Human Evolution and Adaptation to High-altitude - Cynthia Beall

NABT 2009. During the past 100,000 200,000 years, humans have moved out of Africa to an enormous range of environments including the world's high plateaus in the Andes, Tibet, and East Africa. The environmental stress at high altitude is clear: lower barometric pressure results in fewer than normal oxygen molecules in every breath, and therefore in circulation. Lowlanders traveling to high altitudes respond to acute hypoxia - or oxygen deficiency - with homeostatic responses of the lung, heart, blood vessels, and blood. However, native residents of the worlds three high plateaus deliver oxygen more effectively, which is hypothesized to be the result of evolution by natural selection over thousands of years of high-altitude residence. Furthermore, the physiology in these populations differs, which suggests that three replications of the same natural experiment of moving from low to high altitude had different outcomes. There is also evidence of ongoing natural selection differential survival of genotypes in the Tibetan population. Strikingly, the degree of physiological hypoxia of healthy high-altitude natives on these plateaus is in the range considered pathological at low altitudes where it is routinely treated with oxygen therapy. Study of adaptations in healthy hypoxic people may suggest new therapies and interventions for patients with hypoxia at all altitudes.

Category:

Science & Technology

Tags:

• NESCent
• Evolution
• NABT

[Acecool444]

APE - PARENTLY - Evolution is still...well...EVOLVING!

watch?v=sssKuWhc-NY&feature=up­loademail

[BioGuelph]

@Acecool444 changes seen in the Tibetan population found that the genes EPAS1 and EGLN1 were up-regulated which may be due to sequence variations within these haplotypes found within this population. EGLN1 has been shown to play a role in oxygen homeostasis by assisting the formation of the HIF complex, while EPAS1 is a transcription factor involved in oxygen handling as cellular concentrations of O2 fall.

[BioGuelph]

Actually your quite mistaken, biological adaptations are defined as directional selection events that occur in response to changes in selective pressures such as the environment. You’re mistaking biological adaptation with phenotypical plasticity.

Also evolution is not defined as a speciation event, but as the changes in allele frequencies over generations; which can lead to a speciation event.

[Acecool444]

"Biological Adaptation" Not To Be Confused with "Evolution" which is a change of one species becoming another, or Observed Instances of Speciation which is based on hypothesis of which there is no photo evidence of this.

Humans, plants, animals and insects are known to "ADAPT". i.e. lung capacity enlargement due to holding your breath for long periods of time under water, noted in divers, swimmers, surfers. In Insects or Viruses, immune to pesticides/Anti-biotics.

Don't Be Fooled!

[2BarKawi]

@darkfur35 Sorry, love, didn't know you were a woman.... But still, check Tibetan's evolution living at high altitude, you can't deny evoution is still in motion after checking up on that, and again, sorry for the language. And I;m sure you believe in evolution or you wouldn't uise silly excuse like: "Anyone calling people names, shows a lack of intelligents." When in-fact, it's spelt intelligenCE.

[darkfur35]

@2BarKawi You just proved evolution is false. Anyone calling people names, shows a lack of intelligents. Please get educated. My parents?  You are deluded arnt you. You are very weird.

[2BarKawi]

@darkfur35 You are believing what your parents tell you, well done you, give yourself a pat on the back you deluded cunt!

[darkfur35]

You are not unbiased. Plus calling people names proves evolution is a farce. If evolution was true you wouldnt have to call someone stupid to prove your point.

Therefore; Evolution is a bad fairy tale.

[metalbucket2]

@darkfur35 I know lots about science thanks. Real scientists are indeed unbiased and will consider the evidence of barely-literate pre-scientific people of the Middle East that consider a burning bush to be a source of wonder along with the mass of hard evidence from genetics, geology, anatomy to name but 3 disciplines that confirm evolution and conclude that the hard data wins. Peace. Consider God's wonderful plan when you have your wisdom teeth removed.

[pyloric66]

Baby Jesus will not save you from your idiotic comments