Review Unit 11 Introduction
You have reached the end of Unit 11! Double-check the list of requirements on the Unit 11 Introduction page and the Course Calendar to make sure you have completed all of the activities listed there.
Unit 11 Overview
Review of the main topics and ideas you encountered in Unit 11.
Easy Come, Easy Go--Evolution and Extinction
- Kids include experiments--are not identical to parents
- Differences affect ability to survive to have kids (natural selection)
- Kids are similar to parents--kids receive a bit more or less of what makes parents biologically successful
- This over time gives evolution--successful experiments accumulate, unsuccessful ones eliminated, changing living things over time
- Changes to living organisms are not passed on (kids of pierced-ear parents don’t have pierced ears!)--just reproductive experiments are passed on
The Unbroken Chain
- Law of Faunal Succession suggests evolution
- Evolution predicts transitional forms over time, special creation or catastrophism don’t
- Transitions found, strongly supporting evolution:
- Transitions common in commonly fossilized types
- And less common in less-commonly-fossilized types
- New species often emerge geologically rapidly from small populations (changing smaller group easier)
- Transitions found as often as evolution predicts; fossil record incompatible with competing hypotheses.
Taking Care of Business
- Theory of evolution is explanatory, predictive, and useful
- Germs are evolving antibiotic resistance, and the scientists trying to keep us alive are using knowledge of evolution
- Computer scientists mimic evolution to solve complex problems (evolutionary computing).
Teach the Conflict?
- Scientifically, there is no conflict--much to learn and do, but no serious problems or competitors
- In particular, evolution is:
- Consistent with second law of thermodynamics
- Supported by fossil record and age dating
- Not anti-religion (supported by many religious groups)
- Widespread scientific consensus that so-called competitors (e.g., “intelligent design”) are not science
- “Teaching the conflict” means not teaching science (note that to question evolution, Kansas School Board invented a new definition of science…)
Extinction Can Ruin Your Whole Day
- Slow background of extinction (population fluctuations sometimes hit zero, which is extinct)
- Occasional mass extinctions:
- end-Paleozoic: heat-caused loss of ocean oxygen?
- end-Mesozoic: meteorite
- Dinosaurs doing just fine until meteorite got them
- Freed ecological jobs (“niches”), allowing evolution to produce large mammals over last 65 million years.
The Dinosaur Killer
- Evidence: extinction at odd bed with much iridium (common in meteorites), soot, high-pressure shocked quartz, melted-rock droplets, Caribbean giant-wave deposit; right-age giant crater Yucatan Peninsula
- Mechanisms: meteorite blasted things up, fire from heat of fast-falling things, then cold from sun-block of slow-falling things, with acid rain
- Still big rocks out there--averaged over millions of years, perhaps as dangerous as commercial airline crashes, but not nearly so dangerous as car crashes.
Following are some supplementary materials for Unit 11. While you are not required to review these, you may find them interesting and possibly even helpful in preparing for the quiz!
Comments or Questions?
Please feel free to send an email to ALL of the teachers and TA's through Canvas conversations with any questions. Failure to email ALL teachers and TA's may result in a delayed or missed response. See "How to send email in GEOSC 10" for instructions