Emu People often think that humans started destroying the environment around the time they invented factories, cars and landfills. However, two new studies suggest that our ancestors had major impact on their environment as early as 50,000 years ago, during the Pleistocene Era. New techniques of dating have allowed researchers to tie a massive die-off of large animals in Australia to the arrival of humans during that time. Another study illuminates the relationship between human expansion around the Mediterranean, and a shift in small animal populations due to hunting. These two studies are prompting scientists to rethink the ways in which ancient humans interacted with their environment.
Sexual reproduction is the most common way by which organisms multiply and pass on their genes.
But its popularity has long remained a mystery to biologists. Many years ago, people did not understand the harm toxic chemicals and pesticides could do to people's health and the environment. As a result, many hazardous materials were dumped into streams, buried in landfills, or abandoned when warehouses or manufacturing facilities closed down. Today, people realize the importance of cleaning up sites that have been contaminated with toxic wastes and some scientists are looking to plants to help us clean up the mess. Site posts information about phytoremediation including its benefits, drawbacks, and future uses.