BIOL 102 HUMANS in NATURE

BIOL 102 HUMANS in NATURE Spring 2010 Neil Greenberg O

DETERMINISM A belief that everything has a cause, and that a specific cause leads to a specific effect – if analyzing a phenomenon doe not reveal causal relationships, look deeper!

DETERMINISM A belief that everything has a cause, and that a specific cause leads to a specific effect

DETERMINISM NATURE NURTURE • FIXED • BIOLOGY • GENETIC • ENSLAVED by nature • “we are survival machines, programmed by selfish molecules called genes” (Dawkins 1975) • FLEXIBLE • CULTURE • ENVIRONMENT • LIBERATED from nature • “… give me a dozen healthy infants” (Watson 1925) EPIGENESIS: the progressive reciprocal interactions between genes and their environments

Epigeneticsrefers to changes in phenotype (manifest effects of genes that natural selection acts upon) WITHOUT changes in the underlying genotype. These changes may remain through cell divisions for the remainder of the cell's life and may also last for multiple generations. Rather than change in the underlying DNA sequence of the organism, environmental factors inhibit or enable the genes to "express themselves”

POWER … FREEDOM But too much success is a dangerous thing … We are, after all, humans. (control relieves stress, evokes “pleasure.”) SCIENCE emphasizes learning cause-and-effect relationships , enabling predictions about the outcomes of some possible circumstance. And by controlling these circumstances we may find ourselves with immense power. We become FREE of the limitations with which we were born. [what are the limits of such freedom?]

SUCCESS in controlling nature can be a dangerous thing … We are, after all, humans. Power is very addictive, but more likely we are born with an instinct to control: … first ourselves, then everything!

The mental operations are the same in infants as in scientists:

Here is a good way to think about science: “It is neither a philosophy or a belief system. It is a combination of mental operations that has become increasingly the habit of educated peoples, a culture of illuminations hit upon by a fortunate turn of history that yielded the most effective way of learning about the real world ever conceived.” --- E.O. Wilson, 1998

The mental operations are (at their core) the same in scientists as in infants: • TEST YOUR FACTS: are they REAL? Are they VALID? Do your perceptions CORRESPOND to the real world? • TEST THEIR COHERENCE: do they FIT IN in with everything else you know? Do they help tell a story? Do they improve or change the story?

FREEDOM? • Whatever motivates an infant to learn about itself and its environment (curiosity, exploration) ... what is learned enables the infant (then child, then adult) to better meet its emerging NEEDS. • Growing knowledge effectively LIBERATES the infant from the limitations it were born with, the environment we were born into? • Does this really change as WE also seek knowledge • Sir Francis Bacon famously said “Knowledge is Power”

But what infants or scientists DO with their facts can be very variable. People have different “ways of knowing,” and different ways of testing or expressing their knowledge.

Testing and expression of beliefs is part of learning ... infants, and artists, scientists, scholars, and citizens TEST and EXPRESS BELIEFS ... They enlarge and enrich their knowledge to the extent that it is “cost effective” to do so.

DIFFICULTIES of DETERMINISM • How complex are the chains of cause and consequence? • chains of causes may be at different layers or levels of organization (animal cell, organism, society, galaxy) consequences, and studied in different ways • How do chains of causation INTERACT with each other • CONSEQUENCES that could not be predicetd even if you know about all possible CAUSES are called EMERGENT.

An artist’s view of successive “layers” in nature Crystal WagnerUT graduate student

An artist’s view of successive “layers” in nature Pavel Tchelitchew “Hide-and-Seek”

A mechanical view of successive “layers” in nature Clockwork model of solar system

A physiologist’s view of successive “layers” in nature connectionist model of autonomic biological functions

A neurophysiologist’s view of successive “layers” in nature

PROXIMATE & ULTIMATE CAUSES & CONSEQUENCES Depending on the effect of interest, there can be along chain of causation .. And some relevant elements may be more or less immediately involved with the effect

The “interactome” (molecular interactions in a cell) CONNECTIONS provide thefirst clues about chains of causes are obtained by mapping all known connections.

Not only is knowledge fragmentary because it is incomplete but it is necessarily fragmentary because of the fundamental nature of an organism. Wendell Berry from The Larger Circle

All creatures ... dance ... To a music so humble and vast that no ear hears it except in fragments. Wendell Berry from The Larger Circle

The “central dogma” of biology is the best known chain of causation: genes to traits

EPIGENETICS • Genome (all the genes) • Epigenome (all the reactions between the gene and the manifest trait) • Phenome (the organism: the manifest traits: THIS is what be more or less effective in the evolutionary landscape) • Genes enabled or disabled from expression by methylation (the ordly progression of epigenetic events is the key to DEVELOPMENT : the kinds of cells that differentiate and their levels of activity.

Epigeneticsrefers to changes in phenotype (manifest effects of genes that natural selection acts upon) WITHOUT changes in the underlying genotype. These changes may remain through cell divisions for the remainder of the cell's life and may also last for multiple generations. Rather than change in the underlying DNA sequence of the organism, environmental factors inhibit or enable the genes to "express themselves”

BIOL 102 HUMANS in NATURE