Angela
Elite member
- Messages
- 21,823
- Reaction score
- 12,329
- Points
- 113
- Ethnic group
- Italian
A group of scientists at the University of Manchester claims to be able to show the evolution of the sense of smell through tracing the sensitivity to emitted by pork (and which is found in wild boar).
This is the study:
Global Survey of Variation in a Human Olfactory Receptor Gene Reveals Signatures of Non-Neutral Evolution
This is a link to the article:
http://www.manchester.ac.uk/discover/news/article/?id=14799
"Most receptors can detect more than one smell, but one, called OR7D4, enables us to detect a very specific smell called androstenone, which is produced by pigs and is found in boar meat. People with different DNA sequences in the gene producing the OR7D4 receptor respond differently to this smell - some people find it foul, some sweet, and others cannot smell it at all. People's responses to androstenone can be predicted by their OR7D4 DNA sequence, and vice versa."
"For example, they found that populations from Africa - where humans come from - tend to be able to smell it, while those from the northern hemisphere tend not to. This shows that when humans first evolved in Africa, they would have been able to detect this odour.
Statistical analysis of the frequencies of the different forms of the OR7D4 gene from around the world suggested that the different forms of this gene might have been subject to natural selection.
One possible explanation of this selection is that the inability to smell androstenone was involved in the domestication of pigs by our ancestors - andostroneone makes pork from uncastrated boars taste unpleasant to people who can smell it. Pigs were initially domesticated in Asia, where genes leading to a reduced sensitivity to androstenone have a high frequency."
Well, all I can say is that if this is true, the 20% or so European ancestry in African Americans is enough to confer the gene mutation to the entire population, because their diet is extremely high in bacon, ham, and other pork products.
This is the study:
Global Survey of Variation in a Human Olfactory Receptor Gene Reveals Signatures of Non-Neutral Evolution
This is a link to the article:
http://www.manchester.ac.uk/discover/news/article/?id=14799
"Most receptors can detect more than one smell, but one, called OR7D4, enables us to detect a very specific smell called androstenone, which is produced by pigs and is found in boar meat. People with different DNA sequences in the gene producing the OR7D4 receptor respond differently to this smell - some people find it foul, some sweet, and others cannot smell it at all. People's responses to androstenone can be predicted by their OR7D4 DNA sequence, and vice versa."
"For example, they found that populations from Africa - where humans come from - tend to be able to smell it, while those from the northern hemisphere tend not to. This shows that when humans first evolved in Africa, they would have been able to detect this odour.
Statistical analysis of the frequencies of the different forms of the OR7D4 gene from around the world suggested that the different forms of this gene might have been subject to natural selection.
One possible explanation of this selection is that the inability to smell androstenone was involved in the domestication of pigs by our ancestors - andostroneone makes pork from uncastrated boars taste unpleasant to people who can smell it. Pigs were initially domesticated in Asia, where genes leading to a reduced sensitivity to androstenone have a high frequency."
Well, all I can say is that if this is true, the 20% or so European ancestry in African Americans is enough to confer the gene mutation to the entire population, because their diet is extremely high in bacon, ham, and other pork products.