More humans are growing an extra blood vessel in our arm that 'feeds' our hands, study shows

Aug 31, 2020
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"To compare the prevalence of this persistent blood channel, Lucas and colleagues Maciej Henneberg and Jaliya Kumaratilake from the University of Adelaide examined 80 limbs from cadavers, all donated by Australians of European descent. "

What other studies do you have? This is a very specific sample of a specific population and does not cover other ethnicities or other regions of the world...Please add some more statistically relevant data
 
Oct 12, 2020
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I have an issue with this as an evolutionary trend - natural selection as the driving force behind evolution requires that subtle variations in a species create an advantage, that over generations cause that variation to be more successful in reproducing. That is the mechanism. How is this process occuring in the case of this artery? Given that the study is not flawed, there is undoubtedly another non-genetic process involved here - perhaps the authors might consider (for example) dietary changes over the 20th century?
 
Jan 16, 2020
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There are some unanswered questions here. For instance, what is the advantage of the extra blood flow to the hands? Evolutionary changes only occur when having something allows you to pass on your genes better than not having it, or vice versa. Unless people with the extra artery are far more successful, or live to adulthood where those without the artery do not, evolution may not be playing a part in this. Since a small sample of mankind was studied, it is likely that some segments of humankind has always had this extra artery, but no one has ever bothered to check for it.
 
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Aug 30, 2020
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Growing an extra artery is not neccessarily an advanvatage, but merely a change as to our lifestyle. I.e. Many people started typing in the late victorian period and even more so today. This could be the reason why these changes are happening. Also on top of this, I have surmised that every one can actually change their own dna in their life time. What you do in the first 25 years of your life are the most important that you could do to maintain a healthy life and to produce the next generation!
 
Oct 13, 2020
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The fact that a semi-dormant artery runs through our forearms clearly indicates that there was once a need for this additional blood flow. Perhaps this artery was initially formed in a time when enhanced dexterity was essential for survival. For modern times the dexterity needed for keyboarding and thumbing cell phone text (or even penmanship - still) has excited the artery's control mechanisms. This could explain the new prominence, but how many 200,000+ year-old cadavers does science have to work with? And the concept of a dire need for enhanced dexterity is also worth some thought.

There is also the possibility that the artery was more functional in the not so distant past, when manual labour - particularly in largely agrarian societies - was more widespread. Manual labour has become less prominent in Western societies with the advent of the Industrial Revolution, and the subsequent development of steam and electrical energy, closely followed by the introduction of internal combustion engines enabled by the vast amount of energy released in hydrocarbon exploitation. This more recent de-emphasis on manual labour isn't uniformly global, so, as other posters have pointed out, a wider sample size might find that other societies have contnued to have a functional mid-forearm artery.
 
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