Transcript Tutorial 2b - data organisation and exploration

Data Handling & Analysis
ZO4030
2012-2013
Andrew Jackson
[email protected]
Basic Data Organisation
• Use Excel to input and organise your data
• Each row is a different observation
species
class
brain
body
New Caledonian Crow
Aves
7.5
277
Emperor Penguin
Aves
46.2
28000
Little Penguin
Aves
7.4
960
African elephant
Mammalia
6000
5000000
Bottlenose Dolphin
Mammalia
1700
160000
Propose an hypothesis
• That the mass of brains of mammals
(Mammalia) are different to the brains of birds
(Aves)
– Identify the Response Variable
– Identify the Explanatory Variable(s)
species
New Caledonian Crow
Emperor Penguin
Little Penguin
African elephant
Bottlenose Dolphin
class
Aves
Aves
Aves
Mammalia
Mammalia
brain
7.5
46.2
7.4
6000
1700
body
277
28000
960
5000000
160000
Calculate new response variable
Explanatory Variable
Response Variable
species
class
brain
body
ratio
New Caledonian Crow
Aves
7.5
277
0.027076
Emperor Penguin
Aves
46.2
28000
0.00165
Little Penguin
Turkey
Magpie
Pigeon
Ravan
Mallard
Aves
Aves
Aves
Aves
Aves
Aves
7.4
7
5.3
2
15
5.8
960
5500
215
300
1200
1252
0.007708
0.001273
0.024651
0.006667
0.0125
0.004633
Jaguar
Mammalia
157
100000
0.00157
Rhesus monkey
Mammalia
179
6800
0.026324
Golden hamster
Mammalia
1
120
0.008333
Grey wolf
Mammalia
119.5
36330
0.003289
Brain / body mass ratio
How will we plot these data?
Aves
Mammalia
Questions
• Biological question
– Does brain size differ between birds and
mammals?
• Data question
– Is the mean ratio of brain to body mass different
between the birds and mammals?