Chapter 3: Genes, Epigenetics, and the Environment Flashcards
Chromosome:
Strands of DNA wound around each other in a double-helix configuration. 23 pairs, one coming from each parent.
Gene:
Sections on a strand of DNA (DNA=deoxyribonucleic acid) that code for the protein molecules that affect traits.
Bipedalism:
Ability to move on two legs and hands are free to grasp tools and such.
Encephalization:
Increase in brain size relative to the body (frontal lobes).
Heritability:
A measure of the variability of behavioural traits among individuals that can be accounted for by genetic factors.
Heritability: 0
Behaviour trait due entirely by the environment.
Heritability: 1
Behaviour trait due entirely to genetic inheritance
4 Important Points on Heritability: Heritability is an abstract concept:
It doesn’t tell us what specific genes cause the trait.
4 Important Points on Heritability: Heritability is a population concept:
It doesn’t tell us about an individual. It helps understand the differences in individuals among a population.
4 Important Points on Heritability: Heritability is dependent on the environment:
It is meaningful only for the environment in which the heritability was computed because behaviour changes according to the environment
4 Important Points on Heritability: Heritability is not fate:
It is good for identifying behavioural traits that are influenced by genes but it doesn’t tell us how people will respond to specific conditions.
Monozygotic twins:
Share 100% of their genes. They develop from splitting from a single fertilized egg.
Dizygotic twins:
Share 50% of their genes. They develop from two separate fertilized eggs.
Degree of relatedness:
The probability of sharing genes.
Epigenetics:
Study of environmental influences that determine whether or not genes are expressed, without altering the original DNA sequences that constitute the genes themselves.
