Lecture 16: Disease and population dynamics

Question 1

True or Flase:

Fecundity Schedule only tracks Male matting patterns, and the number of mates they take on.

Answer 1

False:

A Fecundity schedule only tracks females, with sex ratios almost always being 1:1

Question 2

What is a Fecundity schedule?

Answer 2

a tabulation of birthrates

for females of different ages in a population

Question 3

What is Net reproductive rate?

Answer 3

The average number of offspring produced by an individual in a population.

Question 4

What is Geometric rate of increase?

Answer 4

The ratio of the population size at two points in time.

Question 5

What is Generation Time (T)?

Answer 5

The average age within a population at which a female gives birth to her offspring. Can be greater than age of first reproduction if female reproduces more than once.

Question 6

What is the relationship between organism size and generation time?

Answer 6

The larger the organism the longer the generation time.

Question 7

What is the Per-capita rate of increase?

Answer 7

Equal to per-capita birth rate minus per-capita death rate.

Question 8

If per capita rate of increase is greater than 0, then what is happening to the population?

Answer 8

It is growing

Question 9

If the per capita rate of increase is less than 0, then what is happening to the population?

Answer 9

It is shrinking

Question 10

What is the impact of disease upon a population?

Answer 10

Disease can alter individual fitness and impact population dynamics.

Question 11

What is a disease?

Answer 11

A “atypical” condition in a living organism that causes some sort of physiological impairment.

Question 12

What can cause a disease?

Answer 12

Genetic abnormalities, exposure to toxins, and interaction with other organisms,

Question 13

All disease-causing organisms are _____/_____.

Answer 13

Exploitative/selfish

Question 14

What is Direct transmission?

Answer 14

Transmission through physical contact with an already infected host.

Question 15

What is indirect transmission?

Answer 15

transmission through touching a surface that physically touched an infected individual.

Question 16

What is horizontal transmission?

Answer 16

Transmission among individuals of the same generation

Question 17

What is vertical transmission?

Answer 17

Transmission from one generation from another ( parent to offspring )

Question 18

Evolution by natural selection requires that traits be _____

Answer 18

heritable

And traits must produce different levels of fitness among genotypes.

Question 19

What is Disease fitness?

Answer 19

The fitness (measured as net reproductive rate) of a disease.

Question 20

For Horizontally transmitted disease, the number of hosts are proportional to what?

Answer 20

number of
new hosts is proportional to the number of
disease progeny (It isn’t dependent on the
fitness of the host.)

Question 21

For vertically transmitted diseases, what is the Number of hosts dependent upon?

Answer 21

number of

new hosts is dependent on host fitness.

Question 22

Review diagrams on slides 25-26

Answer 22

D O I T

Question 23

What is Isolation?

Answer 23

Separate sick individuals

from healthy individuals

Question 24

What is Quarantine

Answer 24

Separate individuals who have
been exposed to the illness, even if
they are not presenting any
symptoms of the disease.

Question 25

What is better isolation of Quarantine?

Answer 25

Isolation is often better for smaller outbreaks.

As soon as they get larger, then a mixture of both becomes the most effective.

Question 26

How do we stop the spread of disease?

Answer 26

Vaccines

Question 27

What is Herb immunity?

Answer 27

It is when vaccination rates
are high enough that the population growth rate
(r) of the pathogen is negative, and it may go
extinct.

Question 28

Why are diseases with high
transmission rates so hard to
eradicate?

A. It is more difficult to make vaccines for highly
transmissible vs. less transmissible diseases

B. While highly virulent, they have small
populations that are difficult to find and
remove

C. They have high population growth rates,
making it hard to achieve herd immunity

Answer 28

C. They have high population growth rates,

making it hard to achieve herd immunity