How evolutionary analysis results in bowfins show species diversity and lineages of a ‘living fossil’

Phylogenomic analysis of the bowfin (Amia calva) reveals unrecognized species diversity in a living fossil lineage

Summarized by Colton Conrad, a proud geology major at the University of South Florida. He is a senior who is as a geologist at ASRus (Aquifer Storage Recovery). Colton’s life revolves around fishing, hunting, exercising, and creating things out of metal. He is a great taxidermist and a fine creator of swords and shields.

Hypothesis: The purpose of this paper is to categorize bowfins into evolutionary groups by collecting samples to determine their diversity and evolutionary history.

Data: The data here is a collection from 94 individual bowfins found from the eastern United States. From phylogenetic analysis, which is a way of understanding species evolution from genetic data, the researchers involved with this project were able to find and sort out genetic variations in the DNA of the bowfin known as SNPs (single nucleotide polymer) to determine which species were most closely related. The sorting of SNPs is finding nucleotides that have changed but are still found in the population. They used specific lengths of DNA to define changes in the four nucleotides (adenine, cytosine, guanine, and thymine (A, C, G, and T)) in bowfin lineages and to find diversity among the population. 

Methods: Scientists ran the data using evolutionary tree computer programs to find the most supported configurations of bowfin relationships. Figure 1 shows the evolutionary reconstructions and the genomes from bowfins after comparing the phylogenetic population structure in bowfins. The researchers also ran a bootstrap analysis to test the likelihood of their results. Bootstrapping means that the analysis is re-run multiple times and the number of times the original answers are returned is counted as a percentage (e.g., the bootstrap support is 100% when the same tree structure is returned 100 times). 

Figure one is a circular chart showing the relations and patterns in the bowfin as an evolutionary tree. The four different colors red, blue, green, and yellow show the different species clusters. The larger dots colored green represents 100% bootstrapping, and the descending gray dots represent the percentage getting lower.


Results: The results of this study have revealed species diversity of bowfins populations (Figure 2). By analyzing SNP of the bowfins from all the locations the study revealed diversity in the population by showing the molecular and genetic data collected from these species can be traced back to two species of prehistoric fossil bowfins. This means that at least two bowfin species from this study are quite similar to the fossil forms and are considered ‘living fossils’

Why this study is important? This study is important because it gives us insight into what prehistoric fish species were like and how other species may have evolved to give us the diversity we see today. 

Broader Implications beyond this study: This study has added an deeper perspective to the DNA variations found in bowfin to help understand evolutionary adaptations found in soft ray fined fish, helping in our understanding of modern fish and terrestrial species. 

Figure two is a picture of the diversity of bowfins collected from the study. The bowfins in this figure vary in color based on environmental surroundings. Species A is a lighter brown color with reddish fins and a white belly. Species B is darker brown with a tan belly. Finally, species C is a blackish green color with a lime-colored belly. The fins, gills, and body types are all the same. The dorsal fins of the bowfin are a long soft ray design with a large, rounded tail. The pectoral fins are small compared to the body’s size and are rounded shape much like the other fins. This image shows what a bowfin looks like and gives a visual into the diversity of bowfin.

Citation: Wright, J., Bruce, S., Sinopoli, D., Palumbo, J., & Stewart, D. (2022). Phylogenomic analysis of the bowfin (Amia calva) reveals unrecognized species diversity in a living fossil lineage. Scientific Reports, 12, 1–10.