List of the 100 most densely populated cities in the United Kingdom, measured in people per square miles. 1  Portsmouth, Hampshire â 15,336. 2  London â 13,870. 3  Leicester, Leicestershire â 11,800. 4  Glasgow, Glasgow â 8,542. 5  Bristol, Bristol â 13,398. 6  Liverpool, Merseyside â 12,790. 7  Stoke-on-Trent, Staffordshire â 11,939.
In 1961 at the Wistar Institute in the US, Hayflick researched a phenomenon later called the Hayflick Limit, or the claim that normal human cells can only divide forty to sixty times before they cannot divide any further.
Mutations do even more damage than the Hayflick limit and associated cancer rates suggest. Ever since August Weismann published The Germ-Plasm: A Theory of Heredity in 1893, a discrete separation has been shown to exist between body cells (the soma) and germ-line cells (germplasm).