51.   Thanks to conveniences like elevators and garage-door openers, modern humans have practically forgotten about their legs.

52.   That was about when anatomically modern humans first appeared in Africa and later drove archaic relatives to extinction.

53.   The cause of the Neanderthal disappearance remains as unclear as the exact evolutionary relationship between them and modern humans.

54.   The DNA analyses may help to choose between three rival theories of how modern humans evolved.

55.   The new data also support the widely held but still contentious view that modern humans had little or no genetic admixture with the Neanderthals.

56.   The new findings, moreover, indicate that the Neanderthals, relatives of modern humans, could have had the same gift for speech.

57.   The size of the brain of Neanderthals was well within the range of that of modern humans.

58.   The researchers believe that modern humans are the product of worldwide gene flow between ancient hominids.

59.   The short strip of the genetic material DNA indicates that Neanderthals did not interbreed with modern humans.

60.   Then the Neanderthals lost out in the competition with modern humans and disappeared.