Evolution and Human Health

exam 3

The ghost of famines past

• worked as powerful agents of natural selection

ex: prima people

Diabetes

• A group of metabolic disorders related to high blood sugar levels

• Cardiovascular disease, stroke, chronic kidney disease, foot ulcers, and damage to the eyes

• not a disease, its a collection of symptoms

• eat somehting with carbohydrates = increase the level of sugar (Mainly Glucose) on the blood

• use of insulin = Blood sugar level go down

• can turn stored fat into glucose 

Type 1

• caused by the destruction of insulin-producing cells resulting in the body producing little or no insulin

Type 2

• caused by insulin resistance and relative deficiency where insulin produced by the body is not used effectively 

But what does diabetes has to do with famines?

• famines have worked as powerful agents of natural selection

• Selection the genes that are the most efficient at using food

• during a famine, those who are diabetic tend to surive, then they reproduce and the whole pop. is diabetic, which leads to a genetic bottleneck 

  • A Genetic or Population bottleneck is an event that drastically reduces the size of a population and therefore, decreases its gene pool. Due to the event, the remaining population becomes more genetically homogenous

• Carbs used to be rare, so these mutations helped people to use them efficiently and store them as “fat” very fast

Prima people (arizona)

• are all overweight (3/4 are obese) and have the highest rate of diabetes in the world

• the cycles of drought and famine in the desert made the Pima’s to undergo multiple genetic bottlenecks that spread the HLA-DQA1, HLA-DQB1, and HLA-DRB1genes across the population

• This genetic bottleneck allowed scientists to identify spree of the genes associated with diabetes (Type 1) HLA genes

• The Pima evolved in the desert and their genes help them survive

• Now, those same genes are their #1 cause of mortality

what determines which culture will dominate another

• the "discovery" of America - 1400s

• pre-colombus North America was full differnt cultures

  • Maya

  • Aztec

  • Inca

• Pre-coumbus America had 2 empires

How fewer than 5000 people from Europe dominated more than 150 000 000
people in the Americas?

• guns and diseases (mainly) - set of new pathogens

• stimated that 120 000 000 died in the first 75 years after the arrival of Europeans

• city livestock

• large disease outbreaks:

  • no clean water

  • no sewer

  • no soap 

  • no house toilets

• pathogens moving across species

John Snow

• wanted to discover what these people were dying from

  • People lived far from the brewery = died

  • people lived next to the brewery = lived

• For 100’s of years, people from Europe lived in these conditions

• Father of Epidemiology and Urban Sanitation

• their immune system evolved

• Over time, epidemics after epidemic, Europeans became immune or resistant to many deadly pathogens

ex: influenza (flu), smallpox, measles, cholera

Pathogens

• a problem for humans for centuries

Historical World population

• first infection point was John Snow

• then antibiotics

New weapons of warfare

• antibiotics were created for soldiers b/c they were dying from infections in the trenches during WW2

• pills - chemical weapons that selectively kill pathogens

• shots - advanced training program for the immune system

evolutionary arms race - medicine

• Pathogens evolve and adapt to Antibiotics and Vaccines

• We are running out of effective antibiotics

• Developing new drugs is expensive

They Hygiene Hypothesis

• a theory that suggests an increase in allergies and autoimmune diseases may be linked to a reduced exposure to microorganisms, pathogens, and parasites in early childhood due to improved sanitation and hygiene