Playing with sperm

Most breast cancer patients do not die from their initial tumour, but from secondary malignant growths metastases , where cancer cells are able to enter the blood and survive to invade new sites. Cooperation confers a competitive advantage by several means, some of these include incapacitation of other competing sperm and aggregation of genetically similar spermatozoa into structures that promote effective navigation of the female reproductive tract and hence improve fertilization ability. These bouts can happen more than once which takes a toll on the physical well- being of the male. Shappi Khorsandi. Another popular drug, venlafaxine, was shown increase the risk users engaging in suicidal thoughts and attempts at suicide. The evolution of insect mating systems. Geoffrey Macnab.