Again the AAAS gets caught spreading stereotypes or biases!
By repeating a narrative it does not become a truth! Or as Oscar Wilde once said: "The truth is rarely pure and never simple" quoted from Oscar Wilde's 1895 play The Importance of Earnest.
It also appears that the researchers were biased. Why would they enter the year 1492 CE as the start dated for the sequenced ancient genomes in their abstract (see below)? The arrival of Christopher Columbus in the Americas? Is this a pretense of exactness or demagoguery?
This research is based only on two individuals found in one cemetery in Chile! This study also involves some serious estimation work on the evolution of the virus. Was this properly validated?
Maybe the Europeans of 16th and 17th century did not think that smallpox was so contagious anymore. Very likely, these Europeans did not understand that the indigenous population might be more vulnerable to this virus.
What diseases were spread from indigenous people to the early arriving Europeans?
"The primary and practically sole major disease widely accepted by historians and scientists to have passed from the Americas (including South America) back to early European arrivals is syphilis (specifically non-venereal or venereal treponemal variants that adapted into the European syphilis epidemic of the 1490s)." (Google Search)
Syphilis in the 16th century was significantly severe, disfiguring, and frequently deadly. (Google Search)
Or why did not other, more contagious diseases evolve in South America or the American continent before the arrival of Europeans?
"Sometime around the turn of the 17th century, two people died in northern Chile. Their disease-ravaged bodies were bundled in layers of textiles, buried in an Indigenous cemetery, and naturally mummified by the desert environment. Now, scientists have identified their killer: smallpox. The virus’ genome found in their bones and described today in Science represents the first molecular evidence of the disease in the colonial Americas, confirming historical accounts of the disease arriving with European contact and eventually killing millions of Indigenous inhabitants. ...
surprising hints that the smallpox virus’ evolution might have slowed down between the 16th and 18th centuries ...
the Chilean strain differed from modern smallpox, but thinks it was likely less virulent. ...
Archaeologists had previously described some of the mummies as having skin lesions, which they attributed to arsenic exposure. But smallpox could also leave such lesions. ...
Evolutionarily, the Chilean strain sits between pox viruses circulating during the Viking age and a virus isolated by Poinar’s team from a Lithuanian child mummy who died between 1643 and 1665 C.E. It likely diverged from other smallpox lineages around 1296 C.E., and went extinct before the early 20th century.
By estimating how long it would take for the strain’s hallmark genetic variants to evolve and combining that with radiocarbon dates from one of the mummy’s hairs, the scientists deduced that the outbreak in northern Chile occurred between 1492 and 1631 C.E."
"... Smallpox was one of the deadliest diseases introduced to the Americas during European colonization. The rapid spread of the disease across North, Central, and South America is estimated to have resulted in the deaths of three to four million people, particularly among Indigenous populations with no prior immunity. ...
Bruno González and colleagues identified ancient smallpox virus DNA in two mummified Indigenous Inca-Early Colonial-era individuals recovered from northern Chile, who lived between 1492-1631 CE."
Caveat: I did not read the research article.
From the editor's summary and abstract:
"Editor’s summary
Smallpox was introduced to the Caribbean by European colonialists before quickly spreading south. Romero González et al. sequenced ancient smallpox genomes from two likely Incan individuals from Chile dated between about 1492 and 1631 CE. Skin lesions on these mummified remains were previously attributed to arsenic exposure, but they are also consistent with smallpox infection.
Phylogenetic analyses suggested that this smallpox strain was most closely related to ancient European lineages that went extinct before the 20th century. These represent the earliest smallpox genomes found in the Americas and help set a timeline for gene loss during the evolution of this deadly virus. ...
Abstract
Smallpox was a major driver of population collapse in the Americas after European contact, yet the genetic identity of the causal strains remains unknown.
Here, we report the first ancient smallpox genomes in the Americas, dating to approximately 1492–1631 common era (CE), recovered from two Inca-Colonial individuals in northern Chile.
These genomes form a now-extinct lineage that diverged around 1296 CE, after the splitting of early medieval European strains but before the emergence of modern variola lineages, providing direct molecular evidence for smallpox introduction through European colonization.
We further identify a constant tempo of gene inactivation until the late 16th century, followed by a phase of constraint and a subsequent rebound in substitution rates, linking variola virus evolution to major shifts in human demography and epidemiology."
