Proud Mary

Mary Mallon was proud of her craft. 

At the turn of the 20th century, Mary was in demand by wealthy Manhattan families for her skills as a cook. One day, a city official, George Soper, knocked on the door of the fancy brownstone where Mary was employed. 

He had a few simple requests to make of Mary. Could he please have a sample of her blood, her urine, and her feces? Oh, and, this little question: Did she regularly wash her hands after going to the bathroom?

That was one question too many for Mary. She grabbed a carving fork, swore, and lunged for the man, who wisely exited the home.

And you thought the Target and Walmart anti-maskers overreacted.

Four months prior to his abrupt ouster from Mary’s place of employment, Sober, a New York City sanitary engineer, was asked to investigate an epidemic that would eventually sicken thousands of New Yorkers. Soper began by interviewing a particularly hard-hit family in their Long Island summer home. 

Just weeks into their vacation, the family’s nine-year-old daughter fell seriously ill. All told, six out of eleven members of the household, both family and staff, fell sick. 

Soper interviewed the family and discovered that the cook – Mary Mallon – had returned to New York City soon after, apparently healthy as a horse. 

New York was in the midst of a typhoid fever epidemic. Typhoid fever is caused by Salmonella bacteria and in 1907, was fatal in ten percent of infections. Immunization against typhoid fever was four years away and an effective antibiotic was almost forty years away. Carried in feces and usually found in areas with poor sanitation, typhoid fever’s appearance in wealthy areas was a mystery.

But Soper was onto to something. He questioned the family about the menus prepared by Mary, and discovered that shortly before illness broke out, Mary had served her Sunday specialty: homemade ice cream and fresh peaches. Compared to her hot cooked meals, Soper concluded that “no better way could be found for a cook to cleanse her hands of microbes and infect a family.”

Soper searched New York for four months, looking for Mary Mallon. In his search, he identified eight families for whom Mary had cooked, going back several years. Seven families had outbreaks, with twenty-two sick and several deaths. 

In a few years, newspapers would dub Mary Mallon “Typhoid Mary”.

It took police officers, an ambulance, a female doctor, and a foot-chase over the backyard fence to finally bring Mary in for testing. Mary tried her best to resist, holding her stool sample as long as possible. Ultimately, nature called, and Mary tested positive for high levels of Salmonella. Completely and absolutely healthy, Mary denied ever being sick with Typhoid.

She was quarantined on a hospital island for two years, producing typhoid-positive samples the entire time. 

She sued the health department, lost, but was finally freed from the hospital in 1910. Mary agreed to check in regularly with the health department, and importantly, Mary agreed never to work as a cook again. 

After a while, Mary stopped checking in and, feeling fit as a fiddle, returned to cooking: for a hotel, a Broadway restaurant, a spa, and a boarding house.

In 1915, typhoid fever broke out in a New York maternity hospital. At least twenty-five nurses, doctors, and staff were infected, and two died. The cook was a woman named “Mary Brown” who, surprise, surprise, turned out to be Mary Mallon. 

Mary was again transferred to the quarantine island, where she lived until her death in 1932, adamant that she had never been sick with typhoid. 

Mary was the first known case of a healthy carrier in the United States. She was traced to the infection of at least 122 people, including five deaths. In 1907 alone, 3,000 New Yorkers were infected with typhoid, most likely due to Mary. 

Mary’s legacy as an asymptomatic carrier of a deadly disease has informed every widespread disease outbreak since. 

Forty percent of Covid-19 infections have no symptoms. A Boston homeless shelter had 147 infected residents, but 88 percent of them had no symptoms. A Tyson poultry plant in Arkansas had 481 infections, and ninety-five percent were asymptomatic. Prisons across multiple states found 96 percent of infected people were asymptomatic. 

A large number of infected but asymptomatic people is a good thing, of course, but that’s not the whole story. Apparently, seemingly healthy people are just as capable of carrying large viral loads and infecting others as are people with symptoms. 

Compounding the situation are the “super-spreaders”. Super-spreader events, where a single person infects a large number of people, are widely documented. 

The World Health Organization initially did not recommend population-level face masking, but changed their recommendation in June 2020 when the extent of transmission by asymptomatic individuals was confirmed. 

It wasn’t a flip-flop. With new data, science changes its mind. 

A poor immigrant with little education, Mary can possibly be excused for not understanding the nuances of being an asymptomatic carrier. 

But we should know better. When you wear a mask in public spaces, you are probably protecting yourself a bit. But mostly, you’re protecting everyone else in case you are one of the asymptomatic carriers. 

Love your neighbor as yourself.

A popular illustration of the day, depicting Mary cracking skulls like eggs into a frying pan.

******

And as You speak
A hundred billion creatures catch Your breath
Evolving in pursuit of what You said
If it all reveals Your nature so will I

(Hillsong United “So Will I“)

******

Meet Denny: A Front-Row Seat in the Story of Human Evolution

I love a good “best of” list at the end of each out-going year. A study by scientists who ate Legos and studied their “passing” made one such list for 2018 (Everything is Awesome: Don’t Forget the Lego). To the Google for more info on that one. My favorite top science story for the year was the story of Denny, a child from a very surprising blended family.

A very tangled family tree

Have you seen this poster?

The_March_of_Progress

The March of Progress, or The Road to Homo Sapiens was originally published by Time-Life in 1965.

It has been reprinted and repeated, held up as science fact and disparaged as the march to Godless evolution.

Both interpretations are wrong.

In reality, the Road to Homo Sapiens is no more scientifically correct than this version:

Homersapien

The evolution of modern humans was not an all-in-line march to the finish as the famous  March to Progress illustration implies.

Modern humans sit on one tip of a branch of an ancient human family tree – a tangled tree with many branches.

All of the other branches in this tangled tree have died out. We alone survive.

But in the not-so-far past (relatively speaking), this was not the case. In the past, modern humans shared our planet with some of the now extinct branches of our tangled family tree.

Last to leave, last to arrive

Modern humans have lived longer in Africa than any other place on earth – about 200,000 years.

Many modern humans stayed in Africa. Other groups of modern humans left Africa about 70,000 years ago and spread across Europe, Asia, the Pacific, and the Americas (see map).

But modern humans were late to the out-of-Africa party.

An ancestor of modern humans had already ventured out of Africa 500,000 – 600,000 years before. Once out of Africa, this ancestor group further split into at least two important groups: the Neanderthals and the Denisovans. The members of the ancestral group that remained in Africa gave rise to modern humans.

The Neanderthals spread out across Europe and western Asia and the Denisovans ranged from eastern Europe to eastern Asia. When modern humans finally moved out of Africa and trekked across the globe, they met some very ancient cousins. But by 30,000 years ago, modern humans stood alone – the last remaining branch on the tangled human family tree.

All three human groups (Neanderthals, Denisovans, modern humans) are distinct – some scientists consider them different species. However, modern humans were closely related enough to mate and have children with the other two groups.

How do we know this?  People with European and Asian ancestry have trace amounts (one to two percent) Neanderthal DNA in their genomes. Denisovan DNA is highest in the modern populations of southeast Asia and Oceania (4 – 6%). Trace amounts of Denisovan DNA are also found in east Asian populations. Interestingly, people in sub-Saharan Africa have zero-to-almost zero Neanderthal or Denisovan DNA.

Denny

An extraordinary new discovery tells us that early human groups also mated with each other.

For the last twelve years, a single cave in Siberia has produced important discoveries of Denisovan remains. The Denisova cave (for which this group was named) yielded an astonishing new find, first announced in August 2018.

A bone from a thirteen-year-old girl was found with equal amounts of Denisovan and Neanderthal DNA.

Humans have 23 unique chromosomes. But – we have two copies of each chromosome, one from biological mom and one from biological dad.

The chromosomes of the 13 -year old girl found in the Denisovan cave (nicknamed “Denny”) stunned scientists. In each chromosome pair, one chromosome came from a parent that was exclusively Neanderthal and one came from a parent that was exclusively Denisovan.

Additionally, humans have a tiny bit of DNA in the mitochondria of their cells. All mitochondrial DNA comes from mom (I wrote about mitochondrial DNA in this post). Denny’s mitochondrial DNA was Neanderthal.

It was as if we had a front-row seat. Denny was a first-generation offspring of a Neanderthal mom and a Denisovan dad.

The first reaction of the researcher studying Denny’s DNA was “what did I do wrong?”. The tests were repeated six times, and each time the results were the same.

Denny is an exciting, but not surprising find. We have indirect evidence of interbreeding: trace amounts of DNA from “cousin” human groups have been found in Neanderthals, Denisovans, and modern humans. With the discovery of Denny, we have direct evidence of interbreeding between human groups. How often did that happen? That’s a question to be answered, but Denny provides a hint. We’ve only known about Denisovans since 2008, and already we have a first-generation hybrid with another human group. We have yet to find a first-generation offspring of modern humans and Neanderthals or Denisovans, but they surely existed.

Screen Shot 2018-12-28 at 4.32.01 PM

Do you have more questions about the tangled human family tree? Here’s a link to an excellent six-minute animated graphic Last Hominin Standing: Charting Our Rise and the Fall of Our Closest Relatives.

*****

And as You speak
A hundred billion creatures catch Your breath
Evolving in pursuit of what You said
If it all reveals Your nature so will I

(Hillsong United “So Will I“)

*****

IMG_1320

Science or Faith – Do We Have to Choose?

For the last few months, I have been blogging through The Language of Science and Faith by Karl W. Giberson and Francis S. Collins. Each chapter in the book addresses a FAQ about the Genesis account of creation and scientific evidence regarding the origins of the universe and life on earth.

Each post in the series tackled a chapter question, with my comments and discussion.

What do you think?

Here are links to all of the posts in this series – did you miss any?

Jesus-fish-Truth     Introduction 

joe mendi pic     Do I Have to believe in Evolution?

dinos on ark       Can We Really Know the Earth is Billions of Years Old?

541156-darth-vader-luke-skywalker        How Do We Relate Science and Religion?

Scottish_paper      Can Scientific and Scriptural Truth Be Reconciled?

640px-Lisa_on_the_witness_stand      Science and the Existence of God

teach_the_controversy_by_ex_leper-d2xgnki      Why is Darwin’s Theory So Controversial?

sherlock_holmes      What is the Fine-Tuning of the Universe, and How Does it Serve as a Pointer To God?

octopus wearing glasses     Evolution and Human Beings