Sharks Are Ultimate Survivors Of Nature- Know How?
According to a recent study, sharks have emerged as Nature’s ultimate survivors. The asteroid that caused the extinction of the largest creatures i.e. dinosaurs on the planet along with other life forms failed to impact sharks.
A new study reveals that 66 million years ago when organisms like dinosaurs failed an asteroid hit, sharks emerged unharmed. One more thing worth mentioning about the shark species is that they have been around for at least 450 million years now.
The new revelation about the Piscean species came to researchers from the study of teeth of ancient fishes. A team of researchers was looking to understand the genetic diversity of these fish species. In the process, they analyzed 1,239 fossil shark teeth from nine different species spread over a period of 27 million years.
The research has got published in PLOS Biology. It states that sharks (Selachimorpha) are iconic marine predators that have over geologic time, survived multiple mass extinctions. In the paper, researchers stated, “The teeth provide the basis for reconstructing deep time diversity changes affecting different selachimorph clades.”
A famous mass extinction that happened during the end of the Cretaceous period is known to disrupt marine ecosystems as well, but researchers have found that it did not have a similar effect on shark species diversity.
The paper read, “The end-Cretaceous mass extinction event approximately 66 million years ago profoundly disrupted marine ecosystems but has disputed implications for shark species diversity and morphological disparity. Indeed, contrasting interpretations advocate either limited or complex interrelationships of biotic and abiotic drivers that seemingly influenced shark evolution from before, during, and after the mass extinction event.”
The study has found that lineages of sharks were disproportionately impacted. While some shark species were on the decline before the asteroid event, others began to thrive after the event. The paper added, “Extinction and recovery patterns were consistent at global and regional scales.”
Cretaceous Era
Now, after the study, researchers attribute the ability of sharks to surviving the major impact event to their potential of repairing DNA damage.
In a conversation with Daily Mail, the lead author of the study, Mohamad Bazzi said, “The explosive event, that left a 93 mile diameter crater, was not as dramatic for sharks as it was most other vertebrate lineages. Their prolific fossil record is represented mainly by isolated shed teeth, rather than bones as found in other ancient creatures.”
Asteroid Event That Caused Extinction of Dinosaurs
The asteroid that hit the Earth’s atmosphere had a size of a city. After contacting the atmosphere, it further punched into the ground in modern-day New Mexico off the Yucatán Peninsula leading to massive debris smoke there. This debris even blocked the sunlight. The impact left a 200 km wide crater on the surface and as the sunlight faded, Earth’s surface temperature dropped leading to a mass extinction that killed 75 percent of life on the planet.
