Western officials say important differences still remain, especially regarding enriched uranium.
Scientists have used Ebola disease spread patterns and airline traffic data to predict chances.
The country last month raised its international threat level to the second-highest classification.
According to historical record, the monarch was killed in battle on Bosworth Field on 22 August, 1485.
A broad rise for the greenback was the main bet of most major investment houses this year.
This comes after more than 500 Britons have left the UK to fight Jihad in Syria and Iraq.