20 January, 2013
Scientists have made an unexpected and unsettling discovery - a
large number of new and previously unseen mutations have been
detected among humans.
There are those who suggest that there will soon be fantastic X-men
among humans. These super earthlings do not come out of secret
laboratories, as in famous blockbuster movies, but are born
naturally. Other scientists are less optimistic and consider the
unforeseen development can to lead to unknown changes in the human
This unexpected and terrifying discovery is a result of a study
conducted by scientists from Cornell University (USA) and University
When they examined genes of several thousands of people from around
the world, it turned out that mankind has acquired over the past few
years new, previously unseen mutations.
Is a new human race being born?
The scientist studied 202 genes in 14,002 people.
The human genome contains some 3 billion
base pairs; the scientists studied 864,000 of these pairs. While
this is only a small part of the genome, the sample size of 14,002
people is one of the largest ever in a sequencing study in humans.
This project led by John Novembre of the University of
California Los Angeles and Vincent Mooser of UK-based drug
company GlaxoSmithKline, reports that more than 95% of variants
found by sequencing 202 genes in 14,002 people were rare, and that
74% of the variants were carried by only one or two people in the
"I knew there would be rare
variation but had no idea there would be so much of it!" said
the senior author of the research, John Novembre, an assistant
professor of ecology and evolutionary biology and of
bioinformatics at UCLA.
In the study, 10,621 people had one of
12 diseases, including coronary artery disease, multiple sclerosis,
bipolar disorder, schizophrenia, osteoarthritis and Alzheimer's
disease; 3,381 did not have any of the diseases.
"The large sample size allows us to
see patterns with more clarity than ever before," Novembre said.
"If rare variants are like distant stars, this kind of large
sample size is like having the Hubble Telescope; it's allowing
us to see more than before.
We see a ton of rare variation, and these rare variants more
often make changes to proteins than not. In that way, this study
has important implications for the genetic basis of disease in
humans. It's consistent with the idea that many diseases may be
partly caused by rare variants."
"Research carried out fifty years ago, showed that the mutant
gene had only one man among a thousand, and now five people",
explained John Novembre.
What is causing the
Previously it was thought that genetic abnormalities are caused by
radiation, viruses, transposons and mutagenic chemicals, but now
scientists have identified yet another factor that results in
Human population growth helps to explain the large number of genetic
variants, the scientists said.
Mutations can cause unknown changes in the human body.
"The fact that we see so many rare
variants is in part due to the fact that human populations have
been growing very rapidly," Novembre said. "Because the human
population has grown so much, the opportunity for mutations to
occur has also grown.
"Some of the variants we are seeing
are very young, dating to population growth since the invention
of agriculture and even the Industrial Revolution; this growth
has created many opportunities for mutation in the genome
because there are so many transmissions of chromosomes from
parent to child in large populations."
As a result of overpopulation, rare gene
variants are much more likely to occur.
And scientists do not rule
out that soon there may be new types of mutations that lead to
unknown changes in the human body.
Is a new race of
X-men being born?
There are scientists who see benefits with mutations. Professor Darren Kessner of
University of California has for example suggested that among
Earthlings there will soon be a fantastic group of "X-Men."
They beings do not come out of secret
laboratories, as in the famous blockbuster movies, but are born
Will it be "us" and "them"?
"New mutations are the source of
inherited variation, some of which can lead to disease and
dysfunction, and some of which determine the nature and pace of
evolutionary change. These are exciting times.
We are finally obtaining good reliable estimates of genetic
features that are urgently needed to understand who we are
genetically," said Joseph Nadeau, from the Case Western Reserve
University in the US.
Both useful and harmful mutations have
always existed as a completely normal phenomenon, but if the number
of mutations increases dramatically, one cannot help wondering what
implications this development will have for the human race...