the definition of ethnic that is scientific is the one that a group of people identifies with each other because of the common ancestry they share. There are other definitions, just like there are multiple definitions for lots of words.
When this definition is used, ancestry (that you're referring to here) is not explicitly a biological term in any sense whatsoever. It refers to the generations of culture being built on the foundation of a geographic group of people who have segregated themselves from other groups, and built their own identity. Their identity stems from many justifications-- one of them can be skin colour, which is rooted in the genetic code for a human-- however, as w've mentioned, two people having the same skin pigment does not make them the same race. Please understand this. This is definite proof on how race is social.
If you can not see that groups of people descend from different ancestors and evolve differently into different populations, then you are blind. Either that or you are being dishonest with yourself.
Groups of people are not evolving. Please re-consider what your definition of evolution is. If people were evolving into different populations, then the different populations would not be able to mate with each other.
Certain genes are naturally selected based on the appropriateness on given generations of people living with a particular geographic setting. Hence, people living in sub-Saharan Africa tend to have a higher concentration of melanocytes within their skin. If this is your pure justification of the evolving of humans into separate population groups, then every single scientist and/or social scientist would cry laughing.
If you want to keep arguing about semantics, then feel free. I am sick of it. Populations are differnt, and words like race, ethnicity, black, white, yellow, living, human, green, etc. are the words that humans have come up with to describe those differences.
Yes, populations are different. The words generated to describe these differences are not based on biological differences-- they're based on social constructions of what defines two 'races' as different. Why are people from Fiji not considered black? You continue to ignore this question.
The definition of a social construct is an invented thing that has no basis in the natural world. If you can really tell me that human biological differences have no basis in the natural world, then you are a lazy biology student.
They claim to have a basis in the natural world-- however, you have yet to point to me what these natural, biological justifications are. We've gone over how skin-colour is an ineffective means to determine race. What else do you have to your disposal?
I think you are trying to be a social scientist on this front however, and it is beyond ridiculous that you are arguing that humans are not biologically diverse. At the very least you should understand biological diversity.
I do understand biological diversity. I am quite experienced, and knowledged particularly when it comes to the human genome.
Here's a question of you: do you think, after computing statistical/regressional analyses, that there is a significant difference in the genome between people within 'the same race', and dudes from from Finland vs. dudes from Senegal?
Understand that a genome has >20000 genes (there are more that we don't yet know about). Understand that for every gene that determines a superficial visible human characteristic, there are 1000 that determine things within the body. Understand that two Africans could have COMPLETELY different genetic profiles within their physiology, yet be considered more similar in society than a Swede and a Spaniard with identical internal genetic profiles, but different on account of 6-20 genes in terms of eye colour, skin colour, and hair colour.
This is where your lack of genetics knowledge is showing. This is why race is not biological: it uses less than 1% of genes to separate populations in the name of 'science', while disregarding the majority of the human genome. This is why every single social and biological scientist agrees that race is social, and not biological.