Articles term test 2

Lactose

disaccharide sugar in milk, hydrolysed and separated into monosaccharides (glc and gal), enzyme lactase digest, undigest fermenten by colonic bacteria

Lactase persistance

ability in human to digest lactose past weaning (not normal in mammals), 4 genetic mutation in LTC gene on chromosome 2, in 35% of adults - higher in pastoralist cultures, dominat trait

Demic diffusion model

neolithic culture/lifestyle(agriculture) spread through migration, no admixturation

Cultural diffusion model

mesolithic learn skills from neighbouring neolithic

recent intermediate model of neolithic transition

migration and admixturing

Milk consumption

part of neolithic revolution - animal domestication, nourishment for adults, started fermented product (cheese) bc less lactose

Secondary product revolution model

animal domesticate for “primary product” (meat, bone, leather), later learn what collected well alive (wool, milk)

reverse cause argument

lactase persistence freq grown in many small groups, genetic drift, milk drinking adopted after

gene culture coevolution/ cultral historical hypothesis

lactase persistence positively selected in dairying population, ancient DNA supports (absent before dairying)

calcium assimilation hypothesis/ cultural mediation hypothesis

sunlight exposure aid vit D production - needed calcium absorption, milk contains small vit D and large calcium amount, milk drinking helped avoid vit D deficiency diesease (rickets), lactose acts like vit D

Adaptation to arid enviroment

milk uncontaminated source of fluid, lactose intolerance symptoms cause dehydration

Pacific polynesian population lactose presistence

higher than close similar groups, from gene flow - common european ancestor

intermediate frequency of lactose malabsorption

between 30-60%, depend on degree of gene flow, mixed ethnic groups

Tokelau lactose absorption

higher than expectd, gene flow accounts for most (european or shared common), exarbated by bottleneck (migration of foreigne to make up)

Tokelau bottleneck

peruvian slaver took nearly half the population and all the able bodied men, cause high lactose absorption(increase european migrant genes) and HLA-Bw40 gene

Phenylketonuria (PKU)

recessive lethal mutation, abnormal AA metabolism (Phe  to Tyr), lightened pigmentation and nervous system impairments, high in Celtic heritage, heterozygote advantage maintain in population

PKU pigmentation hypothesis

Homozygous - decreasing availability of tyrosine (can’t break down to) cause less melanin and lighten pigmentation, heterozygote - partial reduction in tyrosine availabbility, potential adapation to increase sun exposure (vit D production) in winter

Tay-sachs diesease

recessive lethal mutation in HEXA gene (chromosome 15), lead accumulation gangliosides causing neurological symptoms, (5x) high frequency in Ashkenazi jews, maintained by heterozygote advantage, lysosomal storage disease

Ashkenazi jews

high freq of 3 lysosomal storage diseases (tay-sach, Neimann-Pick, Gauchers), crowed urban squalor causes 2 major TB epidemics (selective pressure)

Cystic fibrosis

lethal (life expectancy 24y) recessive mutation (missing Phe  from 3bp deletion) in CFTR gene on chromosme 7, loss of ATP binding site (regulator), higher in european descent, maintained by heterozygote advantage, spread by migration neolithic farmers

Symptoms of CF

decrease ion conducatnce increasing mucus viscosity, obstruction cause hypoxia/hypercapnia/acidosis, mucus as medium for bacterial growth (lung tissue destruction), Block pancreatic enzyme from duodenum (lack nutrient absorption), reduce feritlity (male sterile), dehydration by lack of Na+/Cl- reabsorption

Fertility hypothesis of CF

males carriers have advance fertility (more offspring) - research doesn’t prove (ascertainment bias- bigger family more liekly to express)

TB hypothesis of CF

heterozygote resistance to TB, increase MPS production from TB exposure breaks by fluid accumulation, MPS breaks up and free fluid spaces appear, lacks susbtance

Cholera hypothesis of CF

entertoxin of E.coli (similar to Cholera) cause diarrhea and vomiting leading to dehydration, endemic, CF fails to secrete chloride therefore loss less fluid, saw same thing with Cholera entertoxin in small intestine

Malaria genetic adaptation

Sickle cell amenia, Thalassemia, G6P deficiency

coevolution

gene cultrual interaction leading to adpations

adaptation

increase organsim chance for survival and reproduction

social distrubtion of malaira (4)

more children have, more men have, more agropastoral workers have, more peasent then shepards have

P. vivax

endemic nature in Sardinia, consistenly high incidence all year

P. falciparum

more deadly, summmer epidemic, unstable/seasonal incidence

Anopheles labranchia

malaria vector, seasonal fluctuation in population density, nondomestic nature(don’t reise human habitation), prefernce fresh water for breeding, distrubition in all ecological zone of Sardinina, hight pop around nucleated settlements

Thalassemia and G6P deficieny

genetic adaption to malaria (protection agaisnt death) correlation among malair and high gene freq distrubitions, gene freq >30% in Sardinia

Thalassemia

genetic disease, abnormal gen at 2 Hb loci causing to be defective, homzygous - major (severe anemia and death) and heterozygote minor (chronic anemia for some), cannot support development of plasmodium parasite, expensive adaptation (fitness low)

G6P deficiency

enzyme in RBC, must converts Glu to Fru through slower pathways, sex linked trait (more males affected), cause Favism (hemolytic crisis from eating Fava bean), inhibits plasmodium parasite reproduction, reduce RBC glutathion (GSH), fitness would be higher if not for Fava bean consumption

RBC glutathion (GSH)

protect cell from excessive oxidation, low level trigger hemolysis of RBC, what happen in Favism crisis

Sardinia cultrual adaption to malaira

inverse transhumance - shepards avoid high risk zones, nucleated settlement pattern - decrease anophele densities 

Inverse transhumance

land utilization pattern, seasonal movemnt of flocks between elevations with pasture/water availbility (down for winter), create theft risk (1 shepherd to protect), secondary product collection down in isolated pastures