Lecture 2: History of Disease

Question 1

What did humans do before farming?

Answer 1

4.5 million years human ancestors(hominids)
were hunter and gatherers

Question 2

Why was disease not present in hunter gatherers?

Answer 2

• small group 50-100 individuals

-disease was not present b/c pathogens were unable too thrive

• groups were never in an area long enough to pollute water sources with human and other waste
• no refuse pile to attract disease carrying insects
• they had no domesticated animals as they were a mobile societies

Question 3

What were the principal sources of disease in hunter gatherers?

Answer 3

They were less exposed than modern man

• Two principle sources of disease:
  ◦ Wild animals
  ◦ Present in Pre Hominid ancestors (but did not rly cause disease) and continue to evolve with us today

Question 4

List the diseases associated with wild animals

Answer 4

‣ Trichinosis (sleeping sickness)
‣ Tularaemia(rabbit fever)
‣ These infections would be incidental and rare

Question 5

List the diseases that were present in pre hominid ancestors

Answer 5

continue to evolve with us today
‣ This included worms, lice, and bacteria like Salmonella (Yaws), Treponema (Syphilis)

Question 6

What was an advantage that hunter gatherers had?

Answer 6

Mobility

put hunter - gatherers within a wide range of food stuffs

◦ This helped establish the kinds and quantities of nutrients humans need today

• Since such variety was characteristic of hunter-gatherers this may partially explain
  anomalies in modern man

Question 7

scurvy

Answer 7

insufficient vitamin C
A ship board disease for 300 - 400 years
30 weeks of Vitamin C deprivation will cause scurvy

Question 8

Can animals/ humans syntehsize vitamin C why or why not?

Answer 8

only a few animals including humans cannot synthesize their own vitamin C

due to ascorbic acid being well supplied in food over 1000s of years

our bodies evolved: we stopped making vitamin c b/c very big molecule a lot of energy and its present in our food so why would we make it

Question 9

List the symptoms of scurvy

Answer 9

Spongy, bleeding gums
‣ Sunken eyes
‣ Old wounds reopen
‣ Death

Question 10

Why was scurvy rare before the 15th century?

Answer 10

humans weren’t on ships for very long times prior to that time period

Question 11

Who was affected by scurvy and why?

Answer 11

sieged armies
prisoner war camps
Irish great potato failure
weren’t fed properly

Question 12

Irish great potato failure (1845-1846)

Answer 12

potato bytes killed off most of crops

government decided to sell off remaining crops of potatoes replaced it with wheat which doesn’t contain vitamin C
as potatoes contain vitamin C and the replacement grain did not

Answer 13

Scurvy
◦ Food contains insufficient Vitamin C (ascorbic acid)
◦ Humans and only a hero other animals cannot synthesize their own ascorbic
acid * Why?
◦ Ascorbic acid is important in metabolic process
◦ Unlikely to be lost via evolution unless it was rendered superfluous ‘well
supplied diet