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.
It has been only 100 years since humans first occupied the continent of Antarctica (1899), and a mere 180 years since seafarers first saw the islands of the Antarctic Peninsula (1819). Yet even before they laid eyes on it, most early explorers were convinced a large, southern continent existed.