Transcript 7/8
•Exam #3 W 7/9 in class (don’t forget your cheat sheet) •Bonus #2 due 7/10 in class •Yes, discussions on Wed, 7/9 •Class on Th 7/10 will be a review for the optional FINAL EXAM •Final Sat. 7/12 at 7-10pm emester Two ways to think about the world: Reductionism atoms molecules organelles cells tissues organs systems organisms holism environment Emergent properties- properties of an organism or group that none of the individual components possess. From: “Emergence” by Steven Johnson (2001) Plant can integrate information and make decisions without a central nervous system. Plants respond to touch CB 39.26 Plants respond to touch CB 39.26 touched not touched Shade Avoidance direct light shade Plant can integrate information and make decisions without a central nervous system. CB 39.26 Light vs Touch CB 36.2 Water travels from ground out through stomata via xylem Stomata control entry of CO2 and exit of H2O from plant leaves CB 36.12 Stomata Stomata on the underside of a leaf Plant can integrate information and make decisions without a central nervous system. Stomata aperture is affected by many stimuli: light, water, temperature, sugar content, circadian rhythm, CO2 levels… CB 36.14 Slime mold aggregation Slime mold aggregation It has been known for some time that slime mold aggregation occurs via cAMP signaling It was assumed that certain cells (pacemakers) signaled the others to aggregate But, no one could find the pacemakers single cell Each cell releases cAMP and responds to local conditions. Cells follow cAMP trail to aggregate with other cells. cAMP cAMP single cells cAMP cAMP cAMP cAMP cAMP cAMP cAMP cAMP cAMP Each cell releases cAMP and responds to local conditions. Cells follow cAMP trail to aggregate with other cells… self-organizing cAMP cAMP single cells cAMP cAMP cAMP cAMP cAMP cAMP cAMP cAMP cAMP Slime molds can learn. The plasmodium can figure out the shortest path through a maze. http://www.abc.net.au/science/news/stories/s189608.htm Ant colonies: this is our concept of how an ant colony is organized. Queen is fed and lays eggs, but gives no orders. http://www.antstop.co.uk/nests/nest-static.jpg So who is in charge? Ant midden, garbage, and cemetery are put far away from colony and each other. Can do this without central command. With a few simple criteria, the plan comes together. Cities: Before zoning regulations were self-organizing. Different zones: industrial, residential, markets, arts, etc. Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response. CB 48.3 Response CB 48.5 Nervous systems can make complex calculations with cells that are on/off (1 or 0) CB 48.27 There is no boss in the brain. Nor directions in how to make one. Much of our society is based on emergent properties. Much of our society is based on emergent properties. Problems can arise as individuals try to manipulate the system. Much of our society is based on emergent properties. Problems can arise as individuals try to manipulate the system. Google Bombs: Miserable failure directed searchers to the White House biography of G.W. Bush. http://news.bbc.co.uk/2/hi/americas/3298443.stm Much of our society is based on emergent properties: Democracy- as a group can we make better decisions than an individual? •Exam #3 W 7/9 in class (don’t forget your cheat sheet) •Bonus #2 due 7/10 in class •Yes, discussions on Wed, 7/9 •Class on Th 7/10 will be a review for the optional FINAL EXAM •Final Sat. 7/12 at 7-10pm emester