Question

This is a question purely for the purpose of satisfying my own curiosities.

If eukaryotic organisms somehow had 100% accuracy in terms of replicating DNA (i.e. no mutations ever!), how do you think that this would affect genetic diversity? Would the change be significant, minute, beneficial, detrimental, neutral? thanks <3

Answer 1

@brittanyrolfe

Answer 2

I don't think this would have any significant impact, in humans at least. Most of the mutations seen in humans leads to disease, mental disabilities or cancer which of course lead to no positive impact. There are very few mutations that can occur and be beneficial. If an individual had no possible way of having the occurrence of mutations, then I think that would be able to live longer and healthier lives because (and here is the cool part) it is believed that when we grow old, our cells have mutated to look a little different and function a little different. This is why your skin may start to sag or you may start to lose your vision when you become older. It is hypothesized that the more your DNA replicates, the shorter each strand gets... as if pieces of it are being lost over the years. This could explain some of the reasons elderly individuals are must more fragile, and different looking than that of youngsters.

Answer 3

I mean, if an individual were to never encounter mutations, could you say they might be able to live forever?

Answer 4

Most of diversity amongst humans comes from the independent assortment of how alleles for a trait line up at the metaphase plate in meiosis I. At which at this point homologous chromosomes will aline along non-homologous sister chromatids/synapse, and then proceed to undergo crossing over. This is what produces significant variation in humans. In actual DNA replication in the S phase of a cell's cycle, a mutation will either in many cases be spotted by DNA Polyermase I/III or it will go un noticed and it may result in a malfunctioning protein which leads to a premature apoptosis of the cell, or a mutation could lead to a possible gene malfunction which alters the cell's cell cycle control checkpoints which would cause unregulated division and lead to eventual cancer, or there is the rare chance that the mutation is beneficial but this is largely not the case.

Sorry that this is kinda all of the place with respect to somatic and gamete reproduction and variation. Obviously this isnt everything but maybe it provides some insight ? :/

Answer 5

Also its not that humans pass away from gene mutation in 100% of cases. It seems to largely be effected by the depletion of telomeres with each cellular division. Once the genome runs out of telomeres, each DNA replication starts cutting into actual genes which code for important proteins.

Answer 6

Interesting...I'll keep this open for a little while longer to encourage more discussion

Answer 7

@Jamierox4ev3r If you are asking what would happen if we passed on our genes 100% of the time with no mutations, you would still end up with an organism that is different to other organisms, and that's completely dependent on the environment. And how environmental pressures impact an organism.

Answer 8

@Jamierox4ev3r For example, if both organisms have the "depression gene", notice I use quotes around "depression gene" because that's a broad term being used. If both organisms have the same genes, one organism might be in an environment that promoted the depression gene --> leading to that organism to be depressed, while the other organism isn't in the environment to express that gene --> which would lead to suppression. etc.

Answer 9

If you passed on your genes 100% of the time, this would be called ASEXUAL reproduction. There are some cases where the environment plays a role in the phenotype that is displayed in humans or animals. For example, wolves can change their fur color during different times of the year as means of survival. Jamierox4ev3r was asking what would happen is an organism was able to replicate their DNA without any change of mutations occurring during their lifetime. @alphadxg

Answer 10

I agree with most of the discussions while looking at a relatively small window, say, our life time.

If we look from the evolution point of view, mutations will definitely help with survival in the long term by having a larger gene pool. While most of the mutations we see today are linked to diseases, many beneficial ones are not noticed. In reality, mutations gone unnoticed could actually protect us from certain situations. For example, people who have the B*07 and B*14 versions of the human leukocyte antigen-B gene would fight Ebola much better than others, yet these people do not know they have this advantage and how and since when they got those genes. (ref: http://www.livescience.com/47203-ebola-how-people-survive.html)

I would say that mutations are beneficial for man-kind from the evolution point of view.