I have been putting some thought on why people have different blood types lately. Actually, the answer to this question is quiet simple at first: "nature favors diversity".
Yet, research shows blood type refers more than blood. It is suggested that blood types reflect some characteristics of the individual as well. For instance, A-type people are more susceptible to get cancer than B or 0-type people have the best teeth.
What happened during the way that living organisms diverged into different blood types? Is it likely that the diversification will continue? Will our offspring have more blood types; like a brand new C type? Or how about a D Rh-?
Thanks to cyber world, Google is the answer for most of my questions.. Here is what you get once you type "why people have different blood types" into search bar:
http://www.sciam.com/article.cfm?id=why-do-people-have-differ
Even though this article of Dr. Klein does not really elaborate "the reasons" for having different blood types, it does give good reflections on the beauty of the diversification on our veins.
Knowing that the differences on blood types can protect us from having diseases, one can anticipate that in the presence of a single type of blood, destroying whole human being would be a piece of cake for a pathogen. Clearly, I am happy the way it is now. Salute to diversity!
Subscribe to:
Post Comments (Atom)
Posts
2 comments:
The answer "nature favors diversity" really does nothing to explain why people have different blood types.
Its like answering the question "how does a light switch work?" by saying that "If it didn't no one would have them in their house!"
There must have been an event where people with that mutation were given greater fitness and were able to outbreed as a result.
I have been told that those blood proteins give an antibacterial resistance. It would make sense therefore that in a region where this is important that would win out. In other regions where bacteria isn't as big an issue you could be O.
I know someone who has studied this. I will direct her to your blog. Maybe she has some examples of how blood proteins have been selected for.
If the blood proteins give an antibacterial resistance (which they do) and if the person who has that proper blood type survive, we found an explanation for "why a blood type is needed".
But if you think that there are different types of blood proteins, and only the ones that were beneficial survived, you wonder why there was a diversity at all? (and better yet, how?)
Therefore my point at "nature favors diversity" is not to describe why people have blood types. It was more to interpret the reasons for the differences in the blood types. As you point out, the antibody resistance is clearly one if which.
I do agree though, this is not an adequate answer. :) That's why I can't wait for the examples of how blood proteins might have been selected for -- thanks for your interest.
Post a Comment