genetic drift

[aj]

I'm not sure that I completely under stand genetic drift,......BUT. Here in my area we have what is considered a round up resistant weeds. After fields were sprayed year after year some plants that were initially killed by the chemical became resistant to the herbicide. We were discussing this down at the coop the other day. One guy claimed that this process occurred because environment changed the plant over the years. I argued that over time and billions of kochia plants......one plant had a slight mutation and survived.....made seed.....and then started producing the round up ready resistant plant seed. That the environment of the spraying did not change the dna of the plant but the process was that genetic drift occurred and this mutated plant survived the enviroment of the spraying. Am I right or wrong?

 

[aj]

In other words....the mutation that allowed the plant to be immune from the effect of the chemical could have happened in a "vacuum" and it was not because of repeated spraying.

 

[shortybreeder]

If I understand you correctly, then yes, probably. Sort of like those disinfectant sprays that kill 99.9% of bacteria. By killing all of the surrounding bacteria you eliminate the competition for the .1% and then those genes reproduce at a greater rate creating a strain that is "resistant." Now it is possible that the environment changed them, but more likely it is simply an accidental artifical selection for Roundup Resistant weeds.

 

[knabe]

you could start here.


https://en.wikipedia.org/wiki/Genetic_drift

 

[r.n.reed]

A.J. you have a lot deeper discussions at your ''Elevator Meetings'' than we do.I'm jealous.

 

[aj]

I'm an amateur anthropologist so the genetic drift occurs everywhere. Did the bison bison drift down from the bison antiquous? What about skin color in humans? Some races also have bunched up blood types. Have certain people survived say the plague because they were lucky or did they have just a little different genetic wrinkle? Do certain people or say the native americans have more alcohol problems than other. On and on. What about cattle? Then of course you get into the age of the earth and the biblical science and etc.

 

[HerefordGuy]

I'm not sure that I completely under stand genetic drift,......BUT. Here in my area we have what is considered a round up resistant weeds. After fields were sprayed year after year some plants that were initially killed by the chemical became resistant to the herbicide. We were discussing this down at the coop the other day. One guy claimed that this process occurred because environment changed the plant over the years. I argued that over time and billions of kochia plants......one plant had a slight mutation and survived.....made seed.....and then started producing the round up ready resistant plant seed. That the environment of the spraying did not change the dna of the plant but the process was that genetic drift occurred and this mutated plant survived the enviroment of the spraying. Am I right or wrong?

The concept is correct, the term you are using is not. Natural selection, not genetic drift, is leading to herbicide resistance.
I found these helpful:
http://www.popsci.com/science/article/2010-05/roundup-resistant-superweeds-invade-us-fields
https://www.geneticliteracyproject.org/2014/10/01/superweeds-confirm-failure-of-gmos-or-maybe-not-narrative-misleads-avoids-real-solutions/

 

[WinterSpringsFarm]

Here is my 2 cents, worth exactly what you are paying for it. While I haven't ran into any real resistant weeds in my crop operation I do my fair share to avoid it.

I feel Glyphosate Resistance has come from A) over use of the product and B) off label use. Not using proper tank mixes such as adjuvants or mix partners. And cheap farmers trying to use the minimum rate. What this does is ding a plant while not killing it. Making this plant more resistant, and its seeds even more resistant. Trying to use round up again to kill it only makes it worse and eventually leads to glyphosate resistance.

I use different chemistry yearly, I use several tank mix partners, and I use full label rates to ensure I get a good solid kill on the first go around. So far we have some plants that don't kill easily with glyphosate, but that's what the other tank partners are for.

 

[aj]

Winter Spring Farms......you are 100% right. Out here.......farmers were using half rates.......they had to buy their own sprayers to get this done. I am a capitalist but this is a argument against the capitalist system. Farmers were cash renting and undercutting each other(because they thought they were pulling a fast one) and it is a hell of a mess out here.

 

[MDitmars]

Aj you are bringing up mechanisms of evolution. There are four major mechanisms (mutation, migration, genetic drift, and natural selection).

To figure out what is keeping weeds alive you have to test each mechanism to see if it holds true in our situation.

At first glance we can rule out migration and genetic drift, which leaves mutation and natural selection. I tend to believe natural selection over mutation. I haven't looked up any true research to see what round up actually does to a plant not resistant(If it kills or simply suppresses or both). I would think for a mutation to occur you would need the plant to survive round up or for the mutation to have existed before the initial spray leading into natural selection of the mutated plant.

All four mechanisms can attribute to the propagation to the resistant strand in my understanding but some or less likely to the initial resistance.

In the event incorrect use of sprays are triggering a mutation to a weakened plant it would be difficult to test this idea. Roundup has been around since 1974 you would have to discover where the first reports of resistance were seen. Are these first resistances systematically spreading?

Here is a link to Berkeley's informational website.
http://evolution.berkeley.edu/evolibrary/article/evo_14

 

[aj]

One out of 5 billion kochia plants has a slight mutation or or slightly different genetic wrinkle. The one plant survives a half rate application of chemical. Out here the Russian thistle or tumble weed also has beat the human race. The plant goes to seed.......blows across fields....scatters seed across fields......you can literally seed.....the next spring from this happening. You can see where the tumble weed blew out across the field. I realize that to alot of people no one exists west of the Missouri river but they do. And we have agriculture out here in some isolated spots. It is currently snowing here in Goodland Ks but no one would believe that also. The mutation causes a genetic drift. Its not natural selection in this case cause the brilliant human race is involved with this process.

 

[knabe]

capitalism penalizes what you are implying is capitalism.

 

[aj]

Native Americans.......lack of facial hair.....truth or myth.......genetics? African Americans with red hair.......is this from some slave plantation owners genetics or is this something else? Has there ever been a polled buffalo?

 

[knabe]

Lessons today by aj, the coop savant.


Snow drifts cause mutations in plants which cause facial hair on aj, but not others.

 

[MDitmars]

Aj Berkeley gives a layman's definition to genetic drift in that it is a plant by sheer chance has more offspring survive and that they have no more defense mechanisms than any other. and I am pretty sure that is what Knabe is giving you crap for right now is miss use of terms. "So although genetic drift is a mechanism of evolution, it doesn't work to produce adaptations."-Berkley

Migration would attribute to the spread of genetic resistant plants...

There is not a record for when the initial mutation occurred. We don't know if it occurred in response to the spray or at some earlier point in history. Human selection (and i do stand corrected on that one) is what allowed these genetically resistant plants to survive.

http://evolution.berkeley.edu/evolibrary/article/evo_24

 

[knabe]

I'm not sure that I completely under stand genetic drift,....

it's really easy. it's the phenomena used to describe the further and further you are away from making some decent shorthorns that don't have maine or red angus or some other breed in them.

 

[Jive Turkey]

I'm not sure that I completely under stand genetic drift,....

it's really easy. it's the phenomena used to describe the further and further you are away from making some decent shorthorns that don't have maine or red angus or some other breed in them.

Can you quit be an a-hole every time aj posts something?

It's getting really old and petty.

 

[aj]

Why do African Americans have a higher level of high blood pressure......and at an earlier age. Is it genetic?

 

[stithka]

I read on here often. I rarely post.

I agree with Jive Turkey. It is getting old Knabe.

AJ starts some interesting conversations. You simply insult others.

Additionally, some of the information you post is outdated or not backed by good science. Maybe if you were a little less confrontational there would be more discussion and less bickering.

Thank You.

 

[shortybreeder]

Why do African Americans have a higher level of high blood pressure......and at an earlier age. Is it genetic?

Sociologists attribute it to increased stress from discrimination. The fact that they wake up every morning and have to worry about if a cop is going to pull them over due to their skin color, or if people are going to harass them in the streets.