* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Evolution
Survey
Document related concepts
Objections to evolution wikipedia , lookup
Sociocultural evolution wikipedia , lookup
Unilineal evolution wikipedia , lookup
On the Origin of Species wikipedia , lookup
Creation and evolution in public education in the United States wikipedia , lookup
Jewish views on evolution wikipedia , lookup
Hindu views on evolution wikipedia , lookup
Punctuated equilibrium wikipedia , lookup
Creation and evolution in public education wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Acceptance of evolution by religious groups wikipedia , lookup
Transcript
The Theory of Evolution by Natural Selection The Theory of Evolution is… Arguably, the most important scientific development of the last 200 years. A scientific, i.e. evidence based, theory of the origins of human and other life forms. A powerful explanation of the change, variation, and diversity we see in the natural world. An alternative idea to the belief that human life was designed and created by God. Evolution in a Nutshell… Life has developed over many millions of years and began with simple single-celled creatures By chance, species mutate and develop into more complex life forms All life forms depend on resources so the survival of new species depends on their relationship with the environment around them A species unsuited to its environment will die out, but ones that are well-adapted survive Charles Darwin The Theory of Evolution by Natural Selection is most closely associated the great naturalist Charles Darwin (1809 – 1882). Darwin’s Early Life Darwin was the son of a doctor but was put off medicine by watching operations He had intended to become a minister in the Church of England but his real interest was natural history Like most people at the time, the young Darwin accepted the view that God had created different species suited to their environments and that they did not change The Voyage of the Beagle In 1831 however, he was invited to join a fiveyear voyage around the world on HMS Beagle… The Voyage of the Beagle in Context Darwin’s ideas reflected the intellectual context of the time and the philosophical challenge to religious authority associated with Philosophers such as Kant and Hume. Although many people believed the world was about 6000 years old, geologists like Darwin’s friend Charles Lyell were coming to think that the world was a lot older; e.g. fossils. If the world were a lot older, then over time, lots of little changes might add up to big changes, even new species. What Darwin Found As he travelled, Darwin started thinking about the geographical distribution of wildlife and the fossils he found for animals that no longer existed. This led him to come up with the idea that life forms were not fixed but mutable – i.e they changed or ‘evolved’ over time. Darwin’s Finches I For example, Darwin noticed on the Galapagos Islands that finches with big beaks lived on an island with large nuts they could eat, while small beaked birds lived on an island with lots of small seeds Darwin’s Finches II Given the fact that the islands were close together, he came to think that the distribution of the different Finches was determined by varying suitability to different environments. Finches with the ‘wrong’ shaped beak would not survive, and therefore, would not have offspring ‘Natural Selection’ I What Darwin came to realize was that… within a species some members have characteristics better adapted to their environment than others. These members will continue to survive and breed whilst others not as suited to their environment will die out. Eventually the characteristic becomes the norm for the species. This process is called natural selection. ‘Natural Selection’ II As with most scientific ideas, ‘natural selection’ makes certain assumptions…that Living things reproduce freely and this results in competition for resources - food and space. Animals prey on each other. Offspring differ slightly from their parents. Many characteristics are inherited The longest-living members of a species are likely to reproduce the most These are the characteristics most likely to be passed on to succeeding generations… Accidential mutation Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by N______ S________ was developed by Charles D_____. Challenging the idea that species are f___ and that humans were c____ by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ______, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted Darwin fixed mutate created Selection evolved Natural environment resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural S________ was developed by Charles D_____. Challenging the idea that species are f___ and that humans were c____ by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ______, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted Darwin fixed mutate created Selection evolved environment resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles D_____. Challenging the idea that species are f___ and that humans were c____ by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ______, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted mutate created environment Darwin fixed evolved resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are f___ and that humans were c____ by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ______, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted mutate created environment fixed evolved resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were c____ by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ______, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted mutate created environment evolved resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life _______ over many millions of years and began with simple single-celled creatures. By ____, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its __________ will die out, but ones that are well-_______ survive. chance adapted mutate environment evolved resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By ____, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its _________ will die out, but ones that are well-______ survive. chance adapted mutate environment resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species ______ and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its _________ will die out, but ones that are well-______ survive. adapted mutate environment resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species mutate and develop into more complex life forms. All life forms depend on ________ so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its _________ will die out, but ones that are well-______ survive. adapted environment resources species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species mutate and develop into more complex life forms. All life forms depend on resources so the survival of new _______ depends on their relationship with their surroundings. A species unsuited to its _________ will die out, but ones that are well-______ survive. adapted environment species Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species mutate and develop into more complex life forms. All life forms depend on resources so the survival of new species depends on their relationship with their surroundings. A species unsuited to its _________ will die out, but ones that are well-______ survive. adapted environment Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species mutate and develop into more complex life forms. All life forms depend on resources so the survival of new species depends on their relationship with their surroundings. A species unsuited to its environment will die out, but ones that are well-______ survive. adapted Evolution: Task 1 Copy and Complete the following: The Theory of Evolution by Natural Selection was developed by Charles Darwin. Challenging the idea that species are fixed and that humans were created by God, it claims that life evolved over many millions of years and began with simple single-celled creatures. By chance, species mutate and develop into more complex life forms. All life forms depend on resources so the survival of new species depends on their relationship with their surroundings. A species unsuited to its environment will die out, but ones that are well-adapted survive. ‘The Origin of Species’ Although Darwin wrote out a version of his ‘species theory’ in 1842, he did not publish his ideas for nearly two decades. Q. Why do you think Darwin delayed publishing ideas for so long? By 1858, however, Darwin had become aware that another naturalist, Alfred Wallace, working in Malaya, had developed very similar ideas. The two men presented their ideas to the Linnean society in 1858 but attracted little interest. In 1859, Darwin published ‘On the Origin of Species’, which set out his ideas in detail. The Impact of Darwin’s Ideas The initial response to the Origin of Species was relatively muted. This reflected the fact that many scientists at the time were also religious. The division between science and belief did not really exist. Some scientists, even Darwin himself perhaps, retained a faith in God But as the implications of Darwin’s theory became appparent, so the controversy grew. The Implications of Origins I Darwin’s Christian faith had already begun to fade before his eldest daughter Annie died at the age of 10 in 1851. But Darwin probably delayed publishing his theory because he saw the damaging social implications for a still dominant Christianity. He might even been wary of blasphemy laws. Why? Because his theory suggested that life on earth developed randomly and blindly. It removed any need for a designer/creator God! The Implications of Origins II Most disturbingly, for supporters of the religious view, Darwin argued that while human beings had ‘noble qualities’ and ‘godlike intellect’, we shared a common biological ancestry with the so-called ‘lower’ species. Far from a ‘crown of creation’, we were simply a newer, more successful form of primate; i.e. humans are just well-adapted, hairless apes. Task 2 Q.1 Why did Darwin’s theory pose a threat to existing religious ideas about the origins and status of human life? Because his theory suggested that life on earth developed randomly and blindly, it removed the need for a creator God! While human beings might have ‘noble qualities’ and ‘god-like intellect’, Darwin argued that we share a common ancestry with the so-called ‘lower’ species: i.e we are simply a newer, more successful form of primate; well-adapted, hairless apes. Problems in Darwin’s Theory Another reason, Darwin might have held back on his theory may have been the fact that there were some unresolved issues with it. Crucially, he could not demonstrate the process of evolution, only infer it from the evidence available to him. It was based on circumstantial evidence - e.g. fossils, the variety and location of species rather than empirically verified experiments. He also recognise that he had not identified the mechanism of evolution itself. How were traits developed and passed on? DNA – The Building Blocks of Life This issue was addressed nearly a century after the publication of Origins with the discovery of DNA – deoxyribonucleic acid. Hitherto, people saw it as self-evident that we inherited some qualities from our parents. But other qualities were not. The discovery of DNA by Crick and Watson in the 1950s enabled scientists to explain exactly how this happened . Mutations Some qualities are developed over a lifetime and are not passed down over time – e.g. skills like playing an instrument have to be learnt But the physical potential of all living things is determined by genes passed on in DNA. Every now and then a mutation occurs. If that mutation gives an advantage in passing on DNA then the mutation survives and becomes the norm Task 3 Q. What were some of the issues with Darwin’s theories initially? Darwin could not demonstrate the process of evolution through experiments, only infer it from the circumstantial evidence available to him, e.g. fossils along with the variety and distribution of species. Neither had he identified the mechanism of evolution itself; how traits were developed and passed on. Task 4 Q. How did other scientists develop the Theory of Evolution to address these issues? Although people saw it as self-evident that we inherited some qualities from our parents, it was only after the the discovery of DNA – deoxyribonucleic acid – by Crick and Watson, that scientists could explain how it happened. The physical potential of all living things is determined by genes passed on in DNA. Every now and then a mutation occurs. If that mutation gives an advantage in passing on DNA then the mutation survives and becomes the norm Evolutionary Theory Now Modern Darwinians argue that life on Earth began in a ‘primordial soup’ where inorganic elements, subjected to ultraviolet light or electrical storms, underwent a chemical change to organic molecules. Eventually these organic molecules came together to form simple, single-celled organisms able to replicate or reproduce themselves. Over time, these mutated into ever more complex forms. The Darwinian View of Humans Most importantly, proponents of the Darwinian view such as Richard Dawkins argue that the process of evolution is random or blind. All that is needed is lots of time. Other than passing on our genetic inheritance they say there is no purpose to it; no guiding hand, no design, no God! This contradicts the religious view that humans have a special place and purpose in the universe The Darwinian View of Humans Dawkins et al would argue that humans are not ‘special’ but a successful accident or mutation. In the future, however, (man-made?) changes in the environment and a failure to adapt could lead humans to die out like the dinosaurs, and be superseded by another form of life. Evolution: Task 5 If the Theory of Evolution is correct, the development and location of the various species on Earth has been shaped by the way new ‘mutations’ help or hinder survival and the ability to generate offspring. For example… …the shape of a bird’s beak will determine what food they can eat. They can only survive in environments where the right kind of food is available …the ability some animals have to run very quickly enables them to hunt and/or evade predators. …Polar Bears’ fur provides camouflage and warmth in icy areas where other animals cannot survive. Evolution: Task 5 Pick 3 of the following qualities and write a short paragraph discussing how they might give humans an evolutionary advantage: Skin colour Strength Courage Beauty Wealth Language Intelligence Men Driving Too Fast The Theory of Evolution by Natural Selection - Strengths It is based on and supported by a massive body of scientific research and evidence which links a range of scientific disciplines – biology, chemistry, physics, geology etc. It provides a convincing working explanation of observable realities such as… - The astonishing biodiversity of our planet. - Similarities and differences between species. - Mass extinctions and other major changes in the natural history of our world. - The development of human beings. The Theory of Evolution by Natural Selection – Strengths II Recent developments in Science e.g. the discovery of DNA and the development of genetics support Darwin’s insight. Our awareness of how important DNA is has already brought medical benefits. The idea that the process is blind removes the need to explain the origins of a supernatural creator God. It puts humans in charge their own destiny! The Theory of Evolution by Natural Selection – Limitations Much of evolutionary theory is based on circumstantial evidence and inference. Evidence could be interpreted in other ways. There are ‘gaps’ in the theory and the evidence supporting it… - E.g. incomplete fossil record which does not show intermediate species or ‘missing links’. Some complex life forms exist as parts of complete systems in which an intermediate form would not work. The Theory of Evolution by Natural Selection – Limitations Critics say it does not answer questions about the meaning and purpose of human life. The best that Darwinians such as Richard Dawkins can offer is the idea of the ‘selfish gene’ i.e. that life forms exist only to pass on their genetic information, their DNA. It seems to undermine the power and authority of religion without offering any moral guidance as to how we should try to live. The Origins of Human Life: Are Science and Religion Compatible? The Bible sets out a special, God-given role and purpose for humans. For Christians, our lives are made meaningful by our relationship with God. If the Theory of Evolution is true it calls these things into question. How might we think about the relationship between science and belief in the light of Darwinian ideas? Evolution v Revelation There are three basic positions or possible responses to this issue. 1. Evolution contradicts revelation – the science must be rejected. 2. Revelation contradicts evolution – Christianity must be rejected. 3. Revelation and Evolution both contribute to a full understanding of the origins of human life. 1. Rejecting Evolution Creationism As with the debate regarding the creation of the Universe, Creationists refuse to acknowledge the truth of anything that contradicts scripture. Accepting the Bible as fact is an act of faith. If it is not in the Bible it cannot be true. Evidence and argument are irrelevant. But not all Christians are comfortable with the circular argument that the truth of the Bible proves the truth of the Bible… Rejecting Evolution – Intelligent Design Some Christians, use science as a means to reject evolution, and propose an alternative – INTELLIGENT DESIGN! Using the Teleological argument (cf. Paley) they highlight the weaknesses in evolutionary theory. In particular, they reject the idea that the development and survival of species is down to the mechanism of chance. They also highlight what they see as gaps and flaws in the evidence used to support evolutionary theory. Rejecting Evolution – Intelligent Design II For example, they point out the ‘irreducible complexity’ of some organisms. They argue that the step by step process does not add up. E.g. a partly evolved wing is impossible to conceive without all the other parts being present. Or, they argue that many mutations are harmful and do not necessarily lead to whole new species. Intelligent Design - Strengths Uses evidence-based science, to argue against the chance mechanism. Addresses possible flaws and gaps in evolutionary theory. Avoids the extremes of literalist understandings of the Bible. Ties in with liberal Christian approaches to the interpretation of the Bible – God still the designer! Intelligent Design - Limitations Scientific argument is complicated and beyond the reach of ordinary people. Implies Biblical creation stories are not enough. As an alternative to Darwinian ideas, it is really an attempt to defend faith in God. It does not really overturn evolutionary theory or prove the existence of God 2. Rejecting Christian Belief – Scientific Materialism Many scientific materialists see evolution as fact rather than theory because of the weight of the supporting evidence, incomplete as it may be. It contradicts the Bible, therefore the Bible is wrong – there are other explanations for what was written – scripture is obsolete. Evolution is the best explanation we have for the origin and development of life on Earth. Intelligent design is not a scientific theory but a religious one – it is an argument for the existence of God which is faith-based rather than fact-based, i.e. bad science. Belief and Science: Either Or? On the face of it, the relationship between Christian Revelation based in the scriptural authority of the Bible and the modern scientific Theory of Evolution is irreconcilable. Yet there are many scientists who are Christians able to accept both Christian teachings and the findings of Darwinian evolutionary theory… 3. Revelation and Evolution both contribute to a Full Understanding of the Origins of Human Life Some scientists reject the aggressive atheism of scientists such as Richard Dawkins. They argue that science has its limitations, and that human origins can only be understood fully by utilising science in conjunction with Philosophy and Religion. Revelation and Evolution as Complementary Scientists such as Joel de Rosnay, point out the reductionist tendencies of science. Highlighting the limits of science as a way of understanding ‘life’, they suggest that religion and science should be seen as complementary rather than conflicting explanations for the origins and development of life. They understand evolution as the mechanism through which God created life on Earth according to the laws of nature, also established by Him. Revelation and Evolution as complementary They understand Genesis as a ‘myth’, as a symbolic account of creation. It is not intended as science but as a way of ‘revealing’ the nature of our relationship with God. They would say that our genetic similarity to other primates does not negate our ‘specialness’ but reminds us of our responsibilities to look after the natural world created by God. Evolution is just another form of God revealing Himself to us! Revelation and Evolution as complementary For such Christians, Evolution is about the physical dimension of life on Earth. For them, the Theory of Evolution has little to say about the spiritual aspects of living. That is the role of religion, to develop our spiritual relationship with the universe. If we are ‘special’, and created in the image of God, then the curiosity and intelligence that has led to the development of evolutionary theory is part of God’s plan for us… …to become more fully human.