Hot answers tagged mutations
13
My friend Brightblades is right in one thing. It seems your teacher was working off a caricature of what the theory of evolution actually says. First of all, you should read Sklivvz's excellent answer at this question. Now to address the elephant in the room, the accident at Chernobyl only happened in 1986. That was only 26 years ago. In that timeframe, ...
7
That would be hard to say because really beneficial mutations become well distributed through the genome. Basically the differences between us and chimpanzees are a catalog of all the beneficial (or completely neutral) mutations since the ~4.7 M years since we diverged from each other.
Separating them from changes which have no special effect would be ...
6
Just continue scrolling down wikipedia: there are also listed two examples of beneficial mutations: the one conferring HIV resistance, and the one conferring malaria resistance.
Note that 'beneficial' is relative. The mutation associated to malaria resistance is actually causing sickle cell disease.
4
I can't answer your third, but I can answer your first two. With one word, in fact:
Bioluminescence
http://brightnepenthe.blogspot.com/2010/08/palate-cleanser-90.html
That's the deep ocean at night for ya. Unlike underground environments and caves, it's not pitch black pretty much anywhere in the ocean. There are things to see everywhere, and they play ...
4
Others have posted that the term beneficial in genetics is contextual - single mutations may be harmless, unless another mutation is co-inherited; this is called epistasis (where more than a single mutation/genotype/allele is required for the phenotype).
I have not studied the list comprehensively, but there is a 'catalog' of all robust genome-wide ...
3
The processes are called gene rearrangement and somatic hypermutation, and are used by maturing B-cells to generate very (very) large amounts of diversity in the antibody repertoire. If your institution has access, this great article in Annual Reviews in Immunology has all the details, or you can read about it in Janeway (slightly outdated edition). ...
3
You seem to be assuming that mutation rates are somehow constant over evolutionary time. They are not. Mutation rates will change according to the stresses a species is subjected to. If you take a bacterial population and place it in a stressful environment (high/low temperatures, oxidative stress, lack of nourishment or whatever) you are likely to see an ...
2
The anthropologist Svante Pääbo is more recently famous for trying to track down the 'language gene'. There isn't a lot of reference to Chomsky in his work as I've noticed, but it is to me the same intriguing idea.
That being that the chimpanzee and the bonobo have 99+% identical to human genome sequences and we also have data from human variations as ...
2
From my reading on M. tuberculosis, I know that this organism has a pretty high mutation rate
Huh, that's news to me. In fact, Mtb has a rather low mutation rate and rather low genetic variance. See the paper by Sherman & Gagneux in Nature genetics. The paper does state that mutation rate in latent infection is higher than expected or previously ...
2
Recently, samples from different parts of cottonwood trees have been sequenced (Nature News). The conclusion:
“The variation within a tree is as great as the variation across unrelated trees,” says Ken Paige, an evolutionary biologist at the University of Illinois at Urbana-Champaign, who led the team that made the discovery.
This doesn't say anything ...
2
(A)
Will probably not. You inherit blood type, but not actual erythrocytes (though the mother's erythrocytes do interact with a fetus).
(B)
Will probably not. However, while in the uterus and for the first few weeks outside the uterus the Mother's immune system is effectively the newborn's immune system. While the mother doesn't pass on any myeloid ...
2
No. Surprisingly, there is an adaptive immune system in prokaryotes. This is still widely unknown. The newest review is
S. Al-Attar, E. R. Westra et al: Clustered regularly interspaced short palindromic repeats (CRISPRs): the hallmark of an ingenious antiviral defense mechanism in prokaryotes. In: Biological chemistry. 392, 4, April 2011, 277–289. ...
1
Antibody molecules or immunoglobulins (Ig) consist of heavy and light chains (e.g. two of each in IgG). Both heavy and light chains have variable domains at their N termini.
During development of the immune system the pro-B cells in the bone marrow undergo gene segment rearrangements, bringing V and J segments together for Ig light chain production, and V,D ...
1
First, the recombination equation is:
cM = recombinants/(recombinants AND parentals) * 100
Let's assign the following genotypes for clarity's sake:
RR = black bristles
Rr = black bristles
rr = red bristles
SS = pebbly eyes
Ss = pebbly eyes
ss = shiny eyes
F1 cross: rrSS x RRss = RrSs (all progeny)
F2 cross: RrSs (F1) x rrss = ?
You would have the ...
1
Not sure if the exome sequencing is the way to go for this kind of tasks, especially if you have an idea of the mutations you might be looking for. Current arrays are pretty performant and are much more rapid and cheap.
For the data, you might consider having a look on The Cancer Genome Atlas. Otherwise Biological Networks might provide you the API for you ...
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