Notes - [Thesearethefirstnotesfromthebehaviorlectures]

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[These are the first notes from the behavior lectures] Text :  Chapter 25 of Audesirk, Audesirk and Byers.  Please note: the lectures on behavior will  take an entirely different approach than that taken by these authors.  Much of the  information in Chapter 25 will be covered in lecture but combined with a lot of other  information and organized quite differently.  When in doubt about a fact or subject, rely on  this outline and the lectures rather than the text.  But there are some terms and concepts  presented in the text that are not covered in lecture and you are responsible for them. Lectures 3/24/09: Tuesday- lecture 1 I.  Behavior as an adaptive trait .   o Circadian rhythms (about 24 hours) o Circannual rhythms ( less than 365 days) o Tidal rhythms (about 12.4) o Lunar rhythms (about 13 per year)   A. To illustrate the adaptiveness of a behavior, we will look at circadian rhythms and  the biological clocks that regulate them (circa = about; dia = a day; i.e., rhythms of about, but  not precisely, 24 hours).   Rhythms don’t just have to do with sleep; they are all over and involved in all life forms Circadian Rhythms: An Example of a Clock-Controlled Circadian Rhythm The Sleep/Wake Cycle of Flying Squirrels; they become active as the day and night fluctuate. [nocturnal animals] The entrained cycle that look away the aspect of the clock gave proof that  they were using a biological clock running a life cycle, its just not set at 24- hours.  What’s adaptive about having a rhythm regulated by a clock? o What’s adaptive about having a circadian clock that runs faster  or slower than 24 hours and this must be rest everyday. 1.  Almost all biological processes exhibit circadian rhythmicity (e.g., leaf  movements in plants, sleep/wake patterns in people, sensitivity of animals and people to  drugs, the secretion of hormones in humans and animals, etc.). 2.  Most of these rhythms are clock-driven.  No one yet has discovered the  nature of the clock mechanism, but scientists are getting close and whoever does make this  discovery will get a Nobel Prize. Mechanisms: thesuprachiasmatic nucleus (SCN)in the brain. o How? The concentration of melatonin in the brain helps the organism determine whether it is nighttime. [ Increases at night and make you tired] Other Rhythm Phenomena Interest in Humans
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o Humans are run by a light-dark cycle. Owls vs. larks (mutation found in mice)
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This note was uploaded on 02/19/2010 for the course BIO 301 L taught by Professor Fritz during the Spring '09 term at University of Texas at Austin.

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Notes - [Thesearethefirstnotesfromthebehaviorlectures]

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