Showing posts with label genetics. Show all posts
Showing posts with label genetics. Show all posts

Thursday, January 19, 2023

Contrarians--Genetic?

 I've long experience with contrarians--my sister was one.  I lean that way myself.

I wonder whether it's genetic or cultural?  Do "tight" societies , presumably ones less welcoming of contrarians, have fewer, or any at all?  I'd assume there might be an evolutionary basis--seems as if the species could benefit by having a few around, just as it presumably benefits by having a few left handers around.  On the other hand, while I'm a confirmed right handers, I was able to train myself to use the mouse left-handed when I was getting carpal tunnel pains.

Friday, July 16, 2021

Surprising (to Me) Views on Heritability

 Below is the text of a recent tweet.  I found the data in the table surprising, since I had the impression that professors were generally disdainful of the possible influence of genes. I didn't dig into the details of the poll, so the sample might have been small and/or skewed, or maybe sociologists differ from professors in other fields.



 

Thursday, April 30, 2020

What About Dispersion Measures of Height

Scholars in recent years have researched heights of different populations, being dependent on the rare instances when a government recorded the heights of individuals and the records survived.  Economic historians have used the data to support hypotheses about the prosperity of societies at different times, on the theory that if height increases over time, it means the people are better fed and so can realize more of their genetic potential.

I find that interesting.  I may have mentioned previously on this blog occasions when I notice a group of individuals from different countries seeming to have the same height.  For example, soldiers in various Asian countries or dancers in different ballet groups. I'd add another group: Latino laborers in the US.  It seems these days most workers on road building/repairing or building construction are Latino, and visually there seems not be little variation in height.

I assume that the lack of variation reflects a restricted diet, that Latinos have  genes which would  permit same variability in height as other populations groups, given an abundant diet.  So with all that, I wonder whether any of the researchers have figured out the distribution of heights over the population.


Tuesday, December 31, 2019

The Validity of DNA Testing

Just received the "health" side of an ancestry.com DNA test.

Uniformly bland results, finding nothing which increases risk of anything (which is good, but they didn't cover the most significant area for me--Alzheimers--oh well).

The one correlation they did find is: increased likelihood of drinking coffee.

I'm rolling on the floor, laughing, since I've always drunk a lot of coffee.  These days I'm down to about 5 cups a day, about 2 of which are leaded.  I suspect if I had an obituary drafted by the group of people who have known me over the years, the lead sentence would be:  "Bill drank a lot of coffee..."

(On a more serious note, I'd be curious to see some statistics on the percentage of tests for different things actually show a result exceeding the average.  I suspect it's low, quite low, but because it's us and we worry about the bad stuff, a DNA test is an easy sell.)

Saturday, December 07, 2019

Abundance Enables Variation in Height?

One of the things I'm recurrently intrigued by, and have commented on in this blog, is the photograph of masses of people who have the same appearance.  Usually these days the photo is of North Korean dancers or military performing in unison.  (In older days it was the Chinese military.) Everyone is the same height and much the same physiognomy, though I'll quickly stipulate to a native of the country, everyone looks different, an individual.

The explanation I've heard for such uniformity, particularly of heights, is that when there are environmental constraints the phenotype is restricted, and the full potential of the genotype is not realized. But in an environment of abundance genes can exert their full influence. That could be an explanation why Americans come in such a variety of shapes and sizes and North Koreans don't.

I wonder: height and perhaps weight are the most evident characteristics, but are there other characteristics which are limited by the environment?  Certainly we know that the society means Shakespeare's sister never wrote a play, but that's not quite what I'm looking at.  Just a thought.


Tuesday, October 16, 2018

New Terms: Adult Orphans and Family Tree Completists

Learned two new terms today from reading Post and Times:

"Adult orphans".  This refers to those of us, including me and my wife, who are getting old with no children, no parents, and essentially no support network.  Applying a label makes the problem seem more concrete.  Personally, on the one hand I'm tempted to say: "you made your bed, now lie in it." On the other hand, which I almost always have available, it's a real problem for us, and we need to figure out how to deal with it, most likely by moving to an assisted living complex which includes nursing care.  BTW, googling the term results in 45,000  hits, so it's not that new.

"Family tree completists" is unique to the Times article on the ability of a site called "GEDmatch" to help identify suspects in a crime from their DNA by analyzing DNA matches from a database of relationships created by genealogical enthusiasts.  For a while I was one of these--deriving great pleasure from adding another set of (remote) cousins to my genealogy.  I still maintain an ancestry.com account, with a number of trees which someday I may return to

Sunday, September 27, 2015

The Sinister Side

My father was left-handed, though he wrote with his right, having grown up in the time when children were forced to change to the majority standard.  That's why this Post piece was interesting, looking at the distribution of lefties over time and modern lefties geographically.  But the best writing on the subject I've read is still "Right Hand, Left Hand", a book by Chris McManus, who runs a blog here.

McManus in his book gets into some basic things, like how do we determine handedness at the most elemental level, molecules and atoms.  (Left-handed sugar isn't absorbed by the body.)  I won't pretend to have followed all the explanations, but he also gets into driving on the left versus driving on the right, and the genetic and environmental influences on fetal development.

I

Sunday, July 06, 2014

Round Oak Rag Apple Elevation--Something Completely Different

We had registered Holsteins on our farm, which if I recall meant we had to send in registration papers which included either a sketch of the cow's markings or a photo.  I assume the data included the cow's ancestry.  And the vet who did the artificial insemination would discuss with dad which bull's semen to use, which one was popular, etc. etc.  I never really got into this aspect of the business, and it was a business--but I was aware of the strange names of the bulls, which leads to the title of this post.

Anyhow today, via Northview Valley blog, I get to the bull in the title.  He even has his own wikipedia page, although it's flagged as having problems.

Monday, February 27, 2012

Gaining and Losing Resistance

John Phipps quotes a rant about farmers misusing genetic technology here. 

It caused me to wonder about this:  suppose farmers start using compound A on weeds.  Over the years the weeds develop resistance to compound A.  So our marvelous chemical industry develops compound B, which farmers start using in place of compound A. Now if I understand how it works, because weeds are now growing and reproducing  in an environment where the gene(s) providing resistance to compound A no longer provide a competitive advantage, those genes should eventually be lost from the weeds' genetic makeup. (While the weeds are busily gaining resistance to compound B.)

What I wonder, assuming I've got the biology roughly correct, is how long it takes to lose the resistance: 2 generations, 12 generations, 22 generations, 122 generations?

Saturday, October 09, 2010

Externalities: Not Costs But Benefits

The economists define an externality as something which isn't captured in the price of the good or service. I usually notice externalities as costs: the pollution which is a by-product of the internal combustion engine, for example.  But there can also be benefits.  In the case of BT corn (corn genetically modified to produce a natural toxin which kills corn borers), farmers who buy and use BT corn seed benefit their neighbors who don't.  Turns out it's like vaccinations--vaccinate enough susceptible people in a group, and the unvaccinated benefit because the disease can't establish itself.

Thursday, November 06, 2008

What Is Moore's Law for Genomes?

Recently had a DNA test run by ancestry.com for genealogical purposes, so I'm following news on the genome side a bit more closely these days. In IT there's something known as Moore's law, which talks about the rate at which technology improves (doubling every 18 months). In genome decoding, there seems to be something similar going on, according to this Technology Review article:

  • first genome = $300 million
  • James Watson's genome = $1-2 million
  • Yoruba man's genome = $250,000