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humanity might be evolving boring than scientist had thought , according to a new analysis of the genomes of two mob , but there is a vast divergence between people .
The researchers , reporting their findings June 12 in the journal Nature Genetics , base their measurement of evolution speed on the number of new mutations that take place during one propagation in each of the families . A slower mutation charge per unit means we probably separated from chimpanzees evolutionarily longer ago than antecedently thought , the researcher say , sum that the finding may have medical implications , if some groups of people are more mutant - prostrate than others .
Humans are acquiring genetic mutations at a slower rate than expected, suggesting we split from our common ancestor with chimpanzees longer ago than once thought.
" This makes us guess about what are the underlyingmechanisms of these mutation , other than just a random physical process , " said study investigator Philip Awadalla , of the University of Montreal in Canada . " Why are there differences in the rate or accumulation of mutation in mortal ? "
The mutations rate seems to be highly variable , Awadalla aver , and could be impress by age and environmental exposure to toxin , among other factors . [ Top 10 Mysteries of the First Humans ]
Tiny tweaks
Every person has two copy of each of their genes , one from the female parent ’s egg and the other from the father ’s sperm . These two copies are quite similar , but have some random dispute .
Then , when the somebody creates sperm ( or testicle , if a char ) , new changes occur by accident in the leave copy of the genome that gets passed down to the offspring . By sequencing both the parents ' and the fry ’s genome for two home , they could see which chromosomal mutation were already present and which were new to the offspring .
The investigator found that on intermediate , humankind seem to have about 60 new variation give down every generation — that ’s 60 change out of 6 billion letter , or bases , that make up the genome . Previous methods , which indirectly bet the rate , overestimated that identification number to be about 100 to 200 , the investigator said .
This think of that we are accumulating new genetic mutations — the foundation of development — about a third as quickly as previously thought . If this sport rate has been unwavering throughout human development , it pushes the fork between humans and chimps back 7 million twelvemonth in the first place . Some early grounds indicate thatchimps may be evolve quickerthan humans , though Awadalla said they would wish to see how they heap up using this whole - genome sequencing method .
Mutating mother
Luckily in the case of the families the researcher studied , the mutations were n’t life-threatening . Most of them were outside of the factor , in areas of the genome called " non - coding , " which do n’t convey protein - making code to carry out any mathematical function .
scientist had hypothesized that because world make so many more copy of their genome when they make sperm ( C of one thousand thousand every twenty-four hours ) , they might be moreprone to lapse on new mutations . The researchers found that this was n’t completely dependable . While one of the two family studied had 92 percent of their mutations passed down from the father , the other had only 36 percent .
" We always believe most of the mutations were total from men , " Awadalla told LiveScience . " In one family , there were more mutation in the male , but the next family the male had fewer mutations than the female person did — it was very surprising . "
The root of these mutations seem to be diverse . They could be induce by years or other natural factors , since genome copying can get sloppy over sentence . It could also be due to genetic differences that hold in the DNA - copy machinery , which could affect the rate at which these genetic mutation come in unlike people . It ’s also possible that vulnerability to toxin in the environment could impact the mutation pace , Awadalla said .
