https://www.youtube.com/watch?v=NoFQjAHsWE8 - https://www.youtube.com/watch?v=NoFQjAHsWE8 or https://www.youtube.com/watch?v=NoFQjAHsWE8 ;The Forgotten Prehistoric War That Killed 19 Out Of 20 Men7,000 years ago something happened that was so severe that it permanently left a scar within our DNA...
see also https://en.wikipedia.org/wiki/Population_bottleneck - https://en.wikipedia.org/wiki/Population_bottleneck or https://en.wikipedia.org/wiki/Population_bottleneck ; A population bottleneck or genetic bottleneck is a sharp reduction in the size of a https://en.wikipedia.org/wiki/Population - population due to environmental events such as famines, earthquakes, floods, fires, https://en.wikipedia.org/wiki/Disease - disease , and https://en.wikipedia.org/wiki/Drought - droughts ; or human activities such as genocide, speciocide, widespread violence or intentional culling. Such events can reduce the variation in the https://en.wikipedia.org/wiki/Gene_pool - gene pool of a population; thereafter, a smaller population, with a smaller https://en.wikipedia.org/wiki/Genetic_diversity - genetic diversity , remains to pass on genes to https://en.wikipedia.org/wiki/Future_generations - future generations of https://en.wikipedia.org/wiki/Offspring - offspring . Genetic diversity remains lower, increasing only when gene flow from another population occurs or very slowly increasing with time as random https://en.wikipedia.org/wiki/Mutation - mutations occur. https://en.wikipedia.org/wiki/Population_bottleneck#cite_note-1 - [ https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Self-published_sources -
This results in a reduction in the robustness of the population and in its ability to adapt to and survive https://en.wikipedia.org/wiki/Natural_selection - selecting environmental changes, such as https://en.wikipedia.org/wiki/Climate_change_%28general_concept%29 - climate change or a shift in available resources. https://en.wikipedia.org/wiki/Population_bottleneck#cite_note-2 - Alternatively, if survivors of the bottleneck are the individuals with the greatest genetic https://en.wikipedia.org/wiki/Fitness_%28biology%29 - fitness , the frequency of the fitter genes within the gene pool is increased, while the pool itself is reduced.
And https://en.wikipedia.org/wiki/Paraguayan_War#Casualties_of_the_war - https://en.wikipedia.org/wiki/Paraguayan_War#Casualties_of_the_war or https://en.wikipedia.org/wiki/Paraguayan_War#Casualties_of_the_war ;
Paraguay suffered massive casualties, and the war's disruption and disease also cost civilian lives. Some historians estimate that the nation lost the majority of its population. The specific numbers are hotly disputed and range widely. A survey of 14 estimates of Paraguay's pre-war population varied between 300,000 and 1,337,000. https://en.wikipedia.org/wiki/Paraguayan_War#cite_note-95 - After the war, an 1871 census recorded 221,079 inhabitants, of which 106,254 were women, 28,746 were men, and 86,079 were children (with no indication of sex or upper age limit). https://en.wikipedia.org/wiki/Paraguayan_War#cite_note-96 - The worst reports are that up to 90% of the male population was killed, though this figure is without support. |