Lecture Notes-04 Biology 1004
North Arkansas College
Topic: Evolution and Bioethics
Piltdown Man: Ethics in Science
- What is Piltdown Man?
- Possible missing link between man and primate.
- Significance; prove concept of evolution.
- England in 1912.
- Discovery in a pit where other fossils are found.
- Dawson given credit for discovery.
- Took approximately 40 years to prove it was a fake (using carbon dating).
- Lesson A- Do not believe everything published. Do not jump to conclusions. Pressure for performance may have been motivation.
Independent Birth of Organisms
- Genomes are primarily fixed and do not undergo extensive changes that would allow major characteristic changes in a short time (several hundred years).
- Proposal is that life began with DNA produced from chemicals present in primordial "soup". Gradually, links of the DNA chain increased; providing more characteristics.
- Out of mass, several different species arose; versus one common ancestor for all species.
- There is so much difference between blood of sharks and that of humans that differences in DNA could not account for the evolution of one from the other.
Regarding #2, there is support for the possibility of life originating from basic chemical elements. In 1952, Urich and Miller took gases believed to be present in primitive atmosphere and sparked with heat and electrical charge. They found all of the amino acids; short peptides, and the basic unit of DNA/RNA. Some definite similarities occur among widely varying species to suggest they arose from a common ancestor.
- DNA/RNA; made of same chemical molecules.
- Embryos; all look same for most species.
- Humerus, radius, ulna, carpus, metacarpus, phalanges, pterodactyl, dolphins, bats, sheep, seals and humans all contain same characteristics.
