Looking for evolutionary info on how smells can be carried on DNA (page 2)

DATA-DOG

Huh?? I thought this was a Science topic? I'm not trying to disrupt your thread on porpoise.... ( Rim-shot!!! )

DD

cofty

how does the DNA carry a smell which is not part of the body from one generation to the next - Crabs

First you need to provide evidence that it does. I have serious doubts. Please link to a source.

Experiences can have an effect on future generations through a process called methylation. It is like a temporary switch that regulates the expression of genes.

Trust me, there is no book that you can read that answers this question - Crabs

I don;t trust you at all. Methylation is described in lots of books and hundreds of papers. You could start with "The Epigenetics Revolution" by Nessa Carey

Crabby: The genetics of smell is pretty worked out as I wrote on the other thread. We know how the smell receptors arise genetically, and also a bit about how the neural coding of the smells arise in for instance flies. You can read more here:

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

What bit is it precisely you question? (i.e. the genetics of the smell receptors or the neural coding?).

sir82

how does the DNA carry a smell

What a bizarre question. You seem to think that somehow an odor attaches itself to the literal double helix.

As Cofty explained above, the DNA carries instructions on how to build a brain which knows what to do when it registers a certain odor.

Crabby

To all, I know it sounds incredible, but it happens. How no one knows,

http://www.scientificamerican.com/article/fearful-memories-passed-down/

http://reset.me/story/science-proving-memories-passed-ancestors/

on February 20, 2015

Do you have a fear of spiders? Maybe snakes? It could be your ancestors trying to tell you something. Recent studies have provided evidence that memories of fear are one of many things our forebearers pass down to us through our DNA.

A 2013 study from Emory University found that mice trained to fear a specific odor would pass their emotions on to their offspring and future generations. Scientists applied electric shocks to mice as they exposed them to the smell of cherry blossoms. The mice then bred, and both the children and grandchildren of the affected rodents demonstrated a fear of cherry blossoms the first time they smelled them.

“Our results allow us to appreciate how the experiences of a parent, before even conceiving offspring, markedly influence both structure and function in the nervous system of subsequent generations,” Dr. Brian Dias of the Emory University department of psychiatry said to the Daily Telegraph. “Such a phenomenon may contribute to the etiology and potential intergenerational transmission of risk for neuropsychiatric disorders such as phobias, anxiety and post-traumatic stress disorder.”

The study went beyond just observing a fear reaction. Scientists actually looked at the brains of the animals and found physical changes in the areas that process odors, and also found a marker on the odor gene of the mouse DNA.

The experiment worked even when the researchers used artificial insemination in place of allowing the mice to breed naturally. The scientists still aren’t sure how the fear imprint makes it into the sperm — whether the smell itself passes through the blood, or the brain processes the odor and sends its own signal.

cofty

I've answered your question - Methylation aka epigenetics.

Read a book

cofty

Crabs - The SA article contains the same answer I gave you. Epigenetics. Did you even bother to read your own source?

Crabby

Neither the article nor your book has any idea how the information is passed, you do not even know what epigenetics means.

Epigenetics is the study of heritable changes in gene expression (active versus inactive genes) that does not involve changes to the underlying DNA sequence — a change in phenotype without a change in genotype — which in turn affects how cells read the genes. Epigenetic change is a regular and natural occurrence but can also be influenced by several factors including age, the environment/lifestyle, and disease state. Epigenetic modifications can manifest as commonly as the manner in which cells terminally differentiate to end up as skin cells, liver cells, brain cells, etc. Or, epigenetic change can have more damaging effects that can result in diseases like cancer. At least three systems including DNA methylation, histone modification and non-coding RNA (ncRNA)-associated gene silencing are currently considered to initiate and sustain epigenetic change.[1] New and ongoing research is continuously uncovering the role of epigenetics in a variety of human disorders and fatal diseases.

You must have had your mind messed with by a cult or something.

sir82

I think Crabby is pretty much the ideal definition of "troll".

bohm

I am soooooooo stupid I am beginning to read the b's as p's lol.

Looking for evolutionary info on how smells can be carried on DNA

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