As there are experiments studying influence of cosmic rays on organisms,
http://www.ncbi.nlm.nih.gov/pubmed/11541768
I ask my self, if there any influence to DNA from atmospheric muons on the Earth surface as well?
The flux is well known,
http://arxiv.org/abs/hep-ph/9803488
but, what is the energy needed to change the DNA? Do cosmics actually have higher probability to change DNA despite of cellular reparation mechanisms? If one takes greater timescales into account, could muons have been one of the causes of biological evolution?
Edit:
Broader context is to approximate, if fluctuations of high energy primary cosmic rays (considering galactic flux, not the sun activity) are correlated to biological evolution. Apart from muons, other direct feedback from cosmic rays to living organisms is the $C-14$ production and incorporation.
Specific question is to approximate, how little is the volume in a cell (whether it is DNA it self or RNA mechanisms modifying DNA), how often does it effectively hit by a secondary cosmic, how high is the probability to hit the cell, when it's most susceptible for mutation.
I think, rate of successful genetic mutation can be calculated as $f_c= (\tau_1 + \tau_2)\cdot f_1 \cdot f_2 $, where $f_1$ and $\tau_1$ would be the cosmics rate and duration of passage, and $f_2$ and $\tau_2$ the sensitivity "rate" or probability and time window for a DNA change
Best Answer
Of course.
Essentially any ionizing radiation can diddle DNA. Altering the DNA in most bodily cells may kill that cell or cause it to misbehave in various ways (including cancer). Or it may do nothing at all (for instance, if it lands on a unused portion of the strand, or turns off one of several copies of a particular genetic switch).
Any ionizing radiation that reaches the reproductive cells can cause mutations in offspring.
That isn't "evolutionary pressure" (which arises from differential reproductive success) but it is the "random variation" part of the process of evolution. That is to say, it is one of the engines of eveolution, but plays no part in the steering.
If you live in an industrialized nation and get the usual complement of medical and dental screens then the cosmic ray background makes up roughly (very roughly) half or your on-going ionizing radiation dose, so you would expect cosmic rays to be responsible for roughly half of the radiation induced mutations (there are other mechanisms so this does not add up to half of all mutations). The next biggest contributor is naturally occurring radio-isotopes ( Potassium-40 and various Uranium and Thorium daughters).
Go to the question of "more or less probable" to do damange is a little trickier, but to first order muons are less likely to change things than other ionizing radiation because they deposit less energy per unit areal-mass-density of track length (the usual unit of energy loss is $\frac{\mathrm{MeV}}{\frac{\mathrm{g}}{\mathrm{cm}^2}}$ where the denominator should be thought or as (mass density) * (track length) or $(\frac{\mathrm{g}}{\mathrm{cm}^3} \mathrm{cm})$ (yeah, particle physicists have stuck with cgs for this because for minimum ionizing particles the answer is 2 in these units)).