Studying Spider Biodiversity

Like all other creatures the live on earth, spiders are also very interesting research subjects. These arachnids have exploited almost all types of niches throughout the entire planet. Their ability to adapt to their environment and to develop characteristics that will enable them to survive in each of these environments make spiders very useful indicators of the changes experienced by our environment. Thus, studying spiders enable experts and researchers to explore the different concepts of biological diversity on our planet and at the same time, provide useful practical data on the application of these concepts to the steps that we take in conserving environmental biodiversity. People behind these studies usually proceed with their researches in three levels, each increasing in depth as the one before it. These levels are: 1. Sorting and Classifying, 2. Contrasting and 3. Evolutionary Comparison. This article will discuss about the first level in length. However, for levels 2 and 3, all that this article can offer is an overview.

1. Sorting and Classifying

A comprehensive spider study involves different spider subjects or a collection of different spiders. Spiders might be grouped according to the environment that they are found or to different characteristics. In is very important for researchers to develop and effective and efficient way to sort and classify spider collections in order to assess fully if the data is comprehensive enough to make the study rich and realistic.

But how do researchers collect spiders? Oftentimes, the more equipped researchers are the biologists because they are highly trained professionals who know how to handle different types of creatures, including spiders. First, biologists would choose a range for their sampling. So, if the sample range is 100, they would have to find 100 spiders from 100 different trees, if the test environment is a forest. Collected spiders should not be deformed in any way and almost every time, biologists would simply dislodge a live spider to drown in a vial of alcohol. The alcohol will serve as a preservative of the spider's body. Each spider collected will be examined in the laboratory to determine whatever data that the biologist would need from the spider. These spiders are photographed using a microscopic camera and the photos will be compiled along with a detailed description of the spider.

Now that each of the spiders have been identified, the biologist would have to sort these spiders one by one. Normally, biologists sort spider based on their specie but of course, in some cases, biologists may opt to sort them some other way. To get accurate information about the spider, it has to be inspected based on its external characteristics. This task will be easier now because all that the biologists have to sort are the photographs along with their descriptions. This task would have been harder if the biologist have to sort dead spiders. This is also the importance why they have to preserve the spiders, carefully examine them in the laboratory and take clear microscopic shots of their preserved bodies. Biologists use tables and graphs to assist them in classifying spiders based on specie. Examining the spider's genital is often the easiest way to quickly identify which specie a spider belongs to.

Now that the spiders have been classified based on specie, the biologist would have to assign each specie-group with a "friendly name". The name will help the biologist and the other researchers to refer to specie with description names that would easily relate the spider specie into an image in their minds. This is extremely helpful to research groups where there are many people working on the same research.

To be able to know if the collection does represent the real spider diversity in the test environment, the data gathered should meet certain standards. For example, the biologist has to construct a Collector's Curve which plots the cumulative number of spider species versus the number of spider species found in the place. The curve was developed by Colwell and Coddington in 1994. According to the two, sampling cannot stop while the curve is still increasing. Thus, if this happens, it only proves that the sampling is yet incomplete. Furthermore, if the curve flattens out, then all the species have been detected.

The collector's curve is constructed by using random specimen data within the spider collection. The process is rather too technical for a lay person to understand, but to put it simply, each point in the graph shall represent one random sample from the collection. The graph will progress for each sample which has been randomly picked up until the entire plot is completed, that is, all X and Y coordinates have been filled up. The resulting graph would either be flat, steep, slow rising or slow falling. The shape of the curve actually determines the diversity of the spiders in the test environment. Biologists are trained to interpret such graphs to give understandable conclusions to a lay person.

2. Contrasting

The real goal of level 2 is to contrast the diversity of spiders in the test environment with the diversities of the environments where conservation efforts are in place. To do this, biologists will compare the collection that that they have obtained in their test environment with the data that that has been obtained in conserved environments. These data might have been obtained by other biologists and researchers, so the members of the research team also need time to understand the data before it can be compared to theirs. In order to do that, they need to follow mathematical and statistical formulas to establish a common ground. Once the calculations have been completed, researchers will be able to answer questions like "how does the test environment rank among protected environments", "how will the protection be performed” and so much more.

3. Evolutionary Comparison

Now, this level is rather more interesting to an average reasonable person because it explores the distinctiveness of each spider specie from the others based on the spider evolution. That is, biologists will have to consider that at one point in time, spiders belonging to different spider species might have evolved from the same species.