Not really no… even from a “single” cell point of view they inherit different biological junk that floats in the extracellular fluid of the mother (forgot the name, probably transcription factors). Also you should specify homozygote twins cuz twins can be of different sex! Anyhow… they share all DNA 100% but that doesn’t make them “the same”. Even in utero they might be exposed to different, albeit.small, stimuli. Maybe one is receiving slightly more nutrients bc he’s attached first etc etc. Life is so complicated that there’s many different things that can change! So then after birth they will still be exposed to similar but not identical environments and stimuli. They will eventually diverge and can, and do, become very different individuals, even from a mere biological pov.
I’m learning so much in this thread! So even in the womb, there exists different stimuli that can affect gene expression in identical homozygous twins? What other kinds of stimuli could that consist of? I know you said difference in absorbed nutrients, but what other things can affect gene expression? Changes in pressure? like for example, could the mom sleeping on one side for a certain duration of time cause changes in blood flow to the fetuses, etc? Thanks for putting up with all my questions, haha
It’s not very scientific of me to make these claims, I apologize. I’m not an expert in fetus development… I’m not sure these differences of stimuli matter in womb so much as to affect gene expression, but we can’t really exclude them, can we? That’s what I’m getting at. To be identical, these twins must undergo an identical development, which is impossible.
Not really no… even from a “single” cell point of view they inherit different biological junk that floats in the extracellular fluid of the mother (forgot the name, probably transcription factors). Also you should specify homozygote twins cuz twins can be of different sex! Anyhow… they share all DNA 100% but that doesn’t make them “the same”. Even in utero they might be exposed to different, albeit.small, stimuli. Maybe one is receiving slightly more nutrients bc he’s attached first etc etc. Life is so complicated that there’s many different things that can change! So then after birth they will still be exposed to similar but not identical environments and stimuli. They will eventually diverge and can, and do, become very different individuals, even from a mere biological pov.
I’m learning so much in this thread! So even in the womb, there exists different stimuli that can affect gene expression in identical homozygous twins? What other kinds of stimuli could that consist of? I know you said difference in absorbed nutrients, but what other things can affect gene expression? Changes in pressure? like for example, could the mom sleeping on one side for a certain duration of time cause changes in blood flow to the fetuses, etc? Thanks for putting up with all my questions, haha
It’s not very scientific of me to make these claims, I apologize. I’m not an expert in fetus development… I’m not sure these differences of stimuli matter in womb so much as to affect gene expression, but we can’t really exclude them, can we? That’s what I’m getting at. To be identical, these twins must undergo an identical development, which is impossible.