Category Archives: Genetics

What Did Corn, Watermelon, and Peaches Look Like Thousands of Years Ago?

Posted on June 1, 2015 | Comments Off on What Did Corn, Watermelon, and Peaches Look Like Thousands of Years Ago?

The answer is at an article at Vox. In brief, they didn’t look like anything you’d recognize today, thanks to selective breeding. That’s also why most of us today  can’t eat a true Paleolithic diet. Regarding corn:

As maize became domesticated in Mesoamerica, it was radically altered through selective breeding. Early farmers would examine their plants and save the seeds of those that were larger or tastier, or whose kernels were easier to grind. By 4000 BC, cobs were already an inch long. Within just a few thousand years, cobs had grown to many times that size. Later on, plant hybridization became an important breeding method to further cultivate certain traits.

Click through for well-done infographics.

 

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Posted in Genetics

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Random Thoughts On Fitness

Posted on November 21, 2012 | 2 comments

A couple years ago, I was thinking about putting together a fitness program for myself.  My goals were endurance, strength, less low-back aching, flexibility, longevity, and being able to get on my horse bareback without a mounting block or other cheat.

I spent quite a bit of time at Doug Robb’s HeathHabits site.  He has a post called The “I don’t have time to workout” Workout.  I ran across some paper notes I made during my time there.  Doug recommended some basic moves to incorporate: air squat, Hindu pushup, dragon flag, shuffle of scissor lunge, Spiderman lung, hip thrust/bridge, swing snatch, dumbbell press, Siff lunge, jumping Bulgarian squat, band wood chops, stiff leg deadlift.  Click the link to see videos of most of these exercises.  The rest you can find on YouTube.

Another post is called “Do you wanna get big and strong? -Phase 1”.  The basic program is lifting weights thrice weekly.  Monday, work the chest and back.  Tuesday, legs and abs/core.  Friday, arms and shoulders.

  • Chest exercises: presses (barbell or dumbell, incline, decline, flat, even pushups with additional resistance  – your choice
  • Back: chins or rows
  • Legs: squats or deadlifts
  • Arms and shoulders: dips, presses, curls

Doug is a personal trainer with a huge amount of experience.  He’s a good writer, too, and gives away a wealth of information at his website.

Around this same time of searching a couple years ago, I ran across Mark Verstegen’s Core Performance, Mark Lauren’s book “You Are Your Own Gym,”  and Mark Sisson’s free fitness ebook that also  features bodyweight exercises. Lauren is or was a Navy Seal trainer.  His plan involves 30 minutes of work on four days a week and uses minimal equipment.  Lots of good reviews at Amazon.com.

I did the Verstegen program for 15 weeks and saw major improvements in my fitness and low-back aching.  It’s a good program.  The only drawback is that it required six hours a week of my time.

Newbies to vigorous exercise should seriously consider using a personal trainer.

If you’ve had any experience with these regimens, please share.  Or is there another you like?

Steve Parker, M.D.

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Posted in Exercise, Genetics

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Ancestral Diet May Improve Diabetes in Pima Indians

Posted on November 1, 2012 | 2 comments

Saguaro cactus fruit is edible

I ran across a 1991 New York Times article by Jane Brody discussing the benefits to Pima Indians of returning to their ancestral diet.  The Pima have major problems with obesity and diabetes.  (I frequently treat Pima Indians in the hospital.)  Some quotes:

Studies strongly indicate that people who evolved in these arid lands are metabolically best suited to the feast-and-famine cycles of their forebears who survived on the desert’s unpredictable bounty, both wild and cultivated.

By contrast, the modern North American diet is making them sick. With rich food perpetually available, weights in the high 200’s and 300’s are not uncommon among these once-lean people. As many as half the Pima and Tohono O’odham (formerly Papago) Indians now develop diabetes by the age of 35, an incidence 15 times higher than for Americans as a whole. Yet before World War II, diabetes was rare in this population.

Pima Indians traditionally ate a diet of tepary beans, mesquite seeds, corn, grains, greens, and other high-fiber/low-fat foods.  The switch to a diet high in sugar, refined grains, and other highly processed convenience foods may well be responsible for the current high rates of obesity and diabetes.  Australian aborigines have the same problem.

Steve Parker, M.D.

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Posted in Genetics, Grains, Overweight, Paleo Diet

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Alex Hutchinson on the Paleo Lifestyle

Posted on December 5, 2011 | 5 comments

Fleas from rats spread Yersinia pestis to humans

Alex Hutchinson has a recent article in Canada’s The Globe and Mail on the potential health benefits of the paleo lifestyle.  His conclusion:

So will going paleo really pay off with better health? As a big-picture guide to how to organize your life, definitely. But don’t get carried away with trying to recreate the exact details of a long-lost diet. Humans have changed and diversified even over the past few thousand years, so the only way to know what works best for your genes is to experiment. Go wild.

The article mentions the “increasing pace of human evolution,” an idea I’m still not convinced is valid.  Sure, a large population of critters should produce more genetic variation and mutation.  But it could take longer for a successful variation to spread through that population, compared to a smaller population.  It depends on selection pressure, to some extent.  The Black Plague in 14th century Europe changed that population quicker than any single genetic mutation I know of.  It wiped out 40% of the population.  Were those who survived genetically different from those who died?

I have much respect for Alex’s thoughts on exercise.  He usually puts more research and thought into his writing.  Check out his Sweat Science blog.

Steve Parker, M.D.

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Posted in Evolution, Genetics, Paleo Theory

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Free Online Paleoanthropology “Textbook”: John Hawks Blog

Posted on October 25, 2011 | 4 comments

I’ve never seriously studied anthropology, paleontology, or paleoanthropology.  When I read someone who seems or claims to be an expert on paleoanthropology or certain aspects of evolution, it requires a degree of trust on my part. 

(I have a stronger background in evolution, thanks to a B.S. degree in Zoology.  I was thoroughly indoctrinated in the mid-1970s.)

It was a slow day at work, so I just spent a couple hours perusing the blog of an actual paleoanthropologist named John Hawks.  It’s a massive database that may be the equivalent of a paleoanthropology textbook.  Naturally, it will reflect the biases of the author, if any (and we all have some, don’t we?) . 

Some interesting things you’ll find there:

Regarding the pace of human evolution in the Neolithic period, Artemis P. Simopoulos (with The Center for Genetics, Nutrition and Health in 2009) has a different view:

The spontaneous mutation rate for nuclear DNA is estimated at 0.5% per million years.  Therefore, over the past 10,000 years there has been time for very little change in our genes, perhaps 0.005%.  In fact, our genes today are very similar to the genes of our ancestors during the Paleolithic period 40,000 years ago, at which time our genetic profile was established.

I dunno; you decide.

Steve Parker, M.D.

Reference:  Simopoulos, Artemis P.  Evolutionary aspects of the dietary omega-6:omega-3 fatty acid ratio: medical implications.  World Review of Nutrition and Dietetics, 100 (2009): 1-21. Epub August 17, 2009.

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Posted in Genetics, Paleo Theory

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