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i) The fossil record shows gradual changes , and also shows branching patterns of phylogeny. ii) Geology, Physics and Astronomy independently conclude that the earth is 4+ billion (=thousand million) years old.
iii) DNA base sequences (genomes) from different kinds of living animals and plants confirm the same phylogenetic trees as did the fossil records of these same groups. iv) Anatomical and embryological evidence each support the same phylogenetic trees as do the DNA base sequences.(for example: gill slits in early human embryos) v) Antibiotic resistance by germs (unfortunately!) evolves constantly by natural selection in favor of genes that produce resistance. (tuberculosis is one of many examples) vi) By means of selective breeding , you can deliberately "evolve" large changes in animals and plants. (examples include the different breeds of dogs, cabbage etc.)
vii) Evolution can be simulated inside computers , by
>> random "mutations" in duplicate programs >>> competition between these different programs Based simply on how genes work, evolution could be predicted.
ix) Within each person's body, during their lifetime, their immune system turns out to work by selection of random differences in the DNA that codes for the binding sites of antibody proteins. This is logically a form of natural selection.
This will be explained later in the course, and is extremely important medically. "Autoimmune diseases" like Lupus and MS result from failure to weed out cells with DNA for anti-self Let's vote on whether the following is an unfair analogy :
Suppose that someone were to announce: What might they mean by this?
a) That they don't believe running water will wash away soil? b) That they don't believe that the Grand Canyon was produced by water wearing away soil and rocks for millions of years? c) That millions of years of water wearing away rocks wouldn't produce canyons? (even in principle?) d) That the Grand Canyon was created recently to look as if it had been the result of millions of years of erosion , but really only the last few thousand years worth of wear was actually caused by erosion? And fossils were put in the rocks to trick us? Other analogies: Does the sun comes up in the morning because the earth rotates on an axis? Does the earth rotate because of inertia? Is the shape of the earth's orbit around the sun caused by the laws of gravity? A person might think that God causes these phenomena by means of the laws of physics . Another person might think that God causes these phenomena directly, and that the results only happen to be the same as would be predicted by the laws of gravity and inertia. Courses in physics and astronomy don't leave out the laws of gravity, to conform with this latter opinion. For a biology course to leave out evolution is equivalent to leaving gravity out of astronomy or physics courses. You don't have to believe Darwinian evolution, but you should understand what you are not believing, and also know what evidence supports it. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Anonymous Take Home Questionnaire:(please hand in your answers Monday)I will count percentages of different answers, and post these by next Wednesday.) Do you feel that you understand how evolution is supposed to work? YES? NO? Do you understand what evidence biologists think confirms the truth of evolution?
Please rank the arguments listed in the lecture notes as i, ii, iii, iv etc. The most convincing was? The least convincing was? Is there particular part of this evidence that you don't understand ? Which parts? Is there (are there) particular parts of this evidence that you DO NOT find convincing ? EITHER: you understand the idea; but you do not agree that the facts are true OR You don't agree that these support or prove Darwinian evolution? Did the analogy to erosion and the Grand Canyon make sense? YES? NO? Was this a fair analogy? Or an unfair analogy? Why? Did you learn any new things about evolution from the lecture ? Did it change your mind about the truth of evolution? YES? NO? Did it change your mind about whether evolution is "just a theory " YES? NO? Should evolution be left out of high school biology courses? What about college courses? Should theories of relativity, clonal selection theory of immunity, quantum theory etc. also be left out. Other comments that you want to make? What aspects of evolution do biologists seem to ignore? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Historically, what have been serious arguments AGAINST Darwinian evolution?
1) Not enough time since the formation of the earth and stars. 2) Dilution of genetic differences. But Mendel's discoveries solved this problem. 3) Not enough genetic variation. Discovery of mutations also solved this problem. 4) "Piltdown man" missing link human fossils turned out to be a deliberate hoax. (this fooled people from 1913 to ~1953) But thousands of real human ancestral fossil skeletons have been found, that were not fakes.
5) Claims of evidence for Lamarckian evolution (inheritance of acquired properties)
> Kammerer's research in 1920s Vienna > Arthur Koestler's book "Case of the Midwife Toad"; 6) Difficulties of explaining separation (isolation) of species gene pools from each other. ("the Modern Synthesis" between genetics and evolution: 1930s)
7) What about "missing links" in the fossil record?
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