What is a species?

Question 1

Biological Evolution

Answer 1

Organisms produce more offspring than can survive and reproduce. These offspring have genetic diversity
Organisms that survive are better adapted to their local conditions
Traits in parent are inherited by offspring → SEX AND DEATH
Historical “baggage”: no organism will be perfectly evolved because of conservation of basic body plan, etc

Question 2

Phyletic gradualism

Answer 2

species change more slowly but steadily

Question 3

Punctuated equilibrium

Answer 3

rapid change initiates evolution

Question 4

Morphospecies

Answer 4

defined by unique morphological characteristics → e.g. Linean categorization (species, genus, family, etc)

Question 5

Cladospecies

Answer 5

defined by most parsimonious set of shared characteristics
Cons: convergent evolution

Question 6

Cladistics

Answer 6

the science of cladospecies
Based on parsimonious distribution of shared, derived traits
Created hierarchical groups with implies ancestry

Question 7

Monophyletic group (clade)

Answer 7

contains common ancestor and all descendants

Question 8

Paraphyletic group

Answer 8

group that excludes some descendents
Ex: reptiles, birds (excluding dinosaurs)

Question 9

Polyphyletic group

Answer 9

non-overlapping monophyletic groups
Ex: flying animals

Question 10

Homology

Answer 10

implies common ancestry, does not have to do with function
Ex: bilateral body structure

Question 11

Analogy

Answer 11

convergent evolution, same trait/function evolved independently
Ex: flight in birds and bats