User:Vapememes2020/sandbox

This is my sandbox page, which I will primarily be using to experiment with the various editing mechanics provided by Wikipedia.

Physiology

Thermoregulation Edits
Antifreeze proteins: characteristics, occurrence and human exposure". (2002).  Food and Chemical Toxicology  .  40  (7): 899–903.

-For this article I discarded much of the info on the consumption of antifreeze proteins, as this wasn't needed for the thermoregulation article. However much of the information in the article was useful for my citation, for example the article mentioned multiple times that organisms such as fish, insects, plants, and even some fungi and bacteria used these antifreeze proteins. It also mentioned that said antifreeze proteins (AFPs) helped to lower the freezing point of the blood in fish so that said freezing point was lower than that of the seawater surrounding them (and it did so without significantly increasing the osmotic pressure of the plasma). It also mentioned that AFPs were often found in fish living in areas susceptible to ice formation. AFPs according to the article also alter the way ice crystals form and develop, resulting in ice crystals that are smaller or differently shaped than normal. Along with this the amino acid (AA) sequence of AFPs varied a ton between and sometimes even within a species. Molecular weight also varied (with some smaller AFPs being 2.5 kD while larger ones were about 36 kD). The freezing point depression activity of AFPs was also done through non-colligative mechanisms which minimized the effect on osmotic pressure on fish plasma.

I mainly wished to use this article because the "Ectothermic Heating" section of the thermoregulation article, it mentioned that some fish try to cope with low temperatures (particularly those who live in water temperatures below freezing) using antifreeze proteins to resist the formation of ice crystals in their body, however there wasn't any citation to back up this statement. Even though I think this is somewhat common knowledge today the article I read indicated that even as recently as 1969 this wasn't well known, or known at all for that matter so I thought it may have been necessary to include a citation here. I also may use this citation by adding a short little blurb in the "In Plants" section just briefly mentioning that several types of angiosperms possess antifreeze proteins which help lower the freezing point of their tissues.

'''Being Cool: How body temperature influences ageing and longevity. ''Biogerontology. (2015) 16(4):383-97'

In this article I found that I was indeed somewhat wrong, as there was a trend for lower body temperatures to be associated w/ longer lifespans across a wide variety of organisms in both wild and laboratory conditions. Not only this in some cases caloric restriction decreased core body temperatures and increased lifespans. The article also discussed how earlier theories postulated that this relationship was because of entropy, where increased temperatures increased molecular disorder and damage. However the mechanism behind these trends is likely more complex than initially thought as it may relate to endocrine processes mediating more complex physiological responses to temperature changes.

In Drosophila, Daphnia magna and C. elegans, lifespan correlated negatively with temperature, and similar trends were seen in fish too. Various species of Cynolebia and Nothobranchius had increases in lifespan at lower temperatures too. Lab studies have also shown that insects (such as Trichogramma platneri) experience this similar trend, where drops in temperature increase their median lifespan. In fact there didn't seem to be a single case where invertebrate species longevity increased with temperature (with the exception of pathological effects at very low temperatures). Lower temperatures in invertebrates/ectotherms/poikilotherms in general is associated with an overall slower life history and slower rate of development, which may explain the longer lifespans. Some arctic sponges can live for 1550 or 15000 years and this may be because of slower growth rates in their low temperature environment. In ectotherms lower temperatures likely promote longevity because it slows down the reaction rate of various metabolic processes that affect development and life history.

Ectothermic vertebrates (such as several fish species) tend to live longer at lower temperatures. Similar results have been seen in several amphibians (including anurans and the eastern long toed salamander).

Ames dwarf mice also tend to live longer than wild types and had lower temperatures than wild types too.

Transgenic mice also had evidence showing that lower core body temperatures can increase the lifespan (THIS IS THE EXPERIMENT THE WIKIPEDIA ARTICLE TALKED ABOUT).

In a study done in men it was found that lower temperature/insulin and higher DHEAS levels correlated with higher survival rates.

HIbernation/torpor decrease body temperature significantly (sometimes even resulting in the organism turning to ectothermy) and the survival rate of hibernating animals compared to other animals of similar sizes was significantly higher.

Temperature affects longevity in invertebrates, fish, amphibians, mammals and many more organisms, and this affect is seen within and possibly across species. The mechanism behaind this likely is an interplay of neuroendocrine mechanisms in response to low temperature, which in turn affects longevity.

Note, these decreases in temperature were within the range of normal body temperatures, not going to more extreme hypothermia levels of thermal stress.

There's several reasons I wanted to use this article. The main reason I initially wanted to is because I thought it would provide some good counterevidence against the claim that temperature and lifespans are negatively correlated. However aside from the one example involving human females compared to males the article seemed to validate the Wikipedia article's claims throughout the paper. However, this article can still be very useful because it reference the same study the Wikipedia article referenced, but the Wikipedia article used the primary source as a citation for this claim, so this could provide a credible secondary source to support that claim. Along with this I may be able to add a bit more to the longevity and temperature section by mentioning that various organisms show very similar trends aside from just mice (and then using this article as a citation).