facts are just the minutia of Science by themselves they can be right or wrong but a theory is something that's been tested and tested over and over again built on revised it continues to be reworked and revised Dr Miller would you agree that Darwin's theory of evolution is not an absolute truth well I certainly would for the very simple reason that no theory in science and no theory is ever regarded as absolute truth we don't regard atomic theory as truth we don't regard The Germ theory of disease as truth we don't regard the theory of
friction as truth we regard all of these theories as Wells supported testable explanations that provide natural explanations for natural phenomena should we regard Darwin's theory of evolution as tentative we should regard all scientific explanations as being tentative and that includes the theory of evolution science is about discovering the unknown what we don't know I don't focus on what we know as a scientist I want to find new things that tell me about what I don't know as the plaintiffs testified that quest to investigate the unknown has led to the discovery of some of the strongest
evidence for evolution Darwin was convinced that species evolve over time through natural selection acting on inherited traits but he had no idea how how those traits arose or how they were passed from generation to generation when 20th century scientists discovered the role DNA plays in heredity they founded a new science called genetics that put Darwin's theory to the test virtually every cell in every living thing contains chromosomes which are made of densely packed strands of DNA that function as a blueprint of the individual organism's characteristics during reproduction chromosomes from each parent replicate and Shuffle their
parts to produce new chromosomes then each parent passes chromosomes to offspring but the process is imperfect along the way DNA is subject to random mutations or mistakes giving each offspring its own unique blueprint sometimes this produces characteristics in offspring that are benign other times it produces harmful characteristics like a misshapen Wing but occasionally the process gives rise to a beneficial trait for example a butterfly whose coloration mimics another species that tastes bad to birds about a hundred years after Darwin proposed that natural selection acts on new traits appearing in a population genetics revealed the biological
mechanism that gives rise to those traits in the first place and therefore you could say that when modern genetics came into being everything in Darwin's theory was at risk could have been overturned if it turned out that genetics contradicted the essential elements of evolutionary theory but it didn't contradict them it confirmed them in great detail and as Miller would testify a genetics paper published less than a year before the trial had confirmed what has long been the most inflammatory part of Darwin's theory the common ancestry of humans and apes that paper explored a curious discrepancy
in our chromosomes the cells of all great apes like chimpanzee disas gorillas and orangutangs contain 24 pairs of chromosomes if humans share a common ancestor with Apes you'd expect us to have the same number but surprisingly human cells contain only 23 pairs the question is if evolution is right about this common ancestry idea where' the chromosome go well Evolution makes a testable prediction and that is that somewhere in in the human genome we ought to be able to find a piece of Scotch tape holding two chromosomes together so that our 24 pairs two of them
were pasted together to form just 23 and if we can't find that then the hypothesis of common ancestry is wrong and evolution is mistaken next slide to solve this riddle for the court Miller would show how scientists discovered traces of our evolutionary past buried in the very structure of a chromosome carried by All Humans typically on the ends of every chromosome you should find special genetic markers or sequences of DNA called telome and in their midd you should find different genetic markers called centrom mirors but if a mutation occurred in the past causing two pairs
of chromosomes to fuse we should find evidence in those genetic markers telome not only at the end of the new chromosome but also at their middles and not one but two centrom finding a structure like this in our chromosomes would explain why humans have one pair fewer than the great apes and if we don't find that then evolution is in trouble next slide lo and behold the answer is in chromosome number two all of the marks of the fusion of those chromosomes predicted by common descent and evolution all those marks are present on human chromosome
number two so the case is closed in a most beautiful way and that is the prediction of evolution of common ancestry is fulfilled by that lead pipe evidence that you see here in terms of tying everything together that our chromosome formed by the fusion from our common ancestor is chromosome number two Evolution has made a testable prediction and it has passed so modern genetics and molecular biology actually support evolutionary theory they support it in great detail and the closer we can get to looking at the details of the human genome the more powerful that evidence
has become Darwin didn't even know about molecular biology and DNA yet that's where some of the most profound evidences is being uncovered today think about that that somebody in the 1800s made predictions that's are being confirmed in molecular biology labs today that's a very profound statement of a very successful Theory not a single observation not a single experimental result has ever emerged in 150 years that contradicts the general outlines of the theory of evolution any theory that can stand up to 150 years of contentious testing is a pretty darn good theory that's what evolution is
and the deep understanding of evolution as proposed by Darwin has genetics unlocked many of the secrets of life life it's an explanatory framework within which all the rest of biology fits right it's something that we use uh in Practical biological applications medicine agriculture industry when you're getting a flu vaccine that really depended upon evolutionary knowledge in many many specific ways Evolution makes a practical difference it's not just something that happened to the past evolution is happening now so if evolution has stood up to all this scrutiny what about intelligent designle does it play by the
same rules if you invoke a non-natural cause a Spirit Force or something like that in your research I have no way to test it so Supernatural causation is not considered part of science yeah I hesitate to beg the patients of the court with this but being a Boston Red Sox fan I can't resist it one might say for example that the reason the Boston Red Sox were able to come back from three games down against the New York Yankees was because God was tired of George steinbrener and wanted the Red Soxs to win in my
part of the country you'd be surprised how many people think that's a perfectly reasonable explanation for what happened last year and you know what it could be true but it certainly wouldn't be sign science it's not scientific and it's certainly not something we can test the fundamental problem with intelligent design is that you can't use it to explain the natural world it's essentially a negative argument it says Evolution doesn't work therefore the designer did it Evolution doesn't work therefore we win by default but when you ask them what does intelligent design tell you about nature
uh does it tell you uh what the designer did does it tell you what the designer used to design something with does it tell you what purpose the designer had for Designing something does it tell you when the designer did it why the designer did it doesn't tell you anything like that basically it's a negative argument and you can't build a science on a negative argument after 3 weeks of testimony on the nature of science the evidence for evolution and the failings of intelligent design The plaintiffs had presented their case to
