Why don’t we see animals with wheels as body parts in nature?

Because a structure capable of rolling continuously around an axle would be physically separated from the body and impossible to build in a developing animal.

Because wheels are not biologically possible

Because wheels are not efficient for movement

Because animals prefer walking with their legs

Why can't humans evolve wings like birds or bats?

Because each stage of a trait's evolution must provide an advantage, so evolving wings would require multiple beneficial intermediate steps which is unlikely.

Because mutations in Hox genes prevent wing development

Because humans are not capable of flight

Because wings would hinder the use of tools

What is the reason behind not seeing animals with laser turrets in nature?

Intermediate steps in evolution must be helpful or at least not harmful, so incomplete laser organs would be functionless and a fitness loss.

Because laser turrets are unnecessary for animal survival

Because animals don't have the intelligence to create laser turrets

Because there is no need for animals to defend themselves with weapons

Why do large land animals not exist beyond a certain weight limit?

Due to the square-cube law, as an organism grows bigger, its volume increases faster than its surface area, making processes dependent on surface area less efficient.

Because food sources for large land animals are scarce

Because large land animals would be unable to move effectively

Because large land animals are unable to support their own weight

Why have certain impossible phenotypes like freshwater coral reefs or plant-eating snakes not evolved in nature?

Selection pressures and environmental factors play a role in determining adaptations, and sometimes there may not be a need or advantage for certain traits to evolve.

Because evolution is a slow process

Because plants do not offer sufficient nutrients for snakes

Because certain animals are already well adapted to their environments

What is an example of a local optimum in evolution?

The human eye is a local optimum because rearranging the optic nerve and blood vessels for better vision would require moving through a fitness valley of worse vision temporarily.

The arrangement of internal organs

The bony structure of the spine

Why do camels outperform wheeled vehicles in certain regions for transportation?

Camels are more efficient due to their ability to travel long distances with less food and water, navigate rough terrain, and require less manpower to manage compared to wheeled vehicles.

Because camels can carry heavier loads than wheeled vehicles

Because camels have higher speeds than wheeled vehicles

Because wheeled vehicles are more stable than camels

Why do certain adaptations or traits not evolve in animals despite their potential benefits?

Intermediate steps in evolution must be beneficial or at least not harmful, so traits like defensive laser weapons cannot evolve if incomplete versions are non-functional and costly.

Because certain traits are unnecessary for animal survival

Because animals lack the genetic capacity for complex adaptations

Because adaptations must have immediate advantages to evolve

How do physical limitations like gravity and the square-cube law influence the evolution of land animals?

Physical constraints like gravity and the square-cube law limit the size and shape of land animals due to efficiency issues related to volume increase outpacing surface area growth.

Physical laws allow land animals to adapt easily to different environments

Physical limitations encourage the evolution of larger land animals

Physical constraints promote diverse body shapes in land animals

Why are certain impossible phenotypes like freshwater coral reefs or plant-eating snakes not observed in nature?

Selection pressures and environmental factors influence the evolution of traits, and sometimes there may not be a need or advantage for certain adaptations like plant-eating snakes to arise.

Because evolution lacks creativity to produce diverse phenotypes

Because certain traits are biologically unattainable

Because animals are resistant to changing their diets

What is the function of the larger spleens in Bajau divers?

Store more red blood cells carrying oxygen

Evolution Video Questions

Human forced Evolution Video Question

Continental Drift Theory. From the discussion of the rock cycle, it has been pointed out that through Earth's external and internal processes. Earth's surface is constantly changing. However, this idea of a changing environment did not conform with the belief of earlier scientists. Rather, they thought that the geographic positions of ocean basins and continents have been static since the beginning of time. It was around the 1500s when Leonardo da Vinci, upon his discovery of fossil seashells found at the high mountains of Italy, first thought of the idea that the areas where mountains are located may have been oceans in the past. Through time, other fossils of marine organisms found far above the current sea level further supported the idea that mountains were uplifted and weathering wore them down. At around the 1800s, most scientists have accepted the idea that Earth's crust is undergoing large vertical movements or uplifting. There was also evidence of possible horizontal movements, but the scientists then were not convinced about it. Alfred Wegener showed evidence of horizontal or lateral movement of the continents in his continental drift theory. According to him, the continents have drifted around the world and have once formed a giant landmass or supercontinent called Pangaea. To support his theory, Alfred Wegener presented a set of geographical, biological, and climatic evidence.Wegener's geographical evidence included the jigsaw puzzle fit of the current continents. He pointed out that the coastlines of South America and Africa seem to fit together. He also pointed the presence of mountain ranges having similar rock types and age but separated by vast oceans, like that of the folded rocks of the Caledonian mountains. The same folded rocks run through West Africa, North America, Newfoundland, Ireland, Wales, Scotland, Greenland, and Norway, all of which are now separated by the Atlantic Ocean. A geographical evidence on the similar rock types in West Africa, North America, Greenland, and Europe is found. The biological evidence came in the discovery of similar plant and animal fossils in different continents separated by oceans. The animal fossils of Mesosaurus and Lystrosaurus indicate that they were not capable of crossing the oceans to reach the other continents. If they were, the fossils should have been more widely distributed Africa, Australia, India, and South America were too large to be carried by wind. This indicates that the areas where the fossils were found were closely linked. It has also been found out that the plant only grew in areas with subpolar climate, which would indicate that the landmasses were located near the South Pole.Lastly, for his climatic evidence, Wegener discovered that a glacial period occurred during the late Paleozoic era in Southern Africa, South America, Australia, and India. The initial explanation for this event was global cooling, but it was rejected because large tropical swamps with so much vegetation were found at the same time in the Northern Hemisphere. This further supported the idea that the supercontinent was indeed near the South Pole, and the continents in Northern Hemisphere were once near the equator. The glacial period also left glacial striations, or the scratches glaciers make as they move across on the underlying bedrock, on the aforementioned continents. For such an event to happen, the continents would have to be connected. SCIENCE PIONEER. Alfred Wegener (1880-1930). Alfred Wegener was a German polar researcher, geophysicist, and meteorologist. He was known for his work on the continental drift theory. In his effort to defend his work, he went to the Greenland ice sheet where he died.Even with all the compelling evidence, the continental drift theory hardly convinced the scientific community at that time because Wegener was unable to identify a credible mechanism that drives the continental drift. He was unable to clearly explain how the continents moved and how the larger continents broke through the ocean floor. Eventually, critics of the continental drift began to accept the theory when new evidence supporting the theory was discovered. The new evidence led to a more encompassing theory the theory of plate tectonics. This theory provided a more convincing explanation as to how the continents moved. The evidence that paved the way for the theory of plate tectonics was the idea of wandering poles. Scientists began studying volcanic rocks to determine the location of the magnetic poles. When volcanic rocks crystallize, the minerals with magnetic properties align themselves parallel to Earth's magnetic field at the time the minerals were formed. This finding allowed scientists to determine the polarity of Earth's magnetic field and the magnetic inclination that showed the location of the poles. Upon studying the paleomagnetism of the rocks, geophysicists found out that rocks from various locations point to different magnetic north poles, suggesting that the poles have wandered. Since movement of magnetic poles is very unlikely, scientists have accepted the idea that the continents are indeed moving. And if the continents are moving, scientists thought that maybe the ocean basins are moving too. They also discovered that some rocks showed magnetic reversals, which led them to believe that the magnetic north pole now was not always the magnetic north pole. Seafloor Spreading. After World War II, exploration on the ocean floor became the focus of many geologic studies. It was only then that the ocean ridge system was discovered. A geologist in Princeton University named Harry Hess, along with other scientists, studied this ocean ridge system and hypothesized that the oceanic crust was moving away from the ridge. His hypothesis, known as seafloor spreading, showed that the ocean floor is split along the ridge where the magma rises to form the new ocean floor.Because of this, rocks located near the ridge are younger than those that are located magnetic polarity of Earth is also preserved in those rocks. Withe ridge scientists were able to see the magnetic reversals in the ocean floor, and they were able to make use of information to determine that the ocean floor is moving at a rate of about 10 cm per year. Plate Tectonics. Confirmation of the seafloor spreading hypothesis proved that continents are not moving above the ocean floor. Rather, it is the fragments of the lithosphere. The lithosphere is the rigid layer that is composed of the uppermost mantle and the crust that carry the continents and the ocean basins along. These fragments of the lithosphere are called plates. Underneath the lithosphere is a weaker region in the mantle known as asthenosphere that behaves like a fluid. Thus, the lithosphere floats above the asthenosphere, making it detached and free to move. This became the basis of the theory of plate tectonics. Now that it has been made clear that it is the plates which are moving, the question as to how they move remained. Sir Arthur Holmes proposed the driving force for this plate movement in 1919. He suggested that the movement in the mantle carries the plates along. It was previously discussed that Earth's interior is very hot due to the heat produced by radioactive decay. Convection takes place in the mantle, keeping the asthenosphere hot and weak. The convection currents produced in the asthenosphere are the ones carrying the lithospheric plates and making them move. However, convection currents are not enough. Mechanisms such as ridge push and slab pull aid the convection currents to slowly move the lithospheric plates. Ridge push occurs at mid ocean ridges which are higher in elevation than the surrounding trenches and abyssal plains. The new ocean floor from the ridge is hot and relatively thin. As it moves away from the ridge, it cools down and gets denser, heavier, and thicker. Below this cooling ocean floor is the asthenosphere, which is less dense. This area becomes a massive shear zone and the new ocean floor will effectively slide down the slope of the asthenosphere. When the plate collides with another plate with lesser density, the denser plate sinks and a subduction zone is formed. When the subducting plate sinks, it pulls on the rest of the plate behind it. These mechanisms explain the movement of the plates.Earth has seven major lithospheric plates that account for 94% of Earth's surface. These are the North American Plate, South American Plate, Pacific Plate, African Plate, Eurasian Plate, Indo-Australian Plate, and Antarctic Plate. These plates are constantly moving relative to the other plates. Thus, the interaction of plates occurs mostly along the boundaries. These movements are plotted using information from earthquakes and volcanic activities. There are three main types of plate boundaries: convergent, divergent, and transform boundaries Convergent boundaries are boundaries where two plates move towards each other A convergent boundary is also known as destructive margin since this is where the collision between two plates occhins. There are three types of convergence-oceanic oceanic, oceanic-continental, and continental-continental. Trenches are features of the ocean floor that are present in both oceanic-oceanic boundary and oceanic-continental boundary. Subduction occurs at the trenches, therefore, these are characterized as the deepest parts of Earth. A divergent boundary is the opposite of convergent boundary: two plates move away from each other. Divergent boundaries create new crust; thus, they are also known as constructive margins. The ocean ridge system is a divergent boundary where new ocean floor is produced as magma rises, pushing the older rocks aside.Transform boundary is also known as conservative plate margin since two plates just move past one another, neither creating nor destroying land. Earthquake epicenters are usually detected at transform boundaries because the rocks tend to break and not fold or sink, like in convergent boundaries. Evolution of the Ocean Basins. Both the movement of the plates and seafloor are responsible for the evolution of ocean basins. Along the divergent boundary where ocean ridge systems are found, magma is released and new ocean floor is created. Along convergent boundaries, the ocean floor is being destroyed. The evolution of the ocean basins started during the time when Pangaea was still present and was surrounded by the vast ocean or superocean known as Panthalassa, also called Paleo-Pacific or "old Pacific." Upon the initial break up of Pangaea into Laurasia and Gondwanaland, the Tethys Sea began to form. Then, the Eurasian and North about, forming the North Atlantic. The South Atlantic only started to form when the African Plate and South American Plate separated. The continued movement of the plates created the Himalayas at one side and separated the Pacific Ocean and Atlantic Ocean at the other side, which consequently formed the current ocean basins. Both the movement of the plates and seafloor are responsible for the evolution of ocean basins. Along the divergent boundary where ocean ridge systems are found, magma is released and new ocean floor is created. Along convergent boundaries, the ocean floor is being destroyed. The evolution of the ocean basins started during the time when Pangaea was still present and was surrounded by the vast ocean or superocean known as Panthalassa, also called Paleo-Pacific or "old Pacific." Upon the initial break up of Pangaea into Laurasia and Gondwanaland, the Tethys Sea began to form. Then, the Eurasian and North about, forming the North Atlantic. The South Atlantic only started to form when the African Plate and South American Plate separated. The continued movement of the plates created the Himalayas at one side and separated the Pacific Ocean and Atlantic Ocean at the other side, which consequently formed the current ocean basins.Continents do not immediately end at the point where the ocean meets the land. They may extend slightly into the oceans. The portion of the continent that is submerged is called continental margin. There are two types of continental margin: passive margin and active margin. A passive continental margin consists of a continental shelf, continental slope, and continental rise. It is not associated with plate boundaries; thus, there are very little tectonic activities. An active continental margin only has a continental shelf and a continental slope. It is associated with plate boundaries; thus, a main feature of this boundary is a trench. The different features of a continental margin are the following: 1. The continental shelf is the gently-sloping submerged portion of the continent. 2. The continental slope is the steep slope after the continental shelf. It is still part of the continent. 3. The continental rise is the gently-sloping area after the continental slope and before the ocean floor. 4. The trenches are the deepest parts of the ocean. These are narrow depressions caused by the subduction of the ocean floor along the convergent boundaries. 5. The mid-oceanic ridge is the mountain range system in the ocean. It is responsible for the production of new ocean floor. This is the region where new magma constantly emerges from. SCIENCE CAREER. A scientific illustrator uses art to inform and communicate complex details and concepts of science. He/She makes use of scientifically informed observations and research along with his/her technical art and aesthetic skills to make accurate representations. In Natural History, the scientific illustrators recreate how the extinct species look like by working with scientists and fossil records. Moreover, with the advances in technology, illustrators are now into 3D modelling, animation, and video making. Earth's History. All the processes that have been discussed require long periods of time to create a noticeable change on Earth's surface. You can just imagine how long it would take to create an oceanas vast as the Pacific Ocean if the ocean floor moves only at about 10 cm/year. It is then important to know the history of Earth to learn the complexities of its past and be able to use it to understand the present. Just like learning the history of a country that requires one to read a lot of books, learning the history of Earth involves studying a lot of rocks. Rocks, especially sedimentary rocks, contain a lot of information about Earth's past. It holds the key to most of the geologic processes that happened on Earth and the key to uncovering how life on Earth evolved. But these discoveries are worthless if there is no time perspective. Thus, one of the most important contributions of geologists to mankind is the geologic time scale, which holds a history that is exceedingly long.

Good day this is Chris today we will be doing a quick walkthrough on ISO 14001 2015 Environmental Management System and its main clauses let's get started ISO 14001 2015 Environmental Management System is a globally recognized standard for environment Management systems or EMS an EMS is a framework that organizations use to manage their environmental impact comply with regulations and improve their environmental performance the standard outlines are requirements for an EMS including the development of an environmental policy the identification of environmental aspects and impacts the establishment of objectives and targets the implementation of operational control monitoring and measurement systems and the ongoing review and Improvement of the system ISO 14001 is a flexible standard that can be used by organizations of any size or type regardless of their environment impact or level of environment performance it provides a practical framework for organizations to manage their environmental impact reduce environment risks and demonstrate their commitment on sustainability to their stakeholders here is the standard that provides a structured approach to develop an EMS which includes several key steps one organizations must develop an environmental policy that outlines their commitment to environmental sustainability this policy should be communicated to all employees and stakeholders two organizations must identify their environmental aspects and impacts this involves identifying the activities products and services that have an impact on the environment as well as the potential environmental consequences of those impacts three once the environmental aspects and the impacts have been identified organizations must establish environmental objectives and targets these objectives and targets should be specific measurable achievable relevant and time-bound 4. after setting objectives and targets organizations must Implement operational controls and establish monitoring and measurement systems to ensure that they are meeting their objectives and targets finally organizations must review and continually improve their EMS this involves conducting regular audits reviewing the EMS to ensure that it remains relevant and effective and making any necessary changes or improvements the main Clause of iso 14001 2015 apart from its scope normative references and terms and conditions that the main Clauses of iso 14001 2015 can be listed as context of the organization leadership planning support operation performance evaluation and Improvement Clause 4.0 context of the organization is about understanding the organization and its context understanding the needs and expectations of the interested parties determining the scope of the Environmental Management System EMS and Environmental Management System itself Clause 5.0 talks about leadership and commitment Environmental Policy organizational roles responsibility and authorities Clause 6.0 planning focuses on actions to address risk and opportunities as well as environmental objectives and planning to achieve them Clause 7.0 support are detailed requirements on resources competence awareness communication that includes external and internal communication documented information that involves creating updating in control of documented information Clause 8.0 operation talks about operational planning and control as well as emergency preparedness and response overall the design of iso 14001 2015 provides guidelines to form a system that is structured to cater the requirements of stakeholder needs and expectations to drive life cycle perspective and Energy Efficiency as pictured here Clause 9.0 performance evaluation provides guidelines to monitoring measurement analysis and evaluation evaluation compliance and management review an additional note here is that ISO 19011 2018 guidelines for auditing Management Systems which is an audit process that will determine the scope to establish the audit criteria by collecting evidence evaluating the evidence and then draw a conclusion based on the findings as pictured here [Music] finally Clause 10.0 Improvement talks about how Improvement is an integral factor to an effective Environmental Management system through General non-conformity and corrective action and continual Improvement talking about Improvement it is always continual in putting efforts towards the betterment of the existing system here is a snapshot of the main Clauses of iso 14001 2015 [Music] I hope you find this video useful we are industry experts specialized in management system consultancy and Industry relevant corporate training give us a call and let us help you drive your business excellence and upskill your employees to elevate workplace efficiency [Music] CREATE 10 MCQ AND 2 SAQ QUESTIONS BASED ON THE ABOVE PARAGRAPH

Hi, I'm John Green, this is Crash Course U.S. History, and today, we're going to talk about slavery, which is not funny. 0:06 Yeah, so we put a lei on the eagle to try and cheer you up, but let's face it, this is going to be depressing. 0:10 With slavery, every time you think, like, "Aw, it couldn't have been that bad," it turns out to have been much worse. 0:14 Mr. Green, Mr. Green! But what about – 0:15 Yeah, Me from the Past, I'm going to stop you right there, because you're going to embarrass yourself. Slavery was hugely important to America. 0:20 I mean, it led to a civil war and it also lasted what, at least in U.S. history, counts as a long-ass time, from 1619 to 1865. 0:29 And yes, I know there's a 1200-year-old church in your neighborhood in Denmark, but we're not talking about Denmark! 0:35 But slavery is most important because we still struggle with its legacy. 0:38 So, yes, today's episode will probably not be funny, but it will be important. 0:42 [Theme Music] North & South economic ties 0:51 So the slave-based economy in the South is sometimes characterized as having been separate from the Market Revolution, but that's not really the case. 0:57 Without southern cotton, the North wouldn't have been able to industrialize, at least not as quickly, because cotton textiles were one of the first industrially products. 1:04 And the most important commodity in world trade by the nineteenth century, and 3/4 of the world's cotton came from the American South. 1:11 And speaking of cotton, why has no one mentioned to me that my collar has been half popped this entire episode, like I'm trying to recreate the Flying Nun's hat. 1:18 And although there were increasingly fewer slaves in the North as northern states outlawed slavery, cotton shipments overseas made northern merchants rich. 1:26 Northern bankers financed the purchase of land for plantations. 1:29 Northern insurance companies insured slaves who were, after all, considered property, and very valuable property. 1:35 And in addition to turning cotton into cloth for sale overseas, northern manufacturers sold cloth back to the South, where it was used to clothe the very slaves who had cultivated it. 1:45 But certainly the most prominent effects of the slave-based economy were seen in the South. Slave-based agriculture in the South 1:49 The profitability of slaved-based agriculture, especially King Cotton, meant that the South would remain largely agricultural and rural. 1:56 Slave states were home to a few cities, like St. Louis and Baltimore, but with the exception of New Orleans, 2:00 almost all southern urbanization took place in the upper South, further away from the large cotton plantations. 2:06 And slave-based agriculture was so profitable that it siphoned money away from other economic endeavors. 2:11 Like, there was very little industry in the South. 2:13 It produced only 10% of the nation's manufactured goods. 2:16 And, as most of the capital was being plowed into the purchase of slaves, there was very little room for technological innovation, like, for instance, railroads. 2:23 This lack of industry and railroads would eventually make the South suck at the Civil War, thankfully. 2:27 In short, slavery dominated the South, shaping it both economically and culturally, and slavery wasn't a minor aspect of American society. Popular attitudes concerning slavery 2:35 By 1860, there were four million slaves in the U.S., and in the South, they made up one third of the total population. 2:42 Although in the popular imagination, most plantations were these sprawling affairs with hundreds of slaves, 2:47 in reality, the majority of slaveholders owned five or fewer slaves. 2:51 And, of course, most white people in the South owned no slaves at all, though, if they could afford to, they would sometimes rent slaves to help with their work. 2:57 These were the so-called yeoman farmers who lived self-sufficiently, raised their own food, and purchased very little in the Market Economy. 3:04 They worked the poorest land and, as a result, were mostly pretty poor themselves. 3:08 But even they largely supported slavery, partly, perhaps, for aspirational reasons, and partly because the racism inherent to the system gave even the poorest whites legal and social status. 3:18 And southern intellectuals worked hard to encourage these ideas of white solidarity and to make the case for slavery. 3:23 Many of the founders, a bunch of whom you'll remember, held slaves, saw slavery as a necessary evil. 3:29 Jefferson once wrote, quote, "As it is, we have the wolf by the ear, and we can neither hold him, nor safely let him go. 3:37 Justice is on one scale, and self-preservation in the other." 3:41 The belief that justice and self-preservation couldn't sit on the same side of the scale was really opposed to the American idea, 3:47 and, in the end, it would make the Civil War inevitable. 3:50 But as slavery became more entrenched in these ideas of liberty and political equality were embraced by more people, 3:55 some southerners began to make the case that slavery wasn't just a necessary evil. 3:59 They argued, for instance, that slaves benefited from slavery. 4:03 Because, you know, because their masters fed them and clothed them and took care of them in their old age. 4:07 You still hear this argument today, astonishingly. 4:09 In fact, you'll probably see asshats in the comments saying that in the comments. 4:12 I will remind you, it's not cursing if you are referring to an actual ass. 4:15 This paternalism allowed masters to see themselves as benevolent and to contrast their family-oriented slavery with the cold, mercenary Capitalism of the free-labor North. 4:26 So yeah, in the face of rising criticism of slavery, some southerners began to argue that the institution was actually good for the social order. 4:33 One of the best-known proponents of this view was John C. Calhoun, who, in 1837, said this in a speech on the Senate floor: 4:40 "I hold that, in the present state of civilization, 4:43 where two races of different origin and distinguished by color and other physical differences as well as intellectual, are brought together, 4:51 the relation now existing in the slave-holding states between the two is, instead of an evil, a good. A positive good." 4:59 Now, of course, John C. Calhoun was a fringe politician, and nobody took his views particularly seriously. 5:04 Stan: Well, he was Secretary of State from 1844 to 1845. 5:07 John: Well, I mean, who really cares about the Secretary of State, Stan? 5:10 Danica: Eh, he was also Secretary of War from 1817 to 1825. 5:13 John: All right, but we don't even have a Secretary of War anymore, so... 5:16 Meredith: And he was Vice President from 1825 to 1832. 5:19 John: Oh my god, were we insane?! 5:21 We were, of course, but we justified the insanity with Biblical passages and with the examples of the Greeks and Romans, 5:28 and with outright racism, arguing that black people were inherently inferior to whites. 5:33 And that not to keep them in slavery would upset the natural order of things. 5:37 A worldview popularized millennia ago by my nemesis, Aristotle. God, I hate Aristotle. 5:42 You know what defenders of Aristotle always say? 5:44 "He was the first person to identify dolphins." 5:47 Well, ok, dolphin identifier. 5:50 Yes, that is what he should be remembered for, but he's a terrible philosopher! Lives & experiences of enslaved people 5:53 Here's the truth about slavery: 5:55 It was coerced labor that relied upon intimidation and brutality and dehumanization. 6:00 And this wasn't just a cultural system, it was a legal one. 6:03 I mean, Louisiana law proclaimed that a slave "owes his master... a respect without bounds, and an absolute obedience." 6:09 The signal feature of slaves' lives was work. 6:12 I mean, conditions and tasks varied, but all slaves labored, usually from sunup to sundown, and almost always without any pay. 6:20 Most slaves worked in agriculture on plantations, and conditions were different, depending on which crops are grown. 6:25 Like, slaves on the rice plantations of South Carolina had terrible working conditions, 6:29 but they labored under the task system, which meant that once they had completed their allotted daily work, they would have time to do other things. 6:36 But lest you imagine this is like how we have work and leisure time, bear in mind that they were owned and treated as property. 6:42 On cotton plantations, most slaves worked in gangs, usually under the control of an overseer, or another slave who was called a "driver." 6:49 This was back-breaking work done in the southern sun and humidity, and so it's not surprising that whippings – or the threat of them – were often necessary to get slaves to work. 6:58 It's easy enough to talk about the brutality of slave discipline, but it can be difficult to internalize it. 7:03 Like, you look at these pictures, but because you've seen them over and over again, they don't have the power they once might have. 7:09 The pictures can tell a story about cruelty, but they don't necessarily communicate how arbitrary it all was. 7:14 As, for example, in this story, told by a woman who was a slave as a young girl: 7:18 "[The] overseer... went to my father one morning and said, "Bob, I'm gonna whip you this morning." 7:22 Daddy said, "I ain't done nothing," and he said, "I know it, I'm going to whip you to keep you from doing nothing," 7:28 and he hit him with that cowhide – you know it would cut the blood out of you with every lick if they hit you hard." 7:33 That brutality – the whippings, the brandings, the rape – was real, and it was intentional, because, in order for slavery to function, slaves had to be dehumanized. 7:43 This enabled slaveholders to rationalize what they were doing, and it was hoped to reduce slaves to the animal property that is implied by the term "chattel slavery." 7:51 So the idea was that slaveholders wouldn't think of their slaves as human, and slaves wouldn't think of themselves as human. 7:57 But it didn't work. Let's go to the Thought Bubble. 7:59 Slaves' resistance to their dehumanization took many forms, but the primary way was by forming families. Family, love, & religion of enslaved people 8:05 Family was a refuge for slaves and a source of dignity that masters recognized and sought to stifle. 8:10 A paternalistic slave owner named Bennet H. Barrow wrote in his rules for the Highland Plantation: 8:15 "No rule that I have stated is of more importance than that relating to Negroes marrying outside of the plantation... It creates a feeling of independence." 8:23 Most slaves did marry, usually for life, and, when possible, slaves grew up in two-parent households. 8:28 Single-parent households were common, though, as a result of one parent being sold. 8:32 In the upper South, where the economy was shifting from tobacco to different, less labor-intensive cash crops, the sale of slaves was common. 8:40 Perhaps one-third of slave marriages in states like Virginia were broken up by sale. 8:45 Religion was also an important part of life in slavery. 8:47 While masters wanted their slaves to learn the parts of the Bible that talked about being happy in bondage, 8:52 slave worship tended to focus on the stories of Exodus, where Moses brought the slaves out of bondage, 8:57 or Biblical heroes, who overcame great odds, like Daniel and David. 9:01 And, although most slaves were forbidden to learn to read and write, many did anyway. And some became preachers. 9:07 Slave preachers were often very charismatic leaders, and they roused the suspicion of slave owners, and not without reason. 9:13 Two of the most important slave uprisings in the South were led by preachers. 9:16 Thanks, Thought Bubble. 9:17 Oh, it's time for the Mystery Document? Mystery Document 9:19 We're doing two set pieces in a row? All right. [buzzing noise] [music] 9:24 The rules here are simple. 9:26 I wanted to re-shoot that, but Stan said no. 9:29 I guess the author of the Mystery Document. 9:30 If I am wrong, I get shocked with the shock pen. 9:33 "Since I have been in the Queen's dominions I have been well contented, yes well contented for sure, man is as God intended he should be. 9:40 That is, all are born free and equal. 9:43 This is a wholesome law, not like the southern laws which puts man made in the image of God on level with brutes. 9:49 O, what will become of the people, and where will they stand in the day of judgment. 9:53 Would that the 5th verse of the 3rd chapter of Malachi were written as with a bar of iron, 9:59 and the point of a diamond upon every oppressor's heart that they might repent of this evil, and let the oppressed go free..." 10:06 All right, it's definitely a preacher, because only preachers have read Malachi. 10:10 Probably African American, probably not someone from the South. 10:13 I'm going to guess that it is Richard Allen, the founder of the African Methodist Episcopal Church? 10:18 [buzzing noise] DAAAH, DANG IT! 10:19 It's Joseph Taper, and Stan just pointed out to me that I should have known it was Joseph Taper because it starts out, 10:24 "Since I have been in the Queen's dominions..." 10:27 He was in Canada. He escaped slavery to Canada. The Queen's dominions! 10:31 All right, Canadians, I blame you for this, although, thank you for abolishing slavery decades before we did. 10:36 [electric sounds] AHHH! How people resisted & escaped slavery 10:37 So, the Mystery Document shows one of the primary ways that slaves resisted their oppression: by running away. 10:42 Although some slaves like Joseph Taper escaped for good by running away to northern free states, 10:47 or even to Canada, where they wouldn't have to worry about fugitive slave laws, even more slaves ran away temporarily, hiding out in the woods or the swamps, and eventually returning. 10:55 No one knows exactly how many slaves escaped to freedom, but the best estimate is that a thousand or so a year made the journey northward. 11:01 Most fugitive slaves were young men, but the most famous runaway has been hanging out behind me all day long: Harriet Tubman. 11:07 Harriet Tubman escaped to Philadelphia at the age of 29, and over the course of her life, she made about 20 trips back to Maryland to help friends and relatives make the journey north on the Underground Railroad. 11:17 But a more dramatic form of resistance to slavery was actual, armed rebellion, which was attempted. 11:22 Now, individuals sometimes took matters into their own hands and beat or even killed their white overseers or masters. 11:27 Like Bob, the guy who received the arbitrary beating, responded to it by killing his overseer with a hoe. 11:33 But that said, large-scale slave uprisings were relatively rare. 11:36 The four most famous ones all took place in a 35-year period at the beginning of the 19th century. Slave rebellions 11:41 Gabriel's Rebellion in 1800 – which we've talked about before – was discovered before he was able to carry out his plot. 11:45 Then, in 1811, a group of slaves upriver from New Orleans seized cane, knives, and guns, and marched on the city before militia stopped them. 11:52 And in 1822, Denmark Vesey, a former slave who had purchased his freedom, may have organized a plot to destroy Charleston, South Carolina. 11:59 I say "may have" because the evidence against him is disputed and comes from a trial that was not fair. 12:05 But regardless, the end result of that trial was that he was executed, as were 34 slaves. Nat Turner's Rebellion 12:09 But the most successful slave rebellion, at least in the sense that they actually killed some people, was Nat Turner's in August 1831. 12:15 Turner was a preacher, and with a group of about 80 slaves, he marched from farm to farm in South Hampton County, Virginia, 12:21 killing the inhabitants, most of whom were women and children, because the men were attending a religious revival meeting in North Carolina. 12:27 Turner and 17 other rebels were captured and executed, but not before they struck terror into the hearts of whites all across the American South. 12:34 Virginia's response was to make slavery worse, passing even harsher laws that forbade slaves from preaching, and prohibited teaching them to read. 12:42 Other slave states followed Virginia's lead and, by the 1830s, slavery had grown, if anything, more harsh. 12:47 So, this shows that large-scaled armed resistance was – Django Unchained aside – not just suicidal, but also a threat to loved ones and, really, to all slaves. How enslaved people resisted their oppression & why it matters 12:55 But, it is hugely important to emphasize that slaves did resist their oppression. 12:59 Sometimes this meant taking up arms, but usually it meant more subtle forms of resistance, 13:03 like intentional work slowdowns or sabotaging equipment, or pretending not to understand instructions. 13:08 And, most importantly, in the face of systematic legal and cultural degradation, they re-affirmed their humanity through family and through faith. 13:16 Why is this so important? 13:17 Because too often in America, we still talk about slaves as if they failed to rise up, 13:21 when, in fact, rising up would not have made life better for them or for their families. 13:26 The truth is, sometimes carving out an identity as a human being in a social order that is constantly seeking to dehumanize you, is the most powerful form of resistance. 13:34 Refusing to become the chattel that their masters believed them to be is what made slavery untenable and the Civil War inevitable, so make no mistake, slaves fought back. 13:45 And in the end, they won. I'll see you next week. Credits 13:48 Crash Course is produced and directed by Stan Muller. 13:50 The script supervisor is Meredith Danko. 13:52 Our associate producer is Danica Johnson. 13:54 The show is written by my high school history teacher Raoul Meyer and myself. 13:57 And our graphics team is Thought Cafe. 13:58 Every week, there's a new caption to the Libertage, but today's episode was so sad that we couldn't fit a Libertage in... 14:04 UNTIL NOW! [Libertage Rock Music] 14:08 Suggest Libertage caption in comments, where you can also ask questions about today's video that will be answered by our team of historians. 14:13 Thanks for watching Crash Course, and as we say in my home town, don't forget to be abolitionist.

A biografia di Dante, con le notizie dei suoi ascendenti, dei suoi familiari, del suo matrimonio, dei suoi figli, è stata ricostruita da molti autori. Ricordo fra gli altri il piccolo, classico libro di Michele Barbi, che ad oltre ottanta anni di distanza consiglierei ancora per un primo approccio. In queste pochissime pagine mi limiterò a richiamare gli elementi cronologici essenziali, a contestualizzarli nella storia generale e a dire di alcuni momenti della vita di Dante e di alcuni fatti di storia generale rievocati nella Commedia. A tante questioni, vicende e persone, Dante compreso, darò corpo nelle prossime letture. Per adesso uno scheletro. Dante nacque fra il maggio e il giugno del 1265. Un anno che si pone tra la vittoria militare ghibellina di Montaperti (4 settembre 1260) e la vittoria militare guelfa di Colle Val d’Elsa (17 giugno 1269). Dante avrebbe rievocato nella Commedia ambedue questi scontri (Inf. X e Pg. XIII), ancorandoli rispettivamente a un protagonista e ad una osservatrice. L’anno della nascita di Dante è anche un anno cruciale nella storia dell’arte. Nicola Pisano e i suoi aiutanti costruirono nella cattedrale di Siena un pulpito marmoreo che è tra le grandi espressioni di un rinnovamento della cultura artistica; nell’équipe di Nicola era anche Arnolfo di Cambio, altro protagonista di quella strepitosa stagione. Certo non insensibile alle arti figurative ed anche ai momenti di innovazione, come testimoniano alcuni luoghi della Commedia, Dante non disse però nulla dei grandi scultori del Duecento e del primo Trecento. Quando egli era ancora un fanciullo (aveva circa dodici anni) il padre, come era consuetudine, combinò il suo matrimonio. Scelse una donna della consorteria nobiliare dei Donati, Gemma di Manetto, alla quale fu assegnata una dote di 200 lire di fiorini d’oro: somma non piccola ma non strepitosa, della quale Gemma non poté fruire se non tardivamente e in parte, essendo stati sequestrati i beni e i diritti di Dante al momento della condanna all’esilio (1302). Con Gemma Donati Dante ebbe due o forse tre figli maschi e una figlia femmina, persone di una sola delle quali, il figlio Pietro, abbiamo notizie copiose e interessanti. Dante era ancora un bambino quando un grande rivolgimento politico si svolgeva in Italia e Toscana. Dopo la vittoria ghibellina di Montaperti lo schieramento guelfo si riorganizzò, e dal 1269 ottenne una preponderanza in Toscana grazie alla vittoria militare di Colle di Val d’Elsa e soprattutto grazie ad una forte iniziativa dei papi Urbano IV e Clemente IV e all’intervento di Carlo d’Angiò, figlio del re di Francia, vittorioso sui ghibellini a Benevento nel 1266, incoronato re di Sicilia nel 1270 ed aspirante ad una supremazia politica in Italia. Dante sistemerà Carlo d’Angiò e il figlio, re Carlo II, in luoghi diversi del Purgatorio, manifestando nei loro confronti una sostanziale distanza nel giudizio morale (Pg. XX). Esprimerà un giudizio severo su Clemente IV (Pg. III), di Urbano IV non parlerà, e collocherà in Purgatorio il capofila del movimento ghibellino, re Manfredi (Pg. III). Ma nei confronti di Manfredi esprimerà, se non una adesione politica, una forte simpatia umana, ed una umana pietas dedicherà a Corradino, ultimo esponente della casa sveva, fatto giustiziare da Carlo d’Angiò (Pg. XX). Tutto questo “secondo round” del conflitto ghibellino-guelfo, svoltosi tra la morte di Federico II di Svevia (1250) e l’incoronazione di Carlo d’Angiò (1270), vide scenari di grande complessità, e si è accennato come furono complesse, non univoche, le valutazioni che Dante espresse nella Commedia. Complessa fu anche l’evoluzione politica delle città italiane, segnatamente di Firenze. Nel corso degli anni Settanta si andò accentuando la cristallizzazione del conflitto tra nobili e “popolari”, ma si innestò su di esso il problema del contenimento dello strapotere delle grandi famiglie: quei “magnati” o “grandi”, come si dissero, che per tradizione militare e atteggiamento di comando, ricchezza, ampiezza di clientele, potevano avere un ruolo destabilizzante sulla vita civile della città. I ceti dominanti comunali, ampiamente commisti di famiglie nobili e famiglie di mercanti e artigiani, tentarono politiche che da un lato contenessero il contrasto guelfo-ghibellino e da un lato ponessero limiti al potere delle grandi famiglie di ambedue le parti. Tutto questo si concluse in solenni atti di pacificazione tra famiglie e in leggi che vietavano ai potenti l’accesso ad alcune cariche di governo, imponevano ad essi garanzie contro le eventuali offese ai “popolari” e comminavano pene severe in caso di turbamenti dell’ordine pubblico. A Firenze il momento pacificatorio ebbe un suo esito compromissorio e dunque instabile nel 1280 e la legislazione antimagnatizia ebbe un esito altrettanto problematico nel 1293, in ambedue i casi con un ritardo rispetto ad altre realtà comunali dell’Italia centrale quali Siena e Bologna. Nel frattempo, la rivolta siciliana del 1282 (Par. VIII) abbatté il potere di Carlo d’Angiò nell’Italia meridionale, lo intaccò ovunque e vide la contrapposizione all’angioino della casa reale di Aragona, che si volle erede di Manfredi e nuovo sostegno del ghibellinismo. A lungo sarebbero state realtà politiche contrapposte il regno aragonese di Sicilia e il regno angioino di Napoli. Dante avrebbe collocato nel Purgatorio, vicini l’uno all’altro, quei regnanti che in terra erano stati nemici tra loro (Pg. VII), e avrebbe espresso nell’insieme della questione angioino-aragonese giudizi un po’ ambigui. Dobbiamo pensare che ai suoi occhi nessuno di quei sovrani meritasse una supremazia tale da poter rivendicare un ruolo imperiale, l’unico che Dante riteneva veramente importante per le sorti dell’Italia. Mentre si dispiegava quel nuovo scenario degli anni Settanta e Ottanta del Duecento Dante viveva le sue prime esperienze di matrimonio e di paternità, proseguiva e completava una formazione culturale di alto livello, retorica, letteraria e filosofica, e avviava la propria partecipazione alla vita militare, politica e amministrativa della sua città. Questo però non prima della fine degli anni Ottanta. Nel giugno del 1289 (aveva dunque ventiquattro anni) partecipò alla battaglia di Campaldino, scontro tra i guelfi fiorentini e i ghibellini di Arezzo, che avrebbe rievocato nella Commedia (Pg. V). Pochi anni dopo si attuava, come ho accennato, la legislazione antimagnatizia fiorentina per iniziativa di Giano della Bella, che Dante collocherà nel Paradiso con una ampia e complessa valutazione (Par. XVI). Contestuale a questa legislazione “popolare” fu l’obbligo di iscrizione ad una delle Arti per chi volesse partecipare ai Consigli. Nel 1295 Dante si iscrisse all’Arte dei medici e speziali, e dello stesso anno è un suo, forse primo, intervento in uno dei Consigli cittadini. Cinque anni prima era morta una nobile donna, Beatrice, della quale Dante si era innamorato e per la quale sveva scritto, continuando a scrivere dopo la morte di lei, una serie di poesie raccolte in un libro di taglio autobiografico, la Vita nova. Dopo quello del 1295 molti altri interventi di Dante in Consigli diversi sono documentati in questi ultimi cinque anni del Duecento; in alcuni di essi, e poi in una ambasceria al Comune di San Gimignano del maggio 1300, Dante si adoperò per contrastare l’aggressiva e destabilizzante politica attuata in Toscana dal papa Bonifacio VIII, che il poeta dirà atteso in inferno insieme ad altri papi simoniaci (Inf. XIX)(il viaggio della Commedia è immaginato nel 1300, il papa morì nel 1303, così Dante poteva solo anticipare la condanna divina). Nell’aprile del 1301 Dante fu nominato soprastante all’esecuzione di certi lavori pubblici, nello stesso mese e poi ancora nel giugno e nel settembre intervenne in alcuni Consigli. Ho detto nella lettura su Ulisse della modalità scarna secondo la quale erano registrate le delibere, così non ci si deve attendere di leggere un ampio resoconto del discorso pronunziato dal divino poeta; è però abbastanza certo che egli intervenisse per contrastare la politica di Bonifacio VIII e l’intervento del principe francese Carlo di Valois, che il papa aveva fatto intervenire, sotto pretesto pacificatorio, per affermare la propria supremazia in Toscana (di Carlo Dante farà cenno in Pg. XX, canto fondamentale per conoscere l’atteggiamento del poeta verso la casa reale di Francia e i suoi rami). Intorno a queste opzioni politiche si era andata formando una contrapposizione tra un partito filopapale, che si disse dei guelfi Neri, e un opposto gruppo politico ostile alla politica di Bonifacio VIII e Carlo di Valois, che si disse dei Bianchi, nel quale Dante si schierò. La divisione dei Bianchi e dei Neri si era inizialmente definita a Pistoia e fu importata a Firenze, dove trovò i rispettivi capofila in due clan familiari, i Cerchi e i Donati. Poco tempo dopo gli interventi di Dante nei Consigli, nel gennaio 1302, il podestà Cante dei Gabrielli da Gubbio, in seguito all’istruttoria del giudice Paolo da Gubbio, preposto alle questioni di corruzione, ingiuste estorsioni e lucri illeciti, pronunziava la condanna di quattro cittadini, tra i quali Dante, i quali avrebbero commesso quei reati mentre erano nell’ufficio dei priori, il massimo organo di governo comunale. Dante e gli altri imputati si erano nel frattempo allontanati da Firenze, o come nel caso di Dante erano già lontani per diversi motivi, e non si presentarono in un giudizio del quale molto probabilmente presagivano l’esito. Furono pertanto condannati in contumacia (la giustizia dell’epoca riteneva la contumacia equivalente ad una confessione di colpevolezza). La penalità era enorme, 5000 fiorini per ciascuno, e se non fosse stata versata si sarebbe proceduto, come di norma, alla distruzione dei beni dei condannati, per non dire di altre conseguenze (confino, interdizione da uffici eccetera). Nota. Il testo che ho citato in apertura è Michele Barbi, Vita di Dante, Firenze, Sansoni, 1961. Era stato scritto per l’Enciclopedia Italiana, poi fu edito da Sansoni nel 1933 con il titolo Dante. Vita, opere e fortuna. Delle altre biografie ricorderò solo quella di Giorgio Petrocchi, Biografia. Attività politica e letteraria, nell’ Appendice dell’ Enciclopedia dantesca, 1978, pp. 1-53. Fonte documentaria primaria per la biografia di Dante e dei suoi familiari è il Codice diplomatico dantesco, che meriterà un discorso a suo luogo. Autore: Paolo Cammarosano

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