Massive genetic study shows how humans are evolving

Bruno Martin
Nature
Originally published 06 September 2017

Here is an excerpt:

Why these late-acting mutations might lower a person’s genetic fitness — their ability to reproduce and spread their genes — remains an open question.

The authors suggest that for men, it could be that those who live longer can have more children, but this is unlikely to be the whole story. So scientists are considering two other explanations for why longevity is important. First, parents surviving into old age in good health can care for their children and grandchildren, increasing the later generations’ chances of surviving and reproducing. This is sometimes known as the ‘grandmother hypothesis’, and may explain why humans tend to live long after menopause.

Second, it’s possible that genetic variants that are explicitly bad in old age are also harmful — but more subtly — earlier in life. “You would need extremely large samples to see these small effects,” says Iain Mathieson, a population geneticist at the University of Pennsylvania in Philadelphia, so that’s why it’s not yet possible to tell whether this is the case.

The researchers also found that certain groups of genetic mutations, which individually would not have a measurable effect but together accounted for health threats, appeared less often in people who were expected to have long lifespans than in those who weren't. These included predispositions to asthma, high body mass index and high cholesterol. Most surprising, however, was the finding that sets of mutations that delay puberty and childbearing are more prevalent in long-lived people.

The article is here.

Note: This article is posted, in part, because evolution is not emphasized in the field of psychology. There are psychologists who believe that humans did not evolve in the way other plants and animals evolved.  I have argued in lectures and workshops that we humans are not in our final form.

The ethics of creating GMO humans

The Editorial Board
The Los Angeles Times
Originally posted August 3, 2017

Here is an excerpt:

But there is also a great deal we still don’t know about how minor issues might become major ones as people pass on edited DNA to their offspring, and as people who have had some genes altered reproduce with people who have had other genes altered. We’ve seen how selectively breeding to produce one trait can unexpectedly produce other, less desirable outcomes. Remember how growers were able to create tomatoes that were more uniformly red, but in the process, they turned off the gene that gave tomatoes flavor?

Another major issue is the ethics of adjusting humans genetically to fit a favored outcome. Today it’s heritable disease, but what might be seen as undesirable traits in the future that people might want to eliminate? Short stature? Introverted personality? Klutziness?

To be sure, it’s not as though everyone is likely to line up for gene-edited offspring rather than just having babies, at least for the foreseeable future. The procedure can be performed only on in vitro embryos and requires precision timing.

The article is here.

First Human Embryos Edited in U.S.

Steve Connor
MIT Technology News
Originally published July 26, 2017

The first known attempt at creating genetically modified human embryos in the United States has been carried out by a team of researchers in Portland, Oregon, Technology Review has learned.

The effort, led by Shoukhrat Mitalipov of Oregon Health and Science University, involved changing the DNA of a large number of one-cell embryos with the gene-editing technique CRISPR, according to people familiar with the scientific results.

Until now, American scientists have watched with a combination of awe, envy, and some alarm as scientists elsewhere were first to explore the controversial practice. To date, three previous reports of editing human embryos were all published by scientists in China.

Now Mitalipov is believed to have broken new ground both in the number of embryos experimented upon and by demonstrating that it is possible to safely and efficiently correct defective genes that cause inherited diseases.

Although none of the embryos were allowed to develop for more than a few days—and there was never any intention of implanting them into a womb—the experiments are a milestone on what may prove to be an inevitable journey toward the birth of the first genetically modified humans.

The article is here.

Federal panel approves first test of CRISPR editing in humans

By Laurie McGinley
The Washington Post
Originally posted on June 21, 2016

A National Institutes of Health advisory panel on Tuesday approved the first human use of the gene-editing technology CRISPR, for a study designed to target three types of cancer and funded by tech billionaire Sean Parker’s new cancer institute.

The experiment, proposed by researchers at the University of Pennsylvania, would use CRISPR-Cas9 technology to modify patients’ own T cells to make them more effective in attacking melanoma, multiple myeloma and sarcoma.

The federal Recombinant DNA Advisory Committee approved the Penn proposal unanimously, with one member abstaining. The experiment still must be approved by the Food and Drug Administration, which regulates clinical trials.

The article is here.