Exam 1 Chapter 1: introduction

Question 1

What is a vertebrate?

Answer 1

• Has body plan including segmented vertebral column, paired appendages dorsal hollow nervous system, and ventral digestive system
• Animal possessing a backbone/spinal column, includes mammals, reptiles, amphibians, fish

Question 2

Name 2 types of biological similarity

Answer 2

homology and homoplasy

Question 3

Homology

Answer 3

o a character shared between species that was also present in their common ancestor

Question 4

Homoplasy

Answer 4

o A character shared by a set of species but not present in their common ancestor
- different kinds of homoplasy include Analogy, Convergent Evolution, and Parallel Evolution

Question 5

Analogy

Answer 5

homoplasy, similar function

Question 6

Covergent Evolution

Answer 6

homoplasy, – set of characteristics due to adaptations to a particular environment; bodies superficially similar (example: sharks and dolphins, similar since aquatic environment)

Question 7

Parallel Evolution

Answer 7

homoplasy, when the similar features are caused by an equivalent developmental mechanism

Question 8

Symmetry

Answer 8

A balanced distribution of duplicate body parts or shapes within the body of an organism
-How an animal’s body meets the environment

Question 9

Two types of symmetry

Answer 9

radial and bilateral

Question 10

Which symmetry characterizes vertberates?

Answer 10

bilateral symmetry

Question 11

Radial symmetry

Answer 11

• organism divided into sections that rotate and match

Question 12

bilateral symmetry

Answer 12

body divided into two equal halves, with halves mirroring each other

Question 13

Segmentation

Answer 13

o The serial repetition of similar organs, tissues, cell types or body cavities along the anterior- posterior (A-P) axis of bilaterally symmetric animals
o Seen in annelida, arthorpoda(most diverse), chordata

Question 14

Preadaptation

Answer 14

o A trait that has evolved for one particular function may come to serve another function

Question 15

Why is preadaptation important to vertebrate evolution?

Answer 15

o It has important role in development of birds
o Feathers on dinosaurs were originally for warmth, but now serve for the purpose of flight in bird species

• Changing/remodeling what exists
• Rarely adding wholly novel structures
• Selection only acts on what’s there

Question 16

What does phylogenetics study?

Answer 16

the study of evolutionary relationships among biological entities –species, individuals or genes (which may be referred to as taxa)

Question 17

What is a phylogeny?

Answer 17

o A visual representation (a hypothesis) of the evolutionary history of populations, genes, or species

Question 18

Describe and understand the set up of a phylogeny

Answer 18

o The tips of the tree represent groups of descendent taxa (often species)
o The root of the tree represents the ancestral lineage
o The nodes represent the common ancestors of those descendants
o When a lineage splits (speciation), it is represented as a branch

Question 19

What is a clade?

Answer 19

groups that include a common ancestor and all the descendants (living and extinct) of that ancestor

Question 20

What are synapomorphies?

Answer 20

o Shared derived characters
o Different from ancestor and shared by 2 or more lineages

Question 21

Monophyletic group

Answer 21

a single common ancestor and all descendants

Question 22

Paraphyletic group

Answer 22

a common ancestor and some but not all descendants

Question 23

Polyphyletic group

Answer 23

based on non-homologous characters