Heat adaptive mechanism

Heatadaptive mechanism

Adaptationentails lastingevolutionary (genetic)alterationthat takeplacein allindividualsin a givenpopulation.Whenan environmental pressureis regularandlastsforseveralgenerations,adaptationmay occurthrough biologicalevolution.Individualswhohavea traitthat providesa benefitin respondingto specificstressesare likelyto livelongerandpasssuchkindsof traitsto thesubsequentgenerationsthrough naturalselection.Examplesof biologicaladaptationsin modernhumansincludephysiological changesthat occurdueto heatthatleadto heavypigmentation of theskinin tropicalregions.Howdomodernhumansrespondto heat?Thediscussionbelowshowshowmodernhumanis adaptedto temperature(Sakwa et al 10).

Humansrespondto heatthrough sweating. Humans,therefore,have1.6 million sweatglandsprovidingabilityto removeup to 3 liters of sweatin one hourduring heavyworkin hightemperature.Vasodilatation can alsohelpthebodyto loseextraheatwhilethevasoconstriction allowsthebodyto retainheatwhenitis cold.Humansrespondphysiologically to coldby heatproductionas wellas heatretention.Shivering,vasoconstriction andincreasedmetabolic ratesactas shorttimeresponsemeasuresto cold.Longtimemeasuresincludethe developmentof prolongedvasoconstriction evenifthere is nodangerof frostbite andalternatingvasodilatation andvasoconstriction whenfrostbite posesa danger.Thisimpacthumanspositivelyin that ithelpthem to regulatebodytemperatureshencetheycan survivein extremetemperatures(Emilie 212).

Biologicaladaptationsin modernhumanshavebeenwitnessedallover theworld.Populationof humanswhohavea beneficialtraitin respondingto specificstressesare likelyto livelongerandpasssuchkindsof traitsto thesubsequentgenerationsthrough naturalselection.Modernhumanpopulationsbiologically respondto hightemperaturesby sweatingthrough sweatglandsandalsorespondto coldby vasodilatation. Naturalselectionhas helpedpeoplein thelowland around the equator toresisthigh temperatures and those in highlands to resist cold temperatures.Theseadaptationsmechanismshaveimpactedhumanspositivelyin thattheyhaveensuredsurvivalof humans’populationsin severeclimatic conditions(Emilie 198).

WorksCited

Emilie,Smyth. HumanEvolution: Neanderthals and Homosapiens.U.S: Wiley, 2010. Print.

Sawka,Michael N, John W. Castellani, Kent B. Pandolf, and Andrew J. Young.HumanAdaptations to Heat and Cold Stress.Ft. Belvoir: Defense Technical Information Center, 2002. Print.