User:Isabella Jorgensen/Notebook/Biology 210 at AU

January 25, 2015 Biological Life at AU

Introduction

The purpose of this experiment was to collect different forms of life from different ecosystems on AU's campus and to observe the biodiversity within each transect. The reason each student was to observe different ecosystems on campus was to give them a general idea of how biodiversity works on a small scale so that they could apply what they learned to a larger scale. The study of ecology, which focuses on how different organisms and species relate to one another is the overarching theme for this experiment as each transect represents a small ecosystem in which the biotic and abiotic organisms are unique to their location in time and space. To examine the effects of evolution, the students observed several members of the green algae group in the Volvocine line. Through observations they were looking to observe the workings of natural selection and the three main mechanisms, variability, heritability, and differential capacity for survival and reproduction. 

Materials and Methods

To perform the first half of this experiment three different members of the Volvocine line, Chlamydomonas, Gonium, and Volvox were needed to view under the microscope. Each student then had to count the number of each type of cell, calculate the size of the colony, determine whether is was isogamous or oogamous (isogamy is sexual reproduction of like gamete while oogomy is sexual reproduction of unlike gametes), determine the specialization and mechanisms of each cell, and to draw a picture of them. For the second part of the experiment the students were placed in groups of three and were assigned transects of the dimensions 20 by 20 meters in different parts of the AU campus. Following each group was to take note of the transects topography and location. The groups were also to draw an ariel view of the transect, labeling it thoroughly including north, south, east and west. The students were each given a 50 mL conical tube to collect a soil sample as well. Once back in the lab each group made a Hay Infusion culture with their soil samples. To make the Hay Infusion each student had to place 10-12 grams of soil into a plastic jar with 500 mLs of deerpark water. Following, they had to add 0.1 gm of dried milk. Once this was added they had to gently mix the contents of the jar and clearly label the jars lid.

Results

The first picture depicts the ariel view of the transect. The general descriptions of the topography and location were also included in this picture. The second image is of the Volvocine Table, which includes all of the observations made about the three members of the Volvocine family.

Conclusion

While the two components to this experiment differed greatly they were shared the central theme of evolution. While the transect/hay infusion do not directly correlate with evolution, the study of the bacteria within these transects gives a better look into what evolutionary steps were taken. Studying the three volvocine members before extracting the soil samples and conducting the hay infusion was useful in gaining a background understanding of the three members were related to each other, how they differed, and how evolution is what lead to these differences. IJ

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