Lecture 1

Question 1

Traditional health sciences and biology: what kind of answers do they look for?

Answer 1

proximate answers (HOW?): mechanisms

Question 2

Ecology and evolution find what kind of answers?

Answer 2

ultimate answers (WHY?): origin and function

Question 3

Evolutionary Medicine (EM)

Answer 3

EM = theoretical frameworks of ecology and evolution applied to the study of health and disease

Question 4

what is human ecology?

Answer 4

the study of humans as a mammalian species that attempts to achieve its basic biological goals while it interacts (affects and is affect by) with its ecological context

Question 5

what are basic biological goals?

Answer 5

survival and reproduction

because these two goals lead to evolution

Question 6

what is evolution and how does it occur?

Answer 6

A change in the genetic make up of a population between cohorts

Occurs:
- natural selection
- genetic drift
- gene flow

Question 7

Natural selection

Answer 7

Natural selection is a process

Individuals within a species vary:
- some of that variation is linked to genetic differences
- and some of that variation is linked to differences in survival and reproduction

Question 8

How does the natural selection process work?

Answer 8

• original population
• variation in survivorship
• surviving population of reproductively mature population
• variation in reproduction
• next generation of population

In its essence, it is a simple statement about rates of reproduction and mortality: Those individual organisms who happen to be best suited to an environment survive and reproduce most successfully, producing many similarly well-adapted descendants.

Question 9

Why does the natural selection process take place?

Answer 9

• it is a consequence of differences among individuals in their ability to survive and reproduce in a given ecological context

Question 10

What kind of traits can NS affect?

Answer 10

• ONLY genetically heritable traits

Heritability estimate (H) = Vg/Vp
Vg the variation in genotype
Vp the variation in phenotype

• Heritability varies from 0 to 1, with 0 representing resemblance between two individuals chosen at random

Question 11

can traits associated with health and disease be linked to survival and reproduction?

Answer 11

Of course

so could any of these traits been favoured/disfavoured by natural selection?
YES

Question 12

Some limits of NS

Answer 12

• NS favours reproductive success not comfort or happiness
• some “genes” (portions of genetic material) may be associated with both costs and benefits
• we compete with pathogens which have shorter life spans
• the environment in which we live is dynamic
  environment = ecological context

Question 13

what is ecological context?

Answer 13

Refers to the intricate relationships between living organisms and their physical environment, emphasizing how these interactions shape the ecosystems

Question 14

what encompasses the human ecological context?

Answer 14

• physical environment
• socio-cultural environment

Question 15

human ecology

Answer 15

studies how we attempt to survive and reproduce while adapting to environmental changes

investigates the relationship between environmental and biological variability between individuals

Question 16

are we humans all equally exposed to all changes and challenges?

Answer 16

not necessarily
- prenatal exposures
- postnatal exposures

Some of these different exposures can be observed within a family, others between different families within a community, others between different regions within a country and so on

Question 17

could human ecology focus ONLY on the current environment?

Answer 17

No

Question 18

to summarise human ecology

Answer 18

human ecology studies humans as they attempt to achieve their biological goals within their present context understanding the constraints imposed by our evolutionary past

human ecology also studies the origin of biological variability between and within individuals and populations

the study of humans as a mammalian species that attempts to achieve its basic biological goals while it interacts with its ecological context

Question 19

Genotype vs Phenotype?

Answer 19

• Genotype is the combination of alleles that they possess for a specific gene.
• Phenotype is the combination of their observable characteristics or traits.
• Genotype is directly inherited from its parents, phenotype is merely influenced by genotype.
• Environmental factors can also affect phenotype.

Question 20

Genotype example

Answer 20

• eye colour
• hair colour
• height

Question 21

Phenotype example

Answer 21

environmental factors that influence phenotype are nutrition, temperature, and stress

another is skin colour - our genes control the amount of melanin we produce, but the environment we are in influences our sun exposure therefore determining our skin colour