Evolutionary Laboratory, Lab Report Example

Abstract

Agglutination of antiserum was tested in order to evaluate for evolutionary relationship between different species. Human antiserum mixed with human blood results in clumping or agglutination.  In order to test the similarity of species, the use of human antiserum using the Nutall experiment was tested against three species: chimpanzee, cow, and frog. The results of the experiment illustrated that the human sample resulted in the agglutination of four wells, as predicted.  In addition, the chimpanzee showed agglutination in one cell suggesting similarity to human blood. Further research using DNA techniques can allow scientists to test specific genes in both the human and chimpanzee to further correlate an evolutionary relationship.

Introduction

Previously, evolutionary relationships were compared between species from physical characteristics, such as physical appearance.  For instance, Humans (Homo sapiens) and chimpanzees (Pan troglodytes) were analyzed structurally through correlations with skull structure. With recent advances in DNA techniques, genetic data has shown that humans and chimpanzees shared a common ancestor approximately 5-7 million years ago. (Varki and Altheide, 2005). There are additional methods that can illustrate a correlation in similarities between different species, such as through the use of antiserum and agglutination methods. In the current laboratory, antiserum of different animal’s species was tested in order to evaluate for evolutionary relationship between species. Human antiserum mixed with human blood results in clumping or agglutination. This allows scientist to compare the amount of clumping between different animal species using human antiserum in order to suggest an evolutionary relationship.  It is expected that when human antiserum is mixed with monkey blood, the antibodies in the serum will recognize the blood and react causing clumping.  It is therefore hypothesized that humans will be more closely related to a chimpanzee than the other selected animals species, such as a cow and frog.

Materials and Methods

A 24-well plate was labeled with six rows for each of the animal’s species.  Simulated blood samples from a human, cow, chimpanzee and frog were obtained and placed in each well using a micropipette and volumes observed in Table 1.  400µL of anti-human serum was then added using a pipet to each of the wells.  The wells were stirred gently with a clean toothpick. The wells were observed for two minutes for agglutination reactions and results were recorded.

Results

The results of the experiment illustrated that the human sample resulted in the agglutination of four wells.  Agglutination also occurred in one well of the chimpanzee sample.  (Table 2)  No agglutination occurred in the cow or frog samples.  (Table 2)

Discussion         

The Nutall experiment illustrated a relationship between the human and chimpanzee serum.  It was expected that agglutination would occur in the human blood since human anti-serum was being placed into the wells.  The chimpanzee, as hypothesized, showed some agglutination in one of the wells, indicating similarities between the chimpanzee and human blood.

The Nutall experiment allows scientists to observe a connection between species in regard to an evolutionary relationship.  Additional studies, such as DNA sequencing should be studied in order to determine the actual relationship.  For instance, the human genome project can identify specific markers in the human DNA, which can provide information about human origins.  DNA sequencing of related species, such as chimpanzees, can therefore allow the ability of scientists to compare genes among possibly related species.

References

Varki, A. and Altheide, T.K.  (2005).  Comparing the human and chimpanzee genomes: Searching for needles in a haystack.  Genome Res. 15:1746-1758.