Genetics, Aging and Environment

 “Age is just a number and mine is unlisted,” says the actor in the TV commercial for the high protein nutritional drink. We age differently, so some might count age as only a number. But don’t rush to discount age. A recent study showed age often plays a greater role than genetics in gene expression and susceptibility to disease.

TV commercial in which actor says, “Age is just a number and mine is unlisted” (from www.ispot.tv/ad/nHX8/boost-high-protein-age-is-just-a-number).

Welcome back. Let me jump right in with the oldest evolutionary explanation for biological aging. On 6 December 1951, Peter Brian Medawar presented an inaugural lecture at University College, London, titled “An Unsolved Problem of Biology.” He proposed the mutation accumulation theory of aging.

Medawar’s theory is based on the idea that the force of natural selection ebbs with age as individuals are less likely to reproduce and contribute their genetic information to the next generation. As reproduction ceases, the weaker force of natural selection cannot consistently eliminate harmful mutations, which then accumulate and lead to the evolution of aging.

Genetics vs. Aging
Now, let me jump to the recent study I mentioned in the opening. A team of researchers affiliated with the University of California, both Berkeley and Los Angeles, investigated the relative effects of genetics, aging and environment on how some 20,000 human genes are expressed. The researchers built a statistical model using data on 27 different human tissues available from nearly 1,000 people. (If you’re feeling a bit lost about tissues and genes, “Tissues” under P.S. below might help.) 

Four types of tissue (graphic prepared by A.D.A.M Images; figure from medlineplus.gov/ency/imagepages/8682.htm).

The team found that genetics mattered about the same amount across the tissues, not playing more of a role in one tissue or another.

The impact of aging, however, varied more than twentyfold among the tissues. Whether blood, colon, arteries, esophagus or fat tissue, age plays a much stronger role than genetics in driving gene expression patterns.

Outlier Tissues
The researchers also found that Medawar’s theory did not hold for all 27 tissues. Evolutionary important genes were expressed at higher levels in older people in five types of tissues. What’s different about these tissues is that they constantly turn over throughout our lifespan. Because blood, for instance, has to proliferate for us to live, these genes have to be turned on late in life.

Every time these tissues replace themselves, they risk creating a genetic mutation that can lead to disease. And these five tissues do produce the most cancers.

Trends in Cancer: the evolution of lifespan and age-dependent cancer risk (from
www.cell.com/trends/cancer/fulltext/S2405-8033(16)30121-2). 

The study indirectly indicated the effect of environment--air, water, food, exercise; the impact of everything other than age and genetics. The researchers judged that environment accounts for up to one-third of the changes in gene expression with age.

Wrap Up
The results underscore that, while our genetic makeup can help predict gene expression when we are younger, it is less useful in predicting which genes are ramped up or down when we’re older (being older than 55 in the study). Identical twins have the same set of genes, yet as they age, their gene expression profiles diverge, and the twins can age very differently from one other.

The findings have implications for efforts to correlate diseases of aging with genetic variation. The study’s senior researcher suggests that perhaps these efforts should focus less on genetic variants that impact gene expression when pursuing drug targets.

So, give age due diligence, and thanks for stopping by.

P.S.
Mutation accumulation theory of aging
books.google.com/books/about/An_Unsolved_Problem_of_Biology.html?id=ozEmPQAACAAJ
en.wikipedia.org/wiki/Mutation_accumulation_theory
Study of tissue impacts of aging and genetics in Nature Communications journal: www.nature.com/articles/s41467-022-33509-0
Article on study on EurekAlert! website: www.eurekalert.org/news-releases/967253

Tissues (from medlineplus.gov/ency/imagepages/8682.htm and training.seer.cancer.gov/anatomy/cells_tissues_membranes/tissues/)
Cells are the building blocks of all living things, and genes are inside almost every cell in our bodies. Tissues are groups of cells that have similar structure and that function together as a unit. There are four basic types of tissue: connective tissue supports other tissues and binds them together (bone, blood and lymph tissues); epithelial tissue provides a covering (skin, the linings of passages inside the body); muscle tissue includes striated muscles that move the skeleton and smooth muscle, such as the muscles that surround the stomach; nerve tissue is made up of nerve cells (neurons) and carry "messages" to and from parts of the body.

Journalists and Science Cons

Welcome back. Being an impatient news junkie, I’m always bothered by journalists giving both sides of an issue when one side is utter nonsense or lies. Oh, this isn’t about Trump, though it could be; this is about reporting on science--climate change, vaccinations, evolution, etc.

Robert F. Kennedy Jr. has become a major figure in the anti-vaccine movement. I remember his father well, but is it really necessary to cover Bobby’s son? (photo from CNN video, www.cnn.com/2022/01/24/politics/robert-kennedy-jr-anti-vaccine-nazis-what-matters/index.html).

In my corner are two philosophy professors, one affiliated with Illinois Institute of Technology, the other with Florida State University. They agree that journalists need not cover both sides when one side is advancing a con.

In fact, they’ve published a paper that compares and contrasts a financial con, which aims to separate people from their money, with an epistemic con, which aims to recruit people to spread doubt and falsehood about well-established claims. (Epistemology is the study of knowledge.)

Epistemic Cons
An epistemic con starts when facts emerge that threaten a powerful group (say, tobacco companies or Big Oil). They disseminate plausible but dishonest arguments to persuade you to doubt or reject the facts. The epistemic con artist really succeeds if you try to convince others, even if it’s just doubt.

What #ExxonKnew vs what #ExxonDid, graphic by John Cook, SkepticalScience.com (from www.theguardian.com/environment/climate-consensus-97-per-cent/2018/mar/23/in-court-big-oil-rejected-climate-denial).

So, don’t open your wallet to financial cons and don’t open your mind to epistemic cons. Alas, the only way to avoid falling for an epistemic con is to never trust anyone, which is no way to live. That’s why the first rule of avoiding the con is to admit you’re vulnerable. Trust sources with more reliable track records, don’t trust sources with less reliable track records.

“Settled science,” confirmed by an array of scientific subdisciplines, deserves your trust. Evolution for example, can be confirmed by the fossil record, biogeography, stratigraphy, genetics, anatomy and more.

Cons Against Settled Science
Con artists try to wow us with magic bullet arguments, most of which are dishonest, deeply confused or both. Those arguments generally follow the same themes, such as Obvious Counterexamples, e.g., global warming implies we won’t have cold snowy days in winter; Cherry Picking, e.g., 50 years ago, scientists said the Earth was cooling; or Biased Scientists, e.g., scientists believe evolution because they’re atheists.

Magic bullet arguments aren’t always easy to debunk. Yet even when they make a good point, there is no single piece of evidence on which settled science rests that can be unraveled by a magic bullet.

How do con artists open your mind to these arguments? They appeal to your epistemic virtue: You’re fair. You’re open-minded. You’re smart. Think for yourself. 

Epistemic Virtue: Have the courage to use your own understanding, by German philosopher, Immanuel Kant, born Emanuel Kant, 22 April 1724 – 12 February 1804 (from en.wikiquote.org/wiki/Epistemic_virtue#/media/File:Kant5.jpg).

Unfortunately, there’s a difference between epistemic virtue and epistemic vanity. Con artists rely on our inability to tell the difference. They rely on our overconfidence.

You think the game is figuring out the truth. The real game is to see how long the con artist can string you along. While you’re debunking one magic bullet argument, you’re being fed more.

Can You Avoid Being Conned?
Your best bet to avoid being conned on settled science is close-minded deference, which allows no room for doubt unless doubt arises within science itself.

If you’re going to consider magic bullet arguments, do so with a closed mind. Treat them as interesting puzzles or as material for exploring bad reasoning.

We fall for epistemic cons for the same reason we fall for financial cons: We trust the wrong people. More, it’s that overconfidence in our ability to figure out the truth.

Wrap Up
Even if journalists close their minds to the con, they may report facts in a way that opens their audience’s minds to the con. Reporting or not reporting fake controversies both seem to play into the con artist’s hand.

Those authors in my corner find only one technique for helping readers avoid confidence games: Tell the story of the epistemic con, how it works. Most people accept the story, at least applied to others.

The challenge comes if journalists apply the story to their readers. Expect loud and angry blowback. The villain of the story is our harsh judgments of those who’ve fallen for the con; our offended dismissals of anyone who suggests that we’ve been conned.

But the story of the epistemic con gives us the opportunity to recognize what our role in the story has been and to choose our role going forward.

Thanks for stopping by.

P.S.
Study of epistemic cons in science reporting in Frontiers in Communication journal: www.frontiersin.org/articles/10.3389/fcomm.2021.545429/full
Articles on study on Illinois Tech news and EurekAlert! website:
www.iit.edu/news/alternative-facts-are-cons-philosophers-paper-argues-and-journalists-can-help-quash-them
www.eurekalert.org/news-releases/956020

Accepting Evolution

Welcome back. Although creationism and intelligent design proponents are going strong, a majority of American adults now accept evolution. At least that’s what researchers with the University of Michigan, National Center for Science Education and Spain’s University of Oviedo found through analysis of national surveys from 1985 to 2020.

To be sure we’re on the same playing field, I’ll define some terms and review the status, then get back to the researchers’ analysis.

Evolution, Creationism, Intelligent Design from Merriam-Webster
Evolution is the scientific theory that explains the development of new species and varieties of living things from preexisting forms through the action of biological mechanisms (e.g., natural selection, genetic mutation or drift, and hybridization).

Creationism is a doctrine or theory that matter, the various forms of life and the world were created by God out of nothing, usually in the way described in Genesis.

Creationism versus evolution (graphic by Sidney Harris from
www.lockhaven.edu/~dsimanek/philosop/creation.htm).

Intelligent design is the theory that matter, the various forms of life and the world were created by a designing intelligence.

Science or Religion?
Creationism took a hit in 1987 when the U.S. Supreme Court ruled against a Louisiana law that required “creation science” be taught in public schools where evolutionary science was taught (Edwards v. Aguillard, 482 U.S. 578). In support of Aguillard, 72 Nobel Prize-winning scientists, 17 state academies of science and 7 other scientific organizations filed amicus briefs that described creation science as being composed of religious tenets.

But the hit was far from fatal. Although no state currently bans teaching evolution, Oklahoma makes it optional, Louisiana and Tennessee give the freedom to question scientific theories like evolution, and about 20 states still allow creationism to be taught.

The intelligent design movement arose out of the creation science movement. Its chief activities are promoting awareness of the intelligent design concept, lobbying policymakers to include it in high school science, and legal actions to defend or remove barriers to it being taught.

Intelligent design’s scientific material has been criticized as containing factual misrepresentation and misleading, rhetorical and equivocal terminology. Scientists responding to a poll overwhelmingly said intelligent design is about religion, not science. The National Academy of Sciences stated that creationism and intelligent design are not science because they cannot be tested by scientific methods.

In contrast, evolution is one of the most substantiated theories in science, backed by such disciplines as geology, paleontology, genetics and developmental biology. Like other scientific theories (e.g., gravity), evolution does not address God or religious belief. A 2009 Pew Research Center survey of scientists found 97% accept evolution and 51% believe in God or a higher power.

Surveying Evolution’s Acceptance
The researchers’ analysis of evolution’s acceptance was based on a mix of national surveys. Since 1985, several years of biennial National Science Board surveys, several national surveys funded by other units of the National Science Foundation, and a new time series focused on civic scientific literacy funded by NASA have asked U.S. adults to agree or disagree with the statement, “Human beings, as we know them today, developed from earlier species of animals.”

While survey results during the two early decades were generally split, acceptance of evolution increased significantly during the last decade. The percentage of U.S. adults agreeing with the statement increased from 40% to 54%, which reflected a small decrease in overt rejection and a larger decrease in those unsure about evolution.

Response of U.S. adults, from 1985–2020, to the statement, “Human beings, as we know them today, developed from earlier species of animals" (from journals.sagepub.com/doi/abs/10.1177/09636625211035919?journalCode=pusa).

Through statistical analysis (structural equation modeling) of the combined data set, the researchers were able to attribute the increased acceptance of evolution to higher enrollment in baccalaureate-level programs, exposure to college-level science courses, a declining level of religious fundamentalism and a rising level of civic scientific literacy.

Wrap Up
The rise in evolution’s acceptance in the U.S. is certainly significant, however 54% is likely to still be low for a developed nation. By “still,” I’m referring to a 2005 study of evolution’s acceptance in 34 developed nations. Only one nation, Turkey, scored lower than the U.S.

Response of adults in selected countries in 2005 to the statement, “Human beings, as we know them, developed from earlier species of animals” (graphic from en.wikipedia.org/wiki/Level_of_support_for_evolution modified from data on 34 countries, 1985-2005, www.science.org/lookup/doi/10.1126/science.1126746).

Nevertheless, if the factors identified by the researchers as affecting the increased acceptance are correct, acceptance in the U.S. should keep rising. Thanks for stopping by.

P.S.
Study of U.S. acceptance of evolution, 1985-2020, in Public Understanding of Science journal:
journals.sagepub.com/doi/abs/10.1177/09636625211035919?journalCode=pusa
Article on study on EurekAlert! website: www.eurekalert.org/news-releases/925987
U.S. Supreme Court case Edwards v. Aguillard, 482 U.S. 578 (1987): en.wikipedia.org/wiki/Edwards_v._Aguillard
Intelligent design movement: en.wikipedia.org/wiki/Intelligent_design_movement
Teaching of evolution, 2021: worldpopulationreview.com/state-rankings/states-that-dont-teach-evolution
Pew Research Center survey: www.pewresearch.org/politics/2009/07/09/section-4-scientists-politics-and-religion/
Example of National Science Board reports: ncses.nsf.gov/pubs/nsb20207/public-familiarity-with-s-t-facts