Recent comments in /f/askscience

Blissful_Altruism t1_ja0e8sn wrote

Reply to comment by [deleted] in Water on Earth is not Constant. Why ? by ItsDivyamGupta

> Rutherford had found out that the nucleus of the nitrogen atom could be disintegrated by firing fast alpha particles into nitrogen. He asked Blackett to use a cloud chamber to find visible tracks of this disintegration, and by 1925, he had taken 23,000 photographs showing 415,000 tracks of ionized particles. Eight of these were forked, and this showed that the nitrogen atom-alpha particle combination had formed an atom of fluorine, which then disintegrated into an isotope of oxygen 17 and a proton.

https://en.m.wikipedia.org/wiki/Patrick_Blackett

It is 100% possible but is an extremely, very very rare occurrence.

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Unicorn_Colombo t1_ja0e23x wrote

Reply to comment by whydontuwannawork in Would two people who look identical but who are not related have similar matching DNA? by OhMyThiccThighs

Yes. Phenotype is a function of genes. So p = f(g). Obviously, it depends on the function f. If the function was an absolute value, then g = 2 and g = -2 both will give you same phenotype 2.

Back from math and into biology, in many mendelic traits, which are traits where a phenotype depends on a single gene, the receive allele is simply an allele that does not produce a particular product, such as a pigment. Such as blue eyes, which are eyes that lack melanin (the eye colour is not a perfect example, as it turns out it is not exactly mendelian trait, but lets assume for simplicity it is).

Obviously, if a gene is not producing a certain product, a protein that is directly involved in some pathway, it is because it is "damaged" in some way. And there are many way it might be damaged. A protein might be produced, but it is non-functional, shorter, or the protein might not be produced at all. So many different mutations might be responsible for the same trait.

When we look at polygenic traits like height, we will see many different genes that are responsible for a small difference in height. When you plot the population phenotype, you might see a normal distribution. Consequently, assuming the same difference for every gene and 100 genes and an on/off effect of a particular gene, you can get a trait resulting from 50 genes in many way (something like 10^29 combinations).

On top of all this, traits depend on an environment. In the case of height, this is only a potential, you will benefit from your genotype only if you will have plenty of nutrition in your young age to reach this potential.

This difference between genotype and phenotype for polygenic traits, and the effect of an environment, is important when doing a selection in agriculture. Trying to find out how much of the trait is hereditary and how much it is determined by genetics gives you an estimate on how much you can influence the trait by breeding.

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ziptested t1_ja0dw1j wrote

Reply to How old is the ISS REALLY? by gwplayer1

GPS clocks are not reset. They run at adjusted frequency. In general in a satellite mission you want to avoid resets and be prepared to do adjustments not only for time dilation. In a satellite mission I worked we had an onboard clock that was the source of mission time in "milliseconds" since the satellite was powered on soon before the launch. The clock was never adjusted or reset. Time dilation and other errors accumulated. The satellite periodically transmitted a GPS time stamp along with the mission time to the mission control. Based on that the mission control uploaded a schedule of actions in mission time.

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Sibaron t1_ja0db20 wrote

Reply to How do scientists know where the mutation in a gene originated and how long ago the mutation occured? by goose966

What do you mean where it originated? A mutation is stationary in a gene and doesnt move. Should a mutation occur in another location it is a seperate mutation. You cannot really time a mutation, however you can determine the homology between genes and their differences (could be referred to as mutations) and somewhat give an estimate when the genes went from one to become two seperate similar genes. If you are taking somatic mutations like those given rise to cancer, they always appear mostly within a decade at the most before the cancer becomes apparent to the individual.

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epi10000 t1_ja0crjc wrote

Reply to comment by paulHarkonen in how accurate is the greenland ice core oxygen isotope study in regards to earth's climate history ? by Additional-Rhubarb-8

Weeelll... Average lifetime of CO2 molecule in the atmosphere is some centuries or thereabouts, and the troposphere is fairly turbulently mixed on timescales of weeks, i.e. for long lived atmospheric compounds the atmosphere is actually very uniform in remote regions without local sources or strong sinks. Fog banks are just due to local T & RH fluctuations which are extremely transient when compared to most atmospheric gases. So you're partially right, but given that we aim for precision here I just had to jump in :)

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imdoneanymore t1_ja09w58 wrote

Reply to comment by Ieatadapoopoo in When a volcano erupts, does this affect the pressure building up in other volcanoes? by Rhamni

You may want to read this

https://www.usgs.gov/news/volcano-watch-new-research-sheds-light-recent-pahala-earthquake-swarms

on the Pahala quakes that are happening between Mauna Loa and Kilauea. It’s all about plumbing and after ML’s recent eruption there are geologists all over the area now, because what they thought to be true is being challenged by what happened in this last eruption. It’s really interesting stuff. And a rabbit hole lol.

I live on the slopes of ML and find it fascinating.

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