Biological Anthropology the nature of science

Some Terms used in Science Hypothesis: a statement developed to explain a phenomenon – must be testable/potentially falsifiable Data: the evidence that helps assess a hypothesis Empirical: derived from observations/experiments Theory: a set of explanatory principles (hypotheses) that have not (yet) been falsified

Science is … a process that develops provisional truths That is, “truths” that may one day be replaced by better “truths”

Science is not… a process that develops absolute truths That is, TRUTHS that may not be questioned and can never be corrected or improved upon

Two Assumptions of Science 1)You explain natural phenomena only by referring to other natural phenomena Methodological materialism 2) If two models both explain the data, use the simplest (unless you have a reason not to) OCCAM’S RAZOR (this is NOT the same as Philosophical Materialism)

Science can be understood as a process of “modeling” reality reality

A Theory Emerges the first model does not explain some aspects of its focus predicts outcomes that will not occur x + 1 = y

Science Advances a second, “better” model unexplained phenomena predicted, but not “real” x 2 + 2z = 0

Comprehension Increases another, even “better” model predicted, but not “real” unexplained phenomena

Science as the Quest for ever “better” models

Is there a “perfect” model? explains all phenomena that do exist predicts nothing that does not exist

Not yet…

Science as a revolutionary process “normal” science anomalies scientific “revolution” A “Paradigm Shift”

The Copernican Revolution the shift from a geocentric (“earth-centered”) to a heliocentric (“sun-centered”) model of the solar system

An Immobile Earth All celestial objects move around the earth the heavens are perfect, the earth imperfect these greek Ideas are adopted by Christian thinkers The Human drama is the reason for creation Earth is “center stage” Challenging the geocentric view is heresy

Nicholas Copernicus Physician, lawyer, church administrator De Revolutionibus Orbium Coelestium (“On the Revolutions of the Celestial Orbs”) published in 1543

Heliocentric Worldview the planets all move in a similar manner Heliocentrism makes fewer assumptions has greater applicability the movements of celestial objects can be explained and predicted Retrograde Mars (and Uranus) Credit & Copyright: Tunc Tezel

But acceptance was slow, as heliocentrism seemed absurd If the earth is moving, how can a stone that is thrown straight up come straight down? If the earth is a planet, why is it the only one with a moon? If the earth did move, why did the relative positions of the stars not (why would space be that big?)

Galileo Galilei Born 1564 Begins studies at University of Pisa in – appointed professor of mathematics at University of Padua

Galileo Galilei 1609 – makes his first telescope Discovers Sunspots Rings of Saturn Phases of Venus Satellites of Jupiter Galileo’s notes of his observations of Jupiter and its moons; January 1610

Galileo Galilei Dialogue Concerning the Two Chief World Systems (1633) Condemned by the Roman Inquisition in 1633 Under house arrest from 1633 until his death in 1642

Science as a revolutionary process “normal” science – sun goes around earth anomalies – planetos the “revolution” – earth goes around sun

Another Scientific Revolution Antoni van Leeuwenhoek ( ) Some of van Leeuwenhoek’ instruments (replicas)

The first image of microbes (1683) (the dotted line between C and D indicates motility) Spermatozoa by van Leeuwenhoek originally published in Philosophical Transactions,

Van Leeuwenhoek’s Work would ultimately lead to Robert Koch ( ) Louis Pasteur ( ) Joseph Lister ( ) the discovery that microscopic organisms can cause illness and death

Things to remember Scientific discovery is driven by the community of scientists, who actively look for problems with theories Scientific discoveries may contradict cherished notions of what the world is like Scientific truths are provisional, as better models are continually being pursued Science is a self-correcting process

Science takes place in a Social Context This textbook contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things. This material should be approached with an open mind, studied carefully, and critically considered. Approved by the Cobb County Board of Education Thursday, March 28, 2002