Scientists have been uncorking long, thin cylinders of soil from wetlands and riverbeds in an attempt to look back in time and understand the impact humans have had on nature. The results have made them radically rethink previous assumptions about when this started. Dr Mottl and his colleagues have been extracting "mud cores" from the depths of lakes and wetlands. These long, tightly compacted cylinders of earth contain a record of exactly what grew in that soil when, going back millennia. Analysing these cores of mud, looking at the pollen that has settled in each layer, has brought an entirely new understanding of when human activity started changing vegetation. Scientists had expected to see the first "signal" of human intervention a few centuries ago, when landscapes really started to transform during the Industrial Revolution. Pollen records from the mud core research have led them to radically readjust that assumption, and track our species' first impact on the natural world back to about 4, years ago.

Php curl ssl. Taehyung, Jimin future spouse tarot reading Part 2Future Spouse Edition Love tarot reading where you'll find out who's the future wife of Jungkook Saturn represents commitment, responsibility, discipline, and Venus represents loveeee.

Pictured here is a moon jellyfish, Aurelia aurita. No one likes the thought of growing old. Despite our many human endeavours to escape or delay the process of ageing, it seems to be an inevitable part of life. There is a word for it: senescence. At the cellular level, it means cells stop dividing and they eventually die.