Lecture 1 Flashcards
Define phylogeny
Phylogeny refers to the evolutionary history of a taxonomic group of organisms. It shows the relationships between groups of organisms (taxa) particularly the differences and similarities among them.
What is a node on a cladogram?
A hypothetical common ancestor
What are fossils?
Remains of the bodies or behaviour of extinct organisms
What percentage of species do fossils represent?
only represents about 3% of the species that lived, at best
What is the hardest substance in the body?
Enamel (it is 98% mineral).
The size of the ________ is closely related to the size of the organism.
Size of the teeth is closely correlated with the size of the organism.
What is a synapomorphy?
It is a shared derived trait
The shape of teeth is directly related to the physical properties of what?
Shape of teeth is directly related to the physical properties of the primary food stuff.
Why do big terrestrial organisms have bones?
If you’re big and you don’t have any bones then your muscles don’t have anything to pull against. It works in the water with big animals because water supports them but on land you need bones to move around! Your bones act as levers
How can we see where muscles were attached by looking at a fossilised bone?
Muscles leave scars on the bones so we can see where muscles were attached by look at the shapes of bones and the marks on bones.
Name the two types of bone.
Endoskeleton and Ectoskeleton
Name the two parts of the skull
Cranium and mandible
Name the two functions of the skull
1) To house the sense organs and brain
2) Ingestion and mechanical processing of food
Why are the sense organs housed near the mouth?
The mouth is the most important part of the body because that’s where the energy goes in so this is why the sense organs are housed near the mouth!
Name the two sections of the postcranial skeleton and what they are made up of
1) Axial skeleton: vertebrae and ribs
2) Appendicular skeleton: limbs and limb girdles
What is taphonomy?
The study of the laws of fossilisation.
What is the essential element of fossilisation?
Burial
Provide the key steps for fossilisation
1) Death
2) Burial
3) Fossilisation
4) Exposure
5) Discovery