Jul 21, 2019 | Updated: 08:54 AM EDT

A sharks' tooth from its victim lead to the disentanglement of a 24-yr old case

Jul 13, 2019 06:52 AM EDT

(Photo : Pixabay)

Shark attacks had been one of the common animal attack cases that United States citizens had been facing. Some victims died while some survived. It is such a miracle if you survive with a complete pair of hand and foot. Before, it is impossible to know what kind of shark had attacked the victim but as of now with the continuing development of technology, the attacker can be determined which was made possible by a shark attack case back in 1994.

In 1994 on the Flagler Beach in Palm Coast Florida, a 21-year-old surfer Jeff Weakley was attacked by a shark and luckily survived with lacerations. For 24 years after the said event, Jeff had been fascinated by the thought of what kind of shark attacked him until he read an article that eventually gave him the answers he was looking for.

The research team led by Gavin Naylor, Ph.D., who is also the director of the Florida Program for Shark Research (FPSR) at the Florida Museum of Natural History, identified the species of shark that bitten a child off the coast of Fire Island in 2018. Jeff searched and tracked the team to finally help him to identify his attacker by the tooth fragment that he tweezed out from his foot. "I am curious to see if they could use the same DNA process on my sample," said Weakley on Inverse.

"We all thought that because the tooth had been in Jeff's body for so long that there was almost no chance of retrieving any of the shark's DNA," Naylor said. "However, we all also thought that it would be fun to try!"

In their test, the lead author of the new study and lab manager in FPSR Lei Yang, Ph.D., thought that the project will be difficult and may take time since there is a possibility that the DNA might not be totally extracted given that it may be already degraded by Jeff's immune system. Unexpectedly the opposite happened. After cleaning the tooth fragment and scraping its pulp, the experiment had been successfully delivered.

According to Naylor, their team uses the technique for estimating evolutionary relationships among the different species of sharks, which includes understanding the population structure and historical demography, the same way certain companies like 23 & Me done for humans. The technique was previously tested in the century old specimens of archival river sharks; however, the test was done using preserved fragments in museum.

The results showed that the attacked was by Carcharhinus limbatus or commonly known as the blacktip shark. The team was not certain of the results at first, in fact, they thought the sample was contaminated however the DNA they sequenced matched the same DNA from other degraded tissues and gives no evidence of contamination. Additionally, their results successfully matched the DNA of the abundant species of the Flagler County, according to Inverse.

The suspicion of Weakley for 24 years was confirmed. "I long suspected it had been a blacktip shark bite, and it was satisfying to learn the truth," he said.

"How do I feel? I'm continuing to marvel at the achievements of modern science," shared Weakley. "I feel happy to think perhaps I've made some contribution."



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