Unit 11 – Living on Earth I: Evolution and Extinction Easy Come, Easy Go-- Evolution and Extinction

Unit 11 – Living on Earth I: Evolution and Extinction 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.

Unit 11 – Living on Earth I: Evolution and Extinction 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.

Unit 11 – Living on Earth I: Evolution and Extinction 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).

Unit 11 – Living on Earth I: Evolution and Extinction 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…)

Unit 11 – Living on Earth I: Evolution and Extinction 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.

Unit 11 – Living on Earth I: Evolution and Extinction 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.