Evidence for evolution

Transcription

1 Evidence for evolution Prior to the late 1700's biologists thought life to be unchanging Plato and the allegory of the cave platonic ideals (DOG vs dogs) Judaic/Christian/Islamic Biblical creation of organisms all at once Linnaeus classified organisms into "types" which he thought were fixed (museums still store "type specimens") So what evidence changed everyone's minds? (and more since 1859 that has added to the argument) BUT FIRST

2 The argument between creationism and evolution is a philosophical one, based on which type of argument is used: scientific method or religious faith Two philosophies for understanding "the truth" (Note: we use both in our everyday lives) Each has limitations and strengths Science: - Limited to observables, requires data. - Amoral (note, this is different from immoral). + Falsifiable nature allows conflict resolution. Faith: - Objective evidence can't be used to resolve conflicts. + Addresses non-objective aspects of reality. + Moral.

3 The danger of looking to nature to decide what is "good" or "bad"

4 Scientific method weaknesses, 2 current political issues Abortion: when does life begin? conception vs birth - more consistent - less consistent - not pragmatic - more pragmatic Science can provide data, but is unable to define life in useful way. Gun control: what is the best set of laws for guns? very strict limits vs very few limits - more safe - less safe - less freedom - more freedom Science can provide data, but is unable to measure freedom in a quantitative way.

5 Faith-based method weaknesses, 2 examples: Q: Which team is the "best" NFL team A: Green Bay Packers: locally owned, most NFL championships (12), best QBs (Starr/Favre/Rodgers), best WR Hutson (105td,172xp,30int) Christianity & Islam disagree on a few things Jesus: Son of God (Christianity) or a great prophet (Islam) God: a trinity (Christianity) or unity (Islam) What criteria can possibly be agreed upon to resolve these conflicts?

6 Scientific theories require 2 major conditions: 1. The theory must be capable of being used to make predictions - otherwise its useless Note: these must be new predictions that haven t been tested yet - otherwise its too ad hoc 2. The predictions must be falsifiable by some conceivable observation - otherwise how can you resolve conflicts?

7 How science, not faith, works. Observation or question Scientific theory (more than one idea) Hypothesis (idea) Hypothesis wrong, theory weakened Prediction incorrect? Hypothesis true, theory strengthened Prediction correct? Prediction Test prediction Theories: theory of gravity, germ theory of disease, theory of evolution, etc. Hypotheses: specific and focused questions.

8 "Faith and reason are like two wings on which the human spirit rises to the contemplation of truth; and God has placed in the human heart a desire to know the truth - in a word, to know himself" Pope John Paul II (Encyclical Letter fides et ratio of the Supreme Pontiff John Paul II To the bishops of the Catholic church On the relationship between faith and reason September 14, 1998) "When I think about God. I can't prove God. I can't put God in a test tube. I can't put him on a computer screen. But that doesn't mean he's not real." Rev. Billy Graham (speech at Qualcomm Stadium, San Diego - May 9-11, 2003)

9 1800 s: there was a scientific debate about evolution vs creation. Evidence (next topic) led to evolution being accepted via scientific standards. Today: creationism is based on faith, not data, so it is not a scientific idea and therefore not accepted within the scientific community. (note: this doesn't mean that it is false, merely unscientific) What does that mean for this course? This is a science course, not a religion or philosophy course, so we summarize the evidence for evolution and develop the science.