males for mates', "
Q: Which of Darwin's written works has more in depth information about sexual selection?
A: The Descent of Man, and Selection in Relation to Sex", '
Q: What did Darwin expect to see between species with the addition of artificial selection?
A: no limit to the amount of change, to the beauty and infinite complexity of the coadaptations between all organic beings', '
Q: What did Darwin use to illustrate the way that original species change and adapt into new ones?
A: a tree diagram and calculations']
In Darwin's time there was no agreed-upon model of heredity; in Chapter I Darwin admitted, "The laws governing inheritance are quite unknown." He accepted a version of the inheritance of acquired characteristics (which after Darwin's death came to be called Lamarckism), and Chapter V discusses what he called the effects of use and disuse; he wrote that he thought "there can be little doubt that use in our domestic animals strengthens and enlarges certain parts, and disuse diminishes them; and that such modifications are inherited", and that this also applied in nature. Darwin stated that some changes that were commonly attributed to use and disuse, such as the loss of functional wings in some island dwelling insects, might be produced by natural selection. In later editions of Origin, Darwin expanded the role attributed to the inheritance of acquired characteristics. Darwin also admitted ignorance of the source of inheritable variations, but speculated they might be produced by environmental factors. However, one thing was clear: whatever the exact nature and causes of new variations, Darwin knew from observation and experiment that breeders were able to select such variations and produce huge differences in many generations of selection. The observation that selection works in domestic animals is not destroyed by lack of understanding of the underlying hereditary mechanism.

Questions and answers:
['
Q: What is the theory that is based on acquired characteristics within a species?
A: Lamarckism', '
Q: What did Darwin learn about about the characteristics of domestic animals?
A: use in our domestic animals strengthens and enlarges certain parts, and disuse diminishes them', '
Q: What did Darwin speculate might be how inheritable variations might come about in a species?
A: environmental factors', '
Q: What did Darwin admit about acquired characteristics in chapter one of On the Origin of Species?
A: "The laws governing inheritance are quite unknown."', '
Q: What did Darwin learn about variations by observing breeders?
A: breeders were able to select such variations and produce huge differences in many generations of selection']
More detail was given in Darwin's 1868 book on The Variation of Animals and Plants under Domestication, which tried to explain heredity through his hypothesis of pangenesis. Although Darwin had privately questioned blending inheritance, he struggled with the theoretical difficulty that novel individual variations would tend to blend into a population. However, inherited variation could be seen, and Darwin's concept of selection working on a population with a range of small variations was workable. It was not until the modern evolutionary synthesis in the 1930s and 1940s that a model of heredity became completely integrated with a model of variation. This modern evolutionary synthesis had been dubbed Neo Darwinian Evolution because it encompasses Charles Darwin's theories of evolution with Gregor Mendel's theories of genetic inheritance.

Questions and answers:
['
Q: When was The Variation of Animals and Plants under Domestication by Charles Darwin published?
A: 1868', '
Q: What was the hypothesis that attempted to explain heredity?
A: hypothesis of pangenesis.', "
Q: While Darwin wasn't sure about blending inherited traits, what was his opinion about utilizing inherited variation?
A: Darwin's concept of selection working on a population with a range of small variations was workable", '
Q: When did a model of heredity begin to be integrated with that of variation?
A: in the 1930s and 1940s', '
Q: What was the modern evolutionary synthesis named?
A: Neo Darwinian Evolution']
Chapter VI begins by saying the next three chapters will address possible objections to the theory, the first being that often no intermediate forms between closely related species are found, though the theory implies such forms must have existed. As Darwin noted, "Firstly, why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms? Why is not all nature in confusion, instead of the species being, as we see them, well defined?" Darwin attributed this to the competition between different forms, combined with the small number of individuals of intermediate forms, often leading to extinction of such forms. This difficulty can be referred to as the absence or rarity of transitional varieties in habitat space.

Questions and answers:
['
Q: What is one possible objection to the theory of integrated variation?
A: often no intermediate forms between closely related species are found', "
Q: Why did Darwin wonder why all of nature isn't chaotic and random?
A: why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms?", '
Q: What did Darwin ultimately decide was the reason that nature is not a chaos of variation?
A: the competition between different forms, combined with the small number of individuals of intermediate forms, often leading to extinction of such forms.']
His answer was that in many cases animals exist with intermediate structures that are functional. He presented flying squirrels, and flying lemurs as examples of how bats might have evolved from non-flying ancestors. He discussed various simple eyes found in invertebrates, starting with nothing more than an optic nerve coated with pigment, as examples of how the vertebrate eye could have evolved. Darwin concludes: "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."

Questions and answers:
['
Q: What are some flying animals that Darwin thought might have evolved from bats?
A: flying squirrels, and flying lemurs', '
Q: What example did Darwin give of eyes evolving?
A: simple eyes found in invertebrates, starting with nothing more than an optic nerve coated with pigment', '
Q: How did Darwin justify his theory not breaking down?
A: any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.']
Chapter VII (of the first edition) addresses the evolution of instincts. His examples included two he had investigated experimentally: slave-making ants and the construction of hexagonal cells by honey bees. Darwin noted that some species of slave-making ants were more dependent on slaves than others, and he observed that many ant species will collect and store the pupae of other species as food. He thought it reasonable that species with an extreme dependency on slave workers had evolved in incremental steps. He suggested that bees that make hexagonal cells evolved in steps from bees that made round cells, under pressure from natural selection to economise wax. Darwin concluded:

Questions and answers:
['
Q: How does Darwin theorize that instincts have evolved in slave-making ants?
A: He thought it reasonable that species with an extreme dependency on slave workers had evolved in incremental steps.', '
Q: How does Darwin theorize that instincts have evolved in bees?
A: He suggested that bees that make hexagonal cells evolved in steps from bees that made round cells, under pressure from natural selection to economise wax', '
Q: What did Darwin notice specifically about slave-making ants?
A: some species of slave-making ants were more dependent on slaves than others']
Chapter VIII addresses the idea that species had special characteristics that prevented hybrids from being fertile in order to preserve separately created species. Darwin said that, far from being constant, the difficulty in producing hybrids of related species, and the viability and fertility of the hybrids, varied greatly, especially among plants. Sometimes what were widely considered to be separate species produced fertile hybrid offspring freely, and in other cases what were considered to be mere varieties of the same species could only be crossed with difficulty. Darwin concluded: "Finally, then, the facts briefly given in this chapter do not seem to me opposed to, but even rather to support the view, that there is no fundamental distinction between species and varieties."

Questions and answers:
['
Q: Why would hybrids have characteristics that keep them from being fertile?
A: in order to preserve separately created species', "
Q: What are Darwin's thoughts on producing hybrids of related species?
A: the viability and fertility of the hybrids, varied greatly, especially among plants", '
Q: What conclusion did Darwin come to after realizing that some diverse species were able to create variations easily, while other species thought to be closely related had difficulty?
A: support the view, that there is no fundamental distinction between species and varieties']
In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not have been produced by natural selection. He said some such features could have been by-products of adaptive changes to other features, and that often features seemed non-adaptive because their function was unknown, as shown by his book on Fertilisation of Orchids that explained how their elaborate structures facilitated pollination by insects. Much of the chapter responds to George Jackson Mivart's criticisms, including his claim that features such as baleen filters in whales, flatfish with both eyes on one side and the camouflage of stick insects could not have evolved through natural selection because intermediate stages would not have been adaptive. Darwin proposed scenarios for the incremental evolution of each feature.

Questions and answers:
['
Q: Why did Darwin introduce a new chapter in On the Origin of Species in the sixth edition?
A: to respond to criticisms of earlier editions', '
Q: What was one of the objections that Darwin addressed in his new chapter in On the Origin of Species?
A: that many features of organisms were not adaptive and could not have been produced by natural selection', "
Q: Which of Darwin's books featured a plant whose elaborate structure aided with fertilization by insects?
A: Fertilisation of Orchids", '
Q: Which scientist was addressed the most often in the new chapter of On the Origin of Species?
A: George Jackson Mivart', "
Q: What was Darwin's response to the claims that certain animals could not have evolved through natural selection?
A: Darwin proposed scenarios for the incremental evolution of each feature."]
Chapter IX deals with the fact that the geologic record appears to show forms of life suddenly arising, without the innumerable transitional fossils expected from gradual changes. Darwin borrowed Charles Lyell's argument in Principles of Geology that the record is extremely imperfect as fossilisation is a very rare occurrence, spread over vast periods of time; since few areas had been geologically explored, there could only be fragmentary knowledge of geological formations, and fossil collections were very poor. Evolved local varieties which migrated into a wider area would seem to be the sudden appearance of a new species. Darwin did not expect to be able to reconstruct evolutionary history, but continuing discoveries gave him well founded hope that new finds would occasionally reveal transitional forms. To show that there had been enough time for natural selection to work slowly, he again cited Principles of Geology and other observations based on sedimentation and erosion, including an estimate that erosion of The Weald had taken 300 million years. The initial appearance of entire groups of well developed organisms in the oldest fossil-bearing layers, now known as the Cambrian explosion, posed a problem. Darwin had no doubt that earlier seas had swarmed with living creatures, but stated that he had no satisfactory explanation for the lack of fossils. Fossil evidence of pre-Cambrian life has since been found, extending the history of life back for billions of years.

Questions and answers:
['
Q: Whose argument did Darwin borrow that geological record is very imperfect, because fossilization is rare?
A: Charles Lyell', '
Q: Which book written by Charles Lyell contains the argument that fossils are too rare to be used as proof of life suddenly arising?
A: Principles of Geology', '
Q: What did Darwin hope to find as he continued to explore new geologic discoveries?
A: that new finds would occasionally reveal transitional forms', '
Q: How long did Darwin estimate the erosion of the Weald to be?
A: 300 million years', '
Q: What is the name of the group of well-developed organisms that were discovered within fossil-bearing layers?
A: the Cambrian explosion']
Chapter X examines whether patterns in the fossil record are better explained by common descent and branching evolution through natural selection, than by the individual creation of fixed species. Darwin expected species to change slowly, but not at the same rate – some organisms such as Lingula were unchanged since the earliest fossils. The pace of natural selection would depend on variability and change in the environment. This distanced his theory from Lamarckian laws of inevitable progress. It has been argued that this anticipated the punctuated equilibrium hypothesis, but other scholars have preferred to emphasise Darwin's commitment to gradualism. He cited Richard Owen's findings that the earliest members of a class were a few simple and generalised species with characteristics intermediate between modern forms, and were followed by increasingly diverse and specialised forms, matching the branching of common descent from an ancestor. Patterns of extinction matched his theory, with related groups of species having a continued existence until extinction, then not reappearing. Recently extinct species were more similar to living species than those from earlier eras, and as he had seen in South America, and William Clift had shown in Australia, fossils from recent geological periods resembled species still living in the same area.

Questions and answers:
['
Q: How did Darwin expect species to change and evolve?
A: slowly, but not at the same rate', '
Q: What did Darwin believe were the key things needed for variation of species to form?
A: variability and change in the environment', '
Q: Which scientist theorized that the earliest members of a class in a species were simple and generalized?
A: Richard Owen', '
Q: What did Darwin discover about more recently extinct species?
A: Recently extinct species were more similar to living species than those from earlier eras']