Evolution in the News
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Nigel Collins Evolution in the news This article looks at the evidence for evolution GCSE key words Charles Darwin Fossils as a young man and considers the ongoing conflict between Evolution scientists and creationists. Natural selection Theory harles Darwin returned from his travels In his marvellous travel book, The Voyage of the around the world on HMS Beagle in 1836. Over C 20 years later, in 1859, he published On the Beagle (1839), Darwin gives you a vivid picture Origin of Species by means of natural selection. The book of his experiences and was much in demand and the first print run was soon you can follow him sold out. as he accumulates Darwin was one of many people involved in the observations that later accumulation of compelling evidence that the world contributed to his was a much older place than had been assumed on theory of how evolution the basis of biblical accounts of ‘creation’. However, occurs. he went further than the other gatherers of evidence for evolution and proposed a theory that described how the process of evolution might work — hence, On the Origin of Species by means of natural selection. Darwin’s theory of evolution is as much about mechanism — how it happens — as about cataloguing evidence that it has occurred (see Box 1). Facts and theories in science o t o F Since Darwin’s time many other scientists, both p o T professional and enthusiastic amateurs, have added more and more evidence to support the idea of G Read ‘Places to Visit’ on page 11 to find out Box 1 Darwin’s theory of natural evolution as a fact. Yet some people still say ‘it’s just a more about Charles selection theory’. Darwin. Darwin proposed that natural selection is the A theory in science is a general idea or explanation mechanism whereby new species evolve from earlier which has a lot of evidence to support it. The evidence species across millions of years. His observations for evolution is very wide-ranging. It includes that from and deductions can be summarised as follows: the fossil record, coupled with the dating of rocks in which the fossils are found, through to evidence from G Observation 1: Individual organisms within a population have great reproductive potential. comparative anatomy and adaptive radiation. There is also evidence in our proteins and in our genetic mate- G Follow the movement G Observation 2: The number of individuals in a of humans as they population usually remains approximately rial (DNA) that reveals how humans evolved, and our colonised the planet at constant. relatedness to our ancestors and to other organisms. www.bradshawfoundation. You can follow the spread of humans and their related- G Deduction 1: Many individuals fail to survive or com/journey reproduce. There is a ‘struggle for existence’ within ness in the website listed in the margin. a population. We can also observe evolution taking place in the short term, in moths and antibiotic resistant bacteria, G Observation 3: Variation exists within populations. for example. The theory of evolution has been tested endlessly and it continues to stand up. That is why G Observation 4: Although the organism’s most scientists now accept it as a fact. When Darwin environment can affect the extent of variation published his theory, shown, variation can be inherited. The evidence of fossils many people in England G Deduction 2: In the ‘struggle for existence’ those regarded the biblical individuals showing variations that are Fossils of organisms never seen before are being creation story as literal advantageous are more likely to survive, reproduce discovered all the time. The initially incomplete truth and believed that and have more offspring, who may inherit this picture of earlier life forms is being filled in steadily. the world was about advantageous variation. Last year a new fossil showing the divergence of bees 4000 years old. from ancestral wasps was found. Such finds make 18 Catalyst Left: Comparisons of DNA and fossil records suggest that humans and modern African apes evolved from a common ape-like ancestor L P S / a k e i s a P G Listen to a talk by Box 2 ‘Truth in Science’ Box 3 Scientists urge evolution lessons Steve Jones on ‘Why In September 2006 an organisation called ‘Truth in The world’s top scientists have joined forces to call creationism is wrong Science’, which believes in intelligent design and for ‘evidence-based’ teaching of evolution in and evolution is right’ irreducible complexity, sent DVDs to all secondary schools. and see some of his schools in the UK. The origins of this organisation A statement signed by 67 national science illustrations at can be traced back to a group of the same name in academies says evidence on the origins of life is www.royalsoc.ac.uk/page. asp?id=4400&tip=1 the USA, where the DVDs first appeared in 2002. It being ‘concealed, denied, or confused’ in some is quite easy to follow the affiliation of this group classes. It lists key facts on evolution that ‘scientific on the internet back to its creationist origins. evidence has never contradicted’. In America, court cases have led to ‘intelligent Read more, including the full statement, at: design’ being banned from science lessons. In http://news.bbc.co.uk/1/hi/sci/tech/5098608.stm England, the creationist position and its offshoots, based in belief rather than science, are also not ‘creationists’. They refuse to accept the scientific Most peoples of the regarded by the Department of Education as part evidence for evolution and instead say that their world have developed of science lessons. creationist myth offers a proper explanation of how stories that count as the world and the organisms in it came into existence. creation myths, evolutionary lineages clearer. New fossils fitting into Some creationists have put forward other ideas imaginative notions the story of the evolution of birds have also been about ‘intelligent design’ or ‘irreducible complexity’, about how living things were ‘created’. found recently. Archaeopteryx no longer sits alone but these do not stand up when examined in detail between birds and reptiles. against scientific evidence for evolution (see Box 2) or It has also become possible to look at the available when the logic of the particular examples given is evidence and make predictions. For example, palaeon- tested. tologists knew that some rocks of a particular age con- Today, creationists make up a small proportion tained fossil organisms that they thought were of the world’s Christians. Some people of other descended from different fossil organisms present in religious faiths have equivalent fundamentalist older rocks. They predicted that rocks known to be of views on creation. However, most Christians now an intermediate age would contain intermediate forms. recognise that our collective knowledge and under- Rocks of this age occurred in the Arctic — and scientists standing has moved on since the days when the found intermediate fossil fishes there in 2006. creation myth in the opening chapter of the Bible was first recorded and accept the fact of evolution. Creation myths and creationists They do not regard this as incompatible with their Despite the fossil evidence, and all the other evidence beliefs and wider faith. in support of evolution, some people still believe in creation myths as the literal truth. They are known as Nigel Collins teaches biology and is an editor of CATALYST. February 2007 19.