Lecture 2. Genetics
Gregor Mendel (1822-1844)
Mendel
and Garden
Peas
Gregor Mendel
(1822-1844)
and Garden
Peas
Parent plant 1
Parent plant 2
Offspring: F1
DNA
DNA (deoxyribonucleic acid)
contains genetic material
The Bases
Adenine
Guanine
Cytosine
Thymine
Watson and Crick (1953)
Chromosomes
Mitosis
Meiosis
How are traits transferred to
offspring?
Parents
gametes (1n)
Offspring
gametes (1n)
Punnett Square
Fruit fly (Drosophila melanogaster)
Behavioural Genetics
Interdisciplinary field of studies which
focuses on the interaction of genetic factors
with the environmental factors in the
shaping of behaviour
0
1
Environment
Genes
Heritability
The statistical estimate of the proportion of total
variance (variation) in a trait that is attributable to
the genetic variation within a group
H = Vgen/Vpop
Venv=Vpop-Vgen
H - heritability; Vpop - total variability in a population; Vgen variability attributable to genetics; Venv - variability
attributable to the environment
• Manipulate genetic
differences (e.g.
different strains), keep
environment constant :
E
Genetic type
A
a
+
+
Concl.: genetic differences not important
E
+
-
Concl.: genetic differences important
• Keep constant genetic
structure (e.g. same
strain) and provide
different environments
Environment
E
A
+
e
+
Concl.: genetic influence important
A
+
-
Concl.: environmental influence important