Lesson 8

Question 1

Charles Darwin

Answer 1

Theory of Evolution

Question 2

Heritable

Answer 2

Trait is part of the genetic code and can be passed down to offspring.
- However, genetic mutation is a source for random heritable traits

Question 3

In order for selection to occur on any given trait

Answer 3

there must be variation in that trait in a
population.

Question 4

Advantage (Differential Success)

Answer 4

Certain traits may be desirable over the years, affecting reproductive opportunities.

Causes evolution and bitch you know this

Question 5

Competition

Answer 5

Limited resources will be competed for.

Question 6

Four Basic Principles of The Theory of Evolution:

Combine to?

Answer 6

1. Heritability
2. Advantages
3. Variation
4. Competition

competition for limited resources -> Success of certain variations of a heritable trait -> gradual evolution of trait in pop -> increases organisms survival and reproduction and better adaptability to environment

When enough new traits appear then they can be considered a new species

Question 7

Natural Selection

Answer 7

Competitive selective process by which bad traits are rid of and good traits are retained

Question 8

Shared common ancestors

Answer 8

Organisms can be grouped together based on this.

eg) Orinthiscia and Saurischian evolved from a single dinosaur species (seperately.)

Question 9

Character

Answer 9

Any heritable trait that can be described and labeled

Question 10

Shared Derived Character

Answer 10

Character that is present in two or more groups and their common ancestor
- But, not present in distantly related groups (eg) spinosaurus and Ouranosaurus))
- also called shared derived character

eg) predentary bone in ornithischians

Question 11

Spinosaurus

Answer 11

Theropod (saurischian-forwards)
- long snout, sharp teeth, clawed fingers, back vertebrae sail

Question 12

Ouranosaurus

Answer 12

Iguanodont {orinthiscian-backwards)
- beak, grind teeth, hoof, back vertebrae sail

Question 13

Convergent evolution

Answer 13

Evolution of similar traits in 2 different lineages
- results when two lineages adapt to similar environments

eg) spinosaurus and Ouranosaurus

Question 14

Thyreophora

Answer 14

Osteoderms
- orinthisichia

• eg) stegosauria and ankylosauria*

Question 15

Marginocephalia

Answer 15

Back of skull expanded into shell or frill

eg) ceratopsia and pachycephalosauria

Question 16

Parsimony

Answer 16

“All other things being equal, the simplest answer is usually the right one”
- Occam’s Razor

Family tree with the fewest number of evolutionary changes is probably the right one.

simpler to assume that the one character in common b/w Ouranosaurus
and Spinosaurus is result of convergent evolution, than it would be to assume that the huge number of similarities between Ouranosaurus and iguanodonts are all the result of convergence

Question 17

phylogenetic trees

Answer 17

Family tree

• computer analyzes list of characters compiled by researcher (character matrix)
• computer applies parsimony principle to arrange organisms in sequence of relationships that require fewest instances of convergent evolution
• composed of nodes and branches

Question 18

Node

Answer 18

Where two branches diverge
- shows point which two lineages has shared common ancestor
- after a node, pattern of subsequent branches and nodes show how descendants of common ancestor continue to diverge from eachother

Question 19

Clade

Answer 19

Group of species that share common node
- Must contain ancestor of group and all descendants
- no limit or minimum
- eg) birds

Question 20

Archaeopteryx
and who coined it

Answer 20

Thomas Henry Huxley recognized birds evolved from dinosaurs.
- birds are branch of family tree and that transitional forms do exist

Archaeopteryx: missing link between dinosaurs and birds
- fossil lake deposits
- feather, tails, teeth, clawed fingers, tail vertebrae

Question 21

Sinosauropteryx

Answer 21

First non-avian dinosaur to be discovered with feathers
- feathers used for insulation

Question 22

Yutyrannus

Answer 22

Late tyrannosauroid with feathers

Question 23

What are the 4 possible definitions of birds?

Answer 23

1. Archaeopteryx and all of its descendants
Problem: New phylogenetic analyses sometimes show that archaeopteryx is more closely related to dromaeosaurid theropods than modern birds

2. Feathered Dinosaurs
Problem: many dinosaurs have feathers, like tyrannosaurs?

** 3. Flying Dinosaurs**
Problem: Difficult to determine which dinos were capable of so (as opposed to simply gliding)

4. Crown Dinosaurs: last common ancestor of all extant birds and its descendants. *This is the favoured name. And then Avialae is the Claude name used for #1.
Problem: Fails to recognize many feathered/flying dinosaurs that are more closely related to modern birds than to archaeopteryx as birds.

Question 24

What are the three Lambeosaurine Hadrousaurs? What do they share in common?

Answer 24

Lambeosaurus, Corythosaurus, Parasaurolophus

Crest is formed from the same bones and is hollow. skulls have wide beak and modified dental battery.

Question 25

Liaceratops

Answer 25

Early Ceratopsian w/ no horns but a frill.