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Like for instance, introducing cancer or radiation, to a large group of insects/animals that can reproduce very quickly, would it result in the surviving population of these living things to be more resistant to whatever adverse condition that was subjected upon it?

plu
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  • Or how about conditions that should lead to cancer? I guess having that "pathology" tag wouldn't make sense in this case, I'll remove that. – plu Oct 01 '17 at 00:20
  • From your edit, it seems that you are not interested in transmissible disease anymore (and so my answer would be off) but in cancer specifically. It feels like you may not really know what a cancer is (esp. when we consider what you wrote before the edit). You should definitely read a bit about cancers. Is the question "Is there selection to reduce sensitivity to cancer?", the answer is yes but almost by definition of what a cancer is, so I am unsure what you are really asking. – Remi.b Oct 01 '17 at 00:26
  • Thanks @Remi.b, Reading some general info about cancer, https://www.medicalnewstoday.com/info/cancer-oncology, I'm not sure how that could by definition imply "selection to reduce sensitivity to cancer". I really have zero background in any biology-related field, but this question had been an ongoing curiosity for some time. – plu Oct 01 '17 at 00:43
  • @Remi.b As for what I'm really asking, I just wanted to know if it were possible to over natural selection, gradually evolve some group of living things to be more resistant to any harsh condition, such as extreme heat/cold, intense radiation, any disease, etc. This curiosity might have been inspired by new stories related to "tardigrades" (https://gizmodo.com/genes-hold-the-key-to-the-water-bears-indestructibility-1786814698), that are highly resistant to extreme conditions. – plu Oct 01 '17 at 00:55
  • I'm not sure what you mean by to over natural selection? – Remi.b Oct 01 '17 at 01:03
  • @Remi.b By "natural selection", I meant, for instance, introduce an extreme condition to a group of ants (i.e.: low temperature that kills most but not all), then after several generations, the surviving ants should be more able to tolerate low temperatures. So if other things were applied the same way (introducing a disease that causes most but not all things to die), we should get similar results? I assume this is what you meant in your response by "selection against". – plu Oct 01 '17 at 01:13
  • Yes, your description of the consequences of natural selection is correct. It is more the use of the verb over that I did not understand in the context of your sentence. Did you mean 'to put an end to selection' or something? – Remi.b Oct 01 '17 at 01:18
  • Selection against a trait is the same as selection for the opposite trait. For example, for mice living on white sand, there is selection for being white and against being black for increased camouflage (and the opposite is true on darker substrate; Nachman et al. 2002). – Remi.b Oct 01 '17 at 01:21
  • @Remi.b, I'm not able to edit the comment, but it should be rephrased as: "I just wanted to know if it were possible to, by the means of natural selection, gradually evolve some group of living things....", sorry for any confusion. – plu Oct 01 '17 at 01:23
  • Oh I get what you meant now! No worries. Btw, I made a tiny edit at my answer you might want to have a look at. – Remi.b Oct 01 '17 at 01:28
  • Resistance is usually present in a population already and the selective pressure makes it apparent. So organisms don't develop resistance. They have resistance that is selected for. Even in bacteria that can survive ever more antibiotics at higher doses, they do not survive until a mutant arises that when exposed to the environment, survives. – AMR Oct 01 '17 at 03:05

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I don't think this answer answers the post given the discussion and new edits. I will leave it here nevertheless just in case I still misunderstand the OP's question.

[..] introducing cancer or radiation [..]

A cancer is not a transmissible disease (except very few cancer last the facial tumor in Tasmianian devils). A radiation is not even a pathology, it is a physical phenomenon which include light. Did you rather mean something like a virulent flu for example?

If we introduce any disease or deadly effect to a large group of living things, will such a group be able to develop a resistance?

The population may or may not survive. It depends upon many parameters such as how virulent is the parasite, how large is the population, whether individuals in the population have already encountered the parasite before, whether there is already genetic variants resistant in the population or whether de novo mutations will be needed, etc... There is no way to answer to this question in the general sense.

Note by the way, that an individual may be resistant or tolerant to a certain disease.

Most of the time, the population survive well. The population will likely decrease in size a little bit though.

Remi.b
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Is there selection against cancer?

What is selection?

Let's start by explaining what selection is. Selection is a differential in fitness among different genotypes. In other words, if you consider a phenotypic trait for which there is some variance in the population. If, in the population, there is a correlation between this trait and fitness and there is a correlation between this trait and genetics, then there is selection.

The three ingredients for selection are

  • Variance for the phenotypic trait
  • Correlation between the phenotypic trait and fitness
  • Correlation between the phenotypic trait and genetics

These three bullet points are known as Lewontin's recipe. The last bullet point could be rephrased into "the phenotypic trait is heritable" and all bullet points put together could be rephrased into "fitness is heritable". Have a look at the post Why is a heritability coefficient not an index of how “genetic” something is? to understand the concept of heritability.

Is there selection on cancer?

Cancer is fundamentally a genetic disease. If this is unclear to you, you might want to read a bit more about cancer.

There is variance in the population in cancer (not everybody has a cancer but some people do) so we satisfied our first bullet point. Cancer is a genetic trait. So we satisfied our second bullet point. Cancer is a disease and therefore affect fitness (cancers kill) so we satisfied our third bullet point. In short, yes there is selection on cancer.

How does increasing the amount of carcinogens in our environment will affect selection on cancer?

From wiki

A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis, the formation of cancer.

If you increase the amount of carcinogens in our environment, you are going to increase the prevalence of the disease, which will increase the variance for the disease (unless the prevalence would become very very very high) and therefore increase selection against cancer.

Does selection work?

I just wanted to know if it were possible [, by the means of] natural selection [to] gradually evolve some group of living things to be more resistant to any harsh condition, such as extreme heat/cold, intense radiation, any disease, etc.

Yes, it is possible. Natural selection does work.

Note that if you are interested in a short intro course to evolutionary biology, then you may enjoy having a look at Evo101 by UC Berkeley.

Remi.b
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  • Thanks for edit to more closely follow updates in the the comments. I'll have a look into that Evo101 link sometime. – plu Oct 01 '17 at 02:11