Ricki Lewis

I've never been fond of the human Y chromosome. Yes, the all-important SRY gene sets the early embryo on a path towards maleness, but the rest? Mostly DNA borrowed from a long-ago X, peppered with eight long palindromes.

"The Y is a pathetic little chromosome with lots of junk. It is gene-poor, prone to deletion, and useless. You can lack a Y and not be dead, just female," Jennifer Marshall Graves told me years ago when I defiled the Y in The Scientist. She's professor emeritus of Australian National University, an evolutionary geneticist who works on kangaroos, platypus, Tasmanian devils, and various dragon lizards.

But men missing the Y in some of their white blood cells face heightened health risks. That was a mere association a few years ago, but now appears to be causal, according to results of an investigation in Science from researchers at Uppsala University. The research combines clues from mouse studies and epidemiological data from the UK Biobank.

To continue reading go to DNA Science, where this post first appeared.

The Supreme Court justices who dismantled Roe v Wade in Dobbs v Jackson Woman's Health Organization should have taken a refresher course in Bio 101. Their decision is devoid of anything even hinting at modern medical science.

The American College of Obstetrics and Gynecology today released a joint statement from more than 75 health care organizations "in opposition to legislative interference" with women's health care. They conclude:

"Abortion care is safe and essential reproductive health care. Keeping the patient–clinician relationship safe and private is essential not only to quality individualized care but also to the fabric of our communities and the integrity of our health care infrastructure. As leading medical and health care organizations dedicated to patient care and public health, we condemn this and all interference in the patient–clinician relationship."

I couldn't agree more.

To continue reading, go to DNA Science, where this post first appeared.

If a new Planet of the Apes or Jurassic Park film comes out, I'm going to go see it. The latest, Jurassic World:Dominion, didn't disappoint.

A Plague of Locusts

The science is mostly accurate, the bioethics message obvious, and the plot adheres to Isaac Asimov's "change one thing" rule for science fiction. In the world of Jurassic Park, that lone variable is time. We just have to accept that a "titanosaur" like Argentinosaurus somehow grew and developed from a lab-nurtured baby to a 130-foot-tall and 110-ton adult in a few years.

The official summary from IMDb for the new film is vague and continues the impossibly-rapid-growth theme:

Four years after the destruction of Isla Nublar, dinosaurs now live–and hunt–alongside humans all over the world. This fragile balance will reshape the future and determine, once and for all, whether human beings are to remain the apex predators on a planet they now share with history's most fearsome creatures in a new Era.

Four years? Animals radiating around the world? Even rats or rabbits couldn't do that. And the film is actually more about insects.

To continue reading, go to DNA Science, where this post first appeared.

"Our Father" is difficult to watch, especially if you've suddenly discovered as an adult that you have a never-known family of half-siblings, cousins, nieces, and nephews thanks to a long-ago sperm donation. One review dubs the series "Netflix's most gruesome real-life documentary yet." 

It tells the tale of Indianapolis fertility physician Donald Cline, who used his sperm to inseminate at least 96 women (and counting) between 1979-1986. After years of being in the dark, the offspring have found each other thanks to diligent sleuthing by some of the half-siblings and DNA testing. 

"The majority of us live in a 25-mile radius, some within minutes of Cline. I walk around and I could be related to anyone. I've probably met half sibs and we don't even know it," said a son named Guy.

To continue reading, go to Genetic Literacy Project, where this post first appeared.

Whenever I work on a new edition of my human genetics textbook and reach the section on eugenics, which flourished in the United States in the 20th century well into the 1930s, I'm relieved that it's history. But in the summer of 2017, as I wrapped up the 12th edition, the eugenics coverage took on a frightening new reality with the attack in Charlottesville, where white supremacists bellowed "Jews will not replace us!" A president noted at the time, "there are very fine people on both sides."

It's now 2022. I've just finished revamping the section in my textbook on eugenics for the 14th edition. And once again, eugenics is in the headlines, with the attack on Black shoppers at a supermarket in Buffalo, New York. 

As another president once said, "here we go again."

To continue reading, go to Genetic Literacy Project, where this post first appeared.

Tales of time travel have intrigued me since The Time Machine film scared the crap out of me at my cousin Ron's ninth birthday party. Now The Time Traveler's Wife, a novel from 2003 and film from 2009, has resurfaced in series form on HBO.

Emily St. John Mandel's new novel Sea of Tranquility also follows a time traveler, across five centuries. The tale begins in 1912 in Canada and ends, if you look at time as linear rather than looped, in a dark, domed moon colony. The author wrote Station Eleven, so I was thrilled that she has a new book. Although it's fiction, events during the middle time period unfold during a pandemic. It is an eerily familiar backdrop.

The Star Trek Futuristic Precedent

The #1 rule of time travel: you can't go back and change anything. A poignant demonstration of this edict is "The City on the Edge of Forever," considered by some to be the best installment of any Star Trek series ever. It was the penultimate episode of the first season, debuting on NBC on April 6, 1967 and written by Harlan Ellison.

To continue reading, go to DNA Science, where this post first appeared. 

When I was growing up in the 1960s, chewing gum was a big deal.

TV ads showcased the doublemint twins and their stick gum, and the small squares of chiclets. Kids preferred tiny bricks of pink Bazooka with the folded-up shiny papers bearing dumb comics. Girls collected rectangular

Juicy Fruit wrappers, folding them thrice in two dimensions and linking them into loooong chains that we'd save for our future first boyfriends.

We had tea-flavored teaberry gum, and a yummy licorice one with a name that is probably no longer politically correct.

Trident gum offered a sugar-free option, while Dentyne gave the illusion of health. New York City pharmacist Franklin V. Canning invented the gum in 1899, formulated to "sweeten the breath, to keep teeth white," according to the wrapper. Dentyne cleverly combines "dental" and "hygiene."

And an ancient song was entitled, "Does your chewing gum lose its flavor on the bedpost overnight?"

To continue reading, go to DNA Science, where this post first appeared.

I've long been fascinated with the 1918 influenza pandemic because my grandfather Sam survived it. He married his nurse, lived 103 years, and likely had lifelong B cells that held the memory of his encounter with the flu. I wrote "A 1918 Flu Memoir" about him in 2008 for The American Journal of Bioethics.

We know very little about the 1918 pandemic flu, other than what it did to millions. The virus wasn't even identified until 1933. Compare that to the deluge of SARS-CoV-2 genome sequences posted daily, nearly 11 million as I write this.

What we do know about the 1918 flu comes from bits of lung tissue from museum specimens or preserved in permafrost.

To continue reading, go to DNA Science, where this post first appeared.

I originally published When Does a Human Life Begin? 17 Timepoints here at DNA Science in 2013. My intent was to inform those who confuse embryo with fetus with baby by presenting how biologists describe human prenatal development – beginning at fertilization. Human gestation is on average 38 weeks, not 40, according to biology.

I rerun "17 Timepoints" periodically to counter assaults on woman's reproductive rights – which unfortunately happens with disturbing regularity.

In 2017, I reposted when The Federalist published "Life Begins at Conception, Says Department of Health and Human Services."

Then in September 2021, Genetic Literacy Project reran "17 Timepoints" with the updated headline (which I didn't write) Viewpoint: 'The fetus is 1/25th of an inch' — Texas abortion ban bungles the science on when human life begins, contends biologist and professor.'

And along the way, various right-to-lifers have responded to my post with insults to my expertise, but no sign of actually understanding the biology. So it goes …

Now the rerun of "17 Timepoints" is in response to the leaked Supreme Court document threatening Roe v Wade, published in Politico and written by Josh Gerstein and Alexander Ward. To paraphrase Ronald Reagan, here we go again.

To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared. 

The sudden inability to smell and taste that comes with COVID is startling and difficult to describe. I was lucky to experience it only for a few days.

Anosmia is the partial or total loss of the ability to smell, which vanquishes most of the sense of taste, too. The COVID version is more profound than the familiar dulling of the sense from the mucus of a common cold. And it has a different origin.

The odd part of COVID anosmia is that the virus alters gene expression in nerve cells in the nose – even though the virus can't actually enter nerve cells (neurons). Then the temporarily crippled cells can't signal the brain that the person is inhaling near the seashore or passing a garbage dump. Understanding the basis of the secondhand assault may clarify other puzzling effects of the changeling coronavirus – perhaps even long COVID.

Clever experiments recently revealed how COVID anosmia happens. Benjamin R. tenOever and colleagues from the NYU Grossman School of Medicine and Columbia University report their work using golden hamsters and the noses of human corpses in Cell.

First, a closer look at how the sense of smell works.

To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.