43
votes
Accepted
How many times has SARS-CoV-2 mutated?
This question makes a number of incorrect assumptions and I don't have time to correct them. The short answer is that the virus has mutated probably hundreds of times since it entered humans in late ...
- 14.2k
37
votes
Accepted
Are mutations a source of genetic variation?
Going through the possible answers
(A) Rates tend to be very high in most populations.
This is a very unclear statement. What does "high" mean? In humans, the average mutation rate per ...
- 68k
22
votes
Accepted
Can the SARS‑CoV‑2 virus mutate in people who have been fully vaccinated?
Since vaccination is not 100% protective against infection (i.e. the virus can sometimes succeed in establishing and replicating in a vaccinated host's body), the answer is yes. Furthermore, since ...
- 5,324
18
votes
Accepted
How do we explain the white feathers of an albino peacock?
The surface structuresa that are responsible for the structural coloration of peacock feathers are actually barbules and rods made of the very same biopolymer that is responsible for pigmentation in ...
- 2,106
13
votes
Accepted
How does Darwinian Evolution work?
I accidentally wrote a lot!
I first discuss the term Darwinian evolution. I then describe the main evolutionary processes insisting on the two elements of interest in your question, that is mutations ...
- 68k
13
votes
Are all carcinogens mutagens?
How can a non-mutagenic agent be carcinogenic?
An agent that causes overexpression of oncogenes or inhibition of tumor suppressors, would be carcinogenic but not mutagenic.
HPV, for instance, produces ...
- 35.2k
13
votes
Accepted
Do mutations occur while growing virus for preparing inactivated viral vaccine?
Very simply, mutations do occur, as they do for any cultured organism. This is a well recognized problem in many fields of biology where organisms are cultured and remains in particular a problem for ...
- 11.2k
12
votes
Why are cancer rates low in large animals?
Short answer
Large animals do get cancer. They may contract cancer with an incidence less than that estimated by absolute cell numbers, but there seems to be a lack of data on cancer rates in large ...
- 52.3k
12
votes
Are all carcinogens mutagens?
Alcohol itself is non-mutagenic because it does not directly alter DNA. (Additionally ethanol enhances carcinogenesis and is itself not a carcinogen - updated) There are similar non-mutagenic ...
- 147
11
votes
Has a beneficial mutation ever been documented?
The answer depends on what you mean by "observed".
Bacteria acquire antibiotic resistance genes all the time, for example. This happens 'in the wild', but you can see in the lab that bacteria can ...
- 1,301
10
votes
Accepted
Are mutations random?
Short answer
The claim is unclear but is essentially misleading and wrong. However, IMO, for lay people, it is a good approximation to just think that mutations are random!
Here, on Understanding ...
- 68k
10
votes
Accepted
Saturated Mutagenesis Screening
This sort of method is indeed quite useful and frequently used in synthetic biology: I've used a similar approach before to generate 5' insulators for promoters.
Calculating the exact theoretical ...
- 6,977
9
votes
Accepted
How close genetically is the most human-like chimpanzee to the most chimp-like human?
You may be interested in this 2005 Nature paper from the Chimpanzee Sequencing and Analysis Consortium: Initial sequence of the chimpanzee genome and comparison with the human genome. It breaks down ...
- 445
8
votes
Accepted
Isn't biological immortality strictly speaking impossible?
Good question.
There are many organisms that are technically biologically immortal. However, I would like to point out that the definition of biological immortality is this:
...cells that are not ...
- 1,836
8
votes
Accepted
Are four-leaf clovers mutations, developmental errors, or something more complicated?
A recessive gene for four leaves has been identified (Tashiro et al., 2010). The clover is a tetraploid species and together with the fact that environmental conditions may also suppress the ...
- 52.3k
8
votes
Is it plausible that strict lockdowns made it more likely for the new variant of COVID to have emerged?
While I get your intuition, the hypothesis seems implausible
Emerge of new CoV variants should be considered proportional to the
current spread of the virus. Each virus has a certain mutation rate ...
- 1,597
8
votes
Amino Acid mutation profile for human coronavirus: Why is the mutation from T to I so frequent?
The change from C to T (or U in the case of RNA) can happen via the oxidation and deamination of the Cytosine (see reference 1 for the explanation of the mechanism).
The mechanisms looks like the ...
- 51.5k
7
votes
Do mutant alleles result from mutation of the wild type?
No, not necessarily!
The terms might be confusing I agree. The most common allele (the wild type allele) might be a mutant of one other type of allele (one mutant allele) present in the population.
...
- 68k
7
votes
Why is mutation rate high in introns?
Not less efficient, but introns are under less selective pressure than exons. Exons actually encode the protein. A single bp insertion will ruin a mRNA encoding a protein by causing a frame shift in ...
- 2,916
7
votes
Accepted
Has a beneficial mutation ever been documented?
Lactase persistence
This is a somewhat unusual example but has been well studied, and would seem to satisfy the criteria of the question. Let me start by quoting the Wikipedia entry for those ...
- 24.3k
7
votes
Accepted
Do organisms have a mechanism to control how fast mutations occur?
The ability of a population to respond to environmental change through evolution occurs over generations, and so the generation time of an organism has to be less than the time scale of the ...
- 17.6k
7
votes
Are STOP codons impacted by base insertion or deletion mutation?
Yes. Mutations can affect STOP codons and they do relatively commonly. These are important because they can lead to significant changes in the resulting peptide and are likely to affect protein ...
- 420
7
votes
Is it plausible that strict lockdowns made it more likely for the new variant of COVID to have emerged?
This is more plausible (second point below) and less plausible (third point below).
Selective advantage The emergence of a new strain of a virus relates to the selective advantage (Gordo 2009). This ...
- 171
7
votes
How exactly do mutations cause genetic variation in bilaterians?
For example, does the mutation need to occur in the DNA of either the specific sperm or the specific egg that gave rise to you?
To give rise to heritable genetic variation in the sense that it's a ...
- 44k
6
votes
Accepted
Do mutant alleles result from mutation of the wild type?
The determination of whether an allele is wild-type or mutant has to do with the frequency that it is observed within a population.
In genetics, a wild-type allele can be defined as
an allele, or ...
- 4,985
6
votes
How close genetically is the most human-like chimpanzee to the most chimp-like human?
The answer given by leekaiinthesky and partially in the comments on the question give a good general picture. I also think that the variation within the respective species is way less than between the ...
- 2,868
6
votes
How to find mutations related to disease for a protein?
I think I understand what you are asking so I will make a little guide to find what you need:
NOTE the mutations you are searching for are probably on gene level so you can search your protein on ...
- 2,380
6
votes
Accepted
Why do mutations not take place in mRNA of higher eukaryotes?
The premise of the questions suggests that mutations cannot take place in the mRNAs of higher eukaryotes.
To answer your question I think it is important to consider two viewpoints:
First, from a ...
- 620
6
votes
Whether de novo mutation can be inherited or not?
De novo mutations can be inherited if they occur in the germline cells, those responsible for making the sperm or the egg. If you have a de novo mutation in a blood cell or a skin cell, this doesn't ...
- 6,192
Only top scored, non community-wiki answers of a minimum length are eligible