14 JANUARY 201423_BIO130_0114141/14/2014Bio 130 Lecture 2 TR 12:40-1:55pDr. Sarah Dalrymple, Office Hours TR 2:30-4:30pm Dabney 657B, or by appointment- New mastering biology code is needed to submit homework assignments- First homework due Mon, Jan 20th at 11:59p, Optional Intro to MB- Quiz one week from today- Lecture slides and review questions posted on Blackboard after class- Homework always listed on last slide in case of absence- Clicker needed in class on Thursday- Do readings and homework before class- Second Exam rescheduled on March 27, voted in classIntroduction and Review of BiodiversityObjectives: Define biodiversity, identify variables, interpret graphs, and explain causation versus correlation Biodiversity can be measures as genetic, species or ecosystem diversity- Species diversity combines species evenness (abundance of each species relative to the others) and richness (number of unique species)- How many species are living today? 1.5 million named species, estimated 10-100 million species- Species diversity increases by evolution, decreases through extinction.- A species is a group of organisms that share many essential characteristics, including the ability to mate. Two individuals from the same species will have similar DNA sequences when contrasted against other species.Graphical Analysis- Latitudinal gradient in species richness.Independent variable: latitude Dependent: number of speciesData collected along the same longitudinal line Graphed on a scatterplot to show trends and gradient- When intrepreting observed data without experiments, the variables can be correlated but are not nessesarily cause and effect.- Species richness’ affect on net primary productivity, NPP (rate at which plants generate biomass)Hypothesis: NPP increases with increasing species richnessNull Hypothesis: Increasing species richness has no effect on NPPIndependent: Number of speciesDependant: NPPGraph: Scatterplot with line of best fit- Causation is a cause and affect- Correlation is just a trend in the relationship between two variables.- Since species richness increases productivity of biomass, it would be beneficial to grow more than one type of plant grown together on a farm. Effect of crop diversity on yield:14 JANUARY 2014Independent: Number of cover cropsDependant: crop yieldBars with different letters are statistically different from each other (p<0.05)- How biological systems change over time. (climate change)Temperature increases with fluxuation over