An alarming message about deodorant use and breast cancer began circulating on the Internet in the 1990s, spread via e-mail and message-board postings. It continues to resurface now and again and causes a great deal of concern about the safety of items many of us use every day. So let's take a look at the evidence.
How long have sharks been in existence? A: Geological records show that modern shark species have existed for between 201 million and 174 million years. Earlier fish species similar to sharks existed as early as between 419 million and 359 million years ago.
Shark lifespan vary by kind. Although the majority of types live 20 to 30 years in the wild, there are some kinds that live much longer than others. For example, the spiny dogfish has one of the longest lifespan at more than 100 years, while the blue shark in the wild has an average lifespan of 15-16 years.andbar sharks or Brown sharks are considered to live between 20 and 30 years. Research made by Joung (2004) identified to be about 20 years of age.