You may have heard rumours that deodorants and antiperspirants could cause breast cancer. But these concerns were started by an e-mail hoax. There is no convincing evidence that antiperspirants and deodorants cause breast cancer. Why are the claims about deodorants and breast cancer wrong? The original e-mail claimed that antiperspirants stop your body from sweating out poisons. It suggested that these toxins build up in the lymph glands under the arm and cause breast cancer.
Sharks Have Been Around For Longer Than Trees. The earliest sharks swam through Earth's oceans around 420 to 450 million years ago, a time when there were no true trees on land. Paleontologists can trace the history of sharks this far back by examining fossilized shark teeth and scales.
Some living groups have ancient histories. For example, sharks have existed as a group for over 350 million years! Today, sharks and rays (elasmobranchs) are represented by over 600 species that show a remarkable range of ecological and morphological diversity. Unlike the true fishes, sharks do not have internal bone, but instead have a cartilaginous skeleton.