Mathematics for the Biosciences at Farmingdale State Sheldon Gordon gordonsp@farmingdale.edu Major Premise “Biology will do for mathematics in the twenty-first century what physics did for mathematics in the twentieth century” Major Premise Almost all math and bio projects start at the calculus level or above. But the overwhelming majority of beginning biology students, both majors and non-majors, typically are at the college algebra or precalculus level. Most of these students have avoided math as much as possible. Our Project Our original plan was to begin developing the first stages of a new mathematics curriculum to serve the needs of biology students, both the bioscience majors and the non-majors. This would also impact the level of quantitative work in the biology courses. Our Project The project is a collaborative effort between Farmingdale State University and Suffolk Community College. Farmingdale State brings an exceptional history of successful efforts in reforming the mathematics curriculum. Suffolk brings an outstanding record of utilizing technology and quantitative methods in its introduction biology courses and labs. The Farmingdale State Project Our first step was to develop an alternative to our modeling-based precalculus course that would focus almost exclusively on biological applications. The course would feature a lab component taught by the biology faculty, so that each week’s primary math topic would be accompanied by an experiment requiring the use of that mathematical method. Course Topics Week 1 Behavior of Functions Week 2 Families of Functions, Linear Functions Week 3 Linear Functions and Linear Regression Week 4 Exponential Growth and Decay Functions Week 5 Exponential Regression and Power Functions Week 6 Power Functions and Polynomials Intro to Measurements and Measuring Linear Growth – part 1 Linear Growth – part 2 Exponential Growth Exponential Decay part 1 Exponential Decay – part 2 Course Topics Week 7 Week 8 Week 9 Week 10 Week 11 Week 12 Week 13 New functions from Old Logistic and Surge Functions Matrix Models and Linear Systems Sinusoidal Functions and Periodic Behavior Periodic Functions – part 2 Probability Models Probability Models and Difference Equations Power Function growth Logarithmic Functions Logistic Growth Surge Functions Polynomial growth Periodic Behavior Probability Model (genetics) What Happened Next To accommodate the lab component, we had to change the precalculus course from four to five credits. Because of that and conflicts with other courses (intro chemistry), the biology students did not register for the course and it did not run. What We’ve Done Instead All the labs in the introductory biology course are in the process of being changed to dramatically increase the level of quantitative experience – the new labs will incorporate most of the labs intended to be part of the precalculus course. The math department has officially created a new four credit precalculus course to serve the needs of the biology students – the same math course, but no lab. What We’ve Done Instead The math department has created a new two-semester calculus sequence for biology students – it will emphasize concepts over manipulation and will stress biological applications. The math department has created a onesemester post-precalculus mathematical modeling in the biological sciences course for bioscience majors and applied math majors. Some Sample Problems Identify each of the following functions (a) - (n) as linear, exponential, logarithmic, or power. In each case, explain your reasoning. (m) (g) y = 1.05x (h) y = x1.05 x y (n) x y 0 0 3 5 1 (i) y = (0.7)t (j) y = v0.7 1 (l) 3U – 5V = 14 7 2 2 (k) z = L(-½) 5.1 7.2 9.8 3 3 9.3 13.7 Some Sample Problems Biologists have long observed that the larger the area of a region, the more species live there. The relationship is best modeled by a power function. Puerto Rico has 40 species of amphibians and reptiles on 3459 square miles and Hispaniola (Haiti and the Dominican Republic) has 84 species on 29,418 square miles. (a) Determine a power function that relates the number of species of reptiles and amphibians on a Caribbean island to its area. (b) Use the relationship to predict the number of species of reptiles and amphibians on Cuba, which measures 44,218 square miles. Island Area N Redonda 1 3 Saba 4 5 Montserrat 40 9 Puerto Rico 3459 40 Jamaica 4411 39 Hispaniola 29418 84 Cuba 44218 76 Number of Species The accompanying table and associated scatterplot give some data on the area (in square miles) of various Caribbean islands and estimates on the number species of amphibians and reptiles living on each. 100 80 60 40 20 0 0 15000 30000 Area (square miles) 45000 (a) Which variable is the independent variable and which is the dependent variable? (b) The overall pattern in the data suggests either a power function with a positive power p < 1 or a logarithmic function, both of which are increasing and concave down. Explain why a power function is the better model to use for this data. (c) Find the power function that models the relationship between the number of species, N, living on one of these islands and the area, A, of the island and find the correlation coefficient. (d) What are some reasonable values that you can use for the domain and range of this function? (e) The area of Barbados is 166 square miles. Estimate the number of species of amphibians and reptiles living there. The ocean temperature near New York as a function of the day of the year varies between 36F and 74F. Assume the water is coldest on the 40th day and warmest on the 224th. (a) Sketch the graph of the water temperature as a function of time over a three year time span. (b) Write a formula for a sinusoidal function that models the temperature over the course of a year. (c) What are the domain and range for this function? (d) What are the amplitude, vertical shift, period, frequency, and phase shift of this function? (e) Estimate the water temperature on March 15. (f) What are all the dates on which the water temperature is most likely 60?