Most Harmful Mutations Surviving In People Arose In The Last 10,000 Years
2012-11-29 0:00

From: Science 2.0

Evolutionarily speaking, most of the harmful mutations that still exist in people are recent, which makes the case that nature is still out to get us, even in modern times.

A study dated the age of more than 1 million single-letter variations in the human DNA code and revealed that 86 percent of the harmful protein-coding mutations of this type arose in humans just during the past 5,000 to 10,000 years. These kinds of mutations change one nucleotide an A, C, T or G in the DNA sequence.

Some of the remaining mutations of this nature may have no effect on people and a few might be beneficial, according to the researchers. Each specific mutation is rare and they suggest that the human population acquired a lot of these single-nucleotide genetic variants in a relatively short time.

To place this discovery in the context of the prehistory and ancient history of people, humans have been around for roughly 100,000 years. In the Middle East, cities formed nearly 8,500 years ago, and writing was used in Mesopotamia at least 5,500 years ago.

The researchers assessed the distribution of mutation ages by re-sequencing 15,336 protein-coding genes in 6,515 people. Of them, 4,298 were of European ancestry, and 2,217 were African.

"The spectrum of human diversity that exists today is vastly different than what it was only 200 to 400 generations ago," said Dr. Joshua Akey, associate professor of genome sciences at the University of Washington in Seattle. He is one of several leaders of a multi-institutional effort among evolutionary geneticists to date the first appearance of a multitude of single nucleotide variants in the human population.

The researchers based their explanation for the enormous excess of rare genetic variants in the present-day population on the Out-of-Africa model of the human diaspora to other parts of the world.

"On average, each person has about 150 new mutations not found in either of their parents," Akey said. "The number of such genetic changes introduced into a population depends on its size."

Larger populations, continuing to multiply by producing children, have more opportunities for new mutations to appear. The number of mutations thereby increases with accelerated population growth, such as the population explosion that began 5,115 years ago.

During the Out of Africa migration of some early humans into Europe and beyond some 50,000 years past, a population bottleneck occurred: The number of humans plummeted, and the shrinking remnant became more genetically similar. Back then, mutations that were only slightly damaging had a greater probability of being carried from one generation to the next, Akey explained.

"Those mutations dont influence the ability to survive and reproduce," he said. "The Out of Africa bottleneck led to inefficient purging of the less-harmful mutations."

They found that, compared to Africans, people of European descent had an excess of harmful mutations in essential genes, which are those required to grow to adulthood and have offspring, and in genes linked to Mendelian, or single-mutation diseases. The study team also observed that the older the genetic variant, the less likely it was to be deleterious. In addition, certain genes, they learned, harbored only younger, more damaging, mutations that surfaced less than 5,000 years ago. These include 12 genes linked to such diseases as premature ovarian failure, Alzheimers, hardening of the heart arteries, and an inherited form of paralysis.


Read the full article at:

Related Articles
Genetic mutation turns tot into superboy
Introduction to Human Genetics: Mutation
Top 11 Most Common Human Mutations
Most Mutations Come from Dad: New Insights Into Age, Height and Sex Reshape Views of Human Evolution

Latest News from our Front Page

Catastrophic Fertility Rates
2015-10-14 1:00
YouTube description: Back in February, Reactionary Expat and I recorded a three-and-a-half hour conversation. ... This first instalment sees us discussing worldwide fertility rates. It's bad news everywhere. Source:
Official Working for the Swedish Government: "There Is No Native Swedish Culture."
2015-10-13 23:54
This brave woman, who is just such a counter culture rebel is trying to convince Swedes - yet again - that there isn't such a thing such as a "native Swedish culture." This courageous woman, Ingrid Lomfors, who just happens to be Jewish, has not only been educated in Jerusalem at the Hebrew University. She's also been trained at the Hebrew ...
Whistleblower doctor explains horrific reality dealing with Muslim invaders in Germany
2015-10-14 0:53
This is unbelievable. A Czech doctor, who works in a German hospital, is so disgusted and overwhelmed with the Muslim migrant invaders that she is threatening to leave the country and go back home to the Czech Republic. She explains, via an email letter (because the press is forbidden from reporting on this), how horrific the conditions are in these hospitals, ...
The Final Leaked "Secret" TPP Text is All That We Feared. Top Down Control of the Internet
2015-10-14 0:40
Since we now have the agreed text, we’ll be including some paragraph references that you can cross-reference for yourself—but be aware that some of them contain placeholders like “x” that may change in the cleaned-up text. Also, our analysis here is limited to the copyright and Internet-related provisions of the chapter, but analyses of the impacts of other parts of ...
Jewish leaders say “no” to Syrian refugees on anti-semitism concern - NL Times
2015-10-14 0:14
The Jewish community of Amsterdam-Zuid are concerned about the arrival of a refugee center in Amstelveen-Noord, which local residents were informed about on Monday night. The proposed shelter will house 400 refugees, mostly from Syria and Iraq.  This weekend it was announced that the municipality of Amstelveen intends to shelter refugees in the office building on Laan van Kronenberg – less ...
More News »