BIOC51H3 Lecture 5: BGYB51H3 Lecture 5 Notes Sep 24
11 Aug 2010
School
Department
Course
Professor
BGYB51H3 Lecture 5 Notes
-in experiment with snails, no difference in survivorship with no crabs
-with crabs, thicker shell snails have a higher survivorship
-crabs impose natural selection on shell thickness of snails
-an allele can cause higher blood saturation content than the average
-individuals with higher blood saturation have decreased mortality in Tibet
-strong natural selection on traits in humans that are heritable
-patterns are broad scales of different taxon and involve macroevolution
-processes involve microevolution and can lead to macroevolution changes
-microevolution involves changes in populations across a few generations due to changes in
gene frequencies
-macroevolution involves the study of large phenotypic change and phylogenetic patterns over
long periods using comparative method or fossil record
-scientific method involving experiments (natural or planned) and/or observational studies is
used to analyze microevolution
-microevolution involves a shorter time period involving changes in allele frequencies
-macroevolution involves a longer time period involving changes across taxon
-in experiments, there will be a distribution of responses that occur as a result of manipulation
-distribution of responses must be compared through treatment groups
-a strong test involves opposing predictions of a few alternative hypotheses
-statistical test measures if the observed difference is due to chance
-magnitude of difference and sample size affect how likely the result is due to chance
-increased sample sizes will more likely result in data that has not occurred due to chance
-the smaller the P-value the greater the effect of X on Y
-observation test involves careful measurement of one variable and how it relates to another
variable
-planned experiment involves independent variable manipulated by researcher
-natural experiment involves independent variable manipulated naturally (e.g. crab
experiment)
-in experimenting, one must control for possible confounding factors and sample sizes are
important
-experimentation involves comparing treatment groups to control groups to reject or fail to
reject the null hypothesis
-alternative hypotheses strengthen tests while null hypothesis is still considered
(refer to pg 366-369)
www.notesolution.com
Document Summary
In experiment with snails, no difference in survivorship with no crabs. With crabs, thicker shell snails have a higher survivorship. Crabs impose natural selection on shell thickness of snails. An allele can cause higher blood saturation content than the average. Individuals with higher blood saturation have decreased mortality in tibet. Strong natural selection on traits in humans that are heritable. Patterns are broad scales of different taxon and involve macroevolution. Processes involve microevolution and can lead to macroevolution changes. Microevolution involves changes in populations across a few generations due to changes in gene frequencies. Macroevolution involves the study of large phenotypic change and phylogenetic patterns over long periods using comparative method or fossil record. Scientific method involving experiments (natural or planned) and/or observational studies is used to analyze microevolution. Microevolution involves a shorter time period involving changes in allele frequencies. Macroevolution involves a longer time period involving changes across taxon.
