User talk:Jeffmartin9/sandbox

Evolution Basis of Altitude Sickness
Tibetan and Andean

Tibetans and Andeans have both independently adapted to high altitude independently. The physiological mechanism which they are adapted to high altitude is different and is an example of convergent evolution. The genetic basis of these adaptation is not known. Although their is probably a genetic basis to high altitude adaption there is also environmental factors at play. 123godawgs (talk) 07:05, 1 March 2016 (UTC)

Applications of Understanding Evolution of Altitude Sickness in Pregnancy
Very interesting paper that describes the application of altitude sickness for morning sickness in pregnant women. By understanding the natural variants of hypoxia-inducible factor (HIF) and endothelin-1 (ET-1), in population which have adapted to altitude sickness we could potential understand the mechanism of morning sickness. .123godawgs (talk) 07:05, 1 March 2016 (UTC)

Basic Biology (Focus on Secondary Sources)
Date: 2/29/16

PDFs:

1. http://mbe.oxfordjournals.org/content/29/11/3359.full.pdf

2. http://ac.els-cdn.com/S0959437X14000641/1-s2.0-S0959437X14000641-main.pdf?_tid=9e02f89c-df2b-11e5-8810-00000aacb362&acdnat=1456781593_66c9c18ef958d0de077f11f3fe345b32

3. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-185X.2012.00227.x/epdf (p 844-5)

Notes:

1. Genetic Adaptation of the Hypoxia-Inducible Factor Pathway to Oxygen Pressure among Eurasian Human Populations


 * The EGLN1 gene, from the hypoxia-inducible factor (HIF) pathway, was identified as being involved in the hypoxic adaptation of highland Andeans and Tibetans.


 * The identification of the EGLN1 gene from the HIF pathway suggests a common adaptive mechanism for Eurasian human populations residing at different altitudes with different oxygen pressures


 * Different ways your body restores arterial oxygen content:

1. cardiovascular responses which increase cardiac output

2. alveolar gases exchange, kidney, and CNS responses to change the oxygen and carbon dioxide partial pressures

3. increased hemoglobin concentration

2. Adaptations to local environments in modern human populations [REVIEW]


 * High-altitude environments are challenging for long term human habitation due to various environmental stressors, such as low barometric O2 pressure, low temperature and high UV radiation


 * In Tibetans, multiple studies have found that two genes, EGLN1 (egl nine homolog 1) and EPAS1 (endothelial PAS-domain containing protein 1) have unusually high numbers of SNPs in comparison to low-altitude East Asians


 * All three high-altitude populations had a significant enrichment of selection signals around genes involved in the response to hypoxia

3. Genetic explorations of recent human metabolic adaptations: hypotheses and evidence [REVIEW, P. 844-5]


 * Tibetans living at 3,500 to 4,500 meters above sea level increase oxygen availability to cells in spite of low pulmonary oxygen content by increasing resting ventilation rate, vasodilation, and blood flow


 * Andeans living above 2,500 meters do not show the same physiological adaptations to high altitude: they retain the high haemoglobin levels of lowland people living at high altitudes, and as a result have elevated risk of mountain sickness with age, and low birth weight


 * The specific genes within the HIF pathway under selection differ between these populations.


 * Tibetans experienced positive selection on variants in EPAS1, which has been found to regulate expression of the EPO gene, which is responsible for hemoglobin production


 * One mutation in EPAS1 is known to cause excessive hemoglobin production

more bio
altitude sickness- spectrum of disorders that occur at high altitudes adaptation to altitude- there is a genetic basis to adaptive phenotype. important genes and proteins include:
 * three major clinical syndromes: acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema (HACE); these are on a continuum of severity, all caused by decrease in oxygen
 * occurs because partial pressure of oxygen in atmosphere is too low at high altitudes
 * driver of oxygen delivery to mitochondria is the pressure difference
 * what counts as “high altitude” varies from person to person for unknown reasons; scientists use ~2,500m as a working definition
 * hypoxia and hypoxemia cause hyperventilation (acclimatization)
 * EGLN1 encodes oxygen sensor PHD2
 * EPAS1 encodes transcription factor subunit HIF-2α
 * hypoxia inducible factors are a family of transcription factors that regulate response to oxygen levels
 * continuously made and degraded depending on PHD levels
 * Allele frequencies for EGLN1 and EPAS1 provide the strongest evidence for natural selection and association with adaptive phenotypes
 * dampened hemoglobin phenotype beneficial because maintaining high hemoglobin levels is:
 * costly in terms of fitness
 * shown to have side effects such as higher risk of complications during pregnancy or Chronic Mountain Sickness

primary sources: secondary source:
 * Beall, Cynthia M. “Adaptations to High Altitude: Phenotypes and Genotypes”. Annual Review of Anthropology 43 (2014): 251-272. Web.
 * Beall, Cynthia M. “Adaptations to Altitude: A Current Assessment”. Annual Review of Anthropology 30 (2001): 423–456. Web.
 * Gupta, Kapil. "Altitude Sickness." The Gale Encyclopedia of Medicine. Ed. Deirdre S. Blanchfield and Jacqueline L. Longe. 2nd ed. Vol. 1. Detroit: Gale, 2002. 132-134. Gale Virtual Reference Library. Web. 29 Feb. 2016. — Preceding unsigned comment added by Wtdigoh (talk • contribs) 20:24, 1 March 2016 (UTC)

HugzApenguin (talk) 07:09, 1 March 2016 (UTC)

Evo. in Other Species
Topic: evo. in other species. Background sources: http://dx.plos.org/10.1371/journal.pgen.1004466, http://gbe.oxfordjournals.org/content/early/2016/02/22/gbe.evw032 What’s on wikipedia: https://en.wikipedia.org/wiki/High-altitude_adaptation#In_other_mammals In depth discussion of two mammals and two birds. I chose two animals that were not already discussed. Jeffmartin9 (talk) 04:00, 2 March 2016 (UTC)