Lecture 3: Speciation, Taxonomy, and Phylogeny Flashcards
What are the basic units for macroevolution?
Species.
What is a species definition in Biological Species Concept?
Species are reproductively isolated from other species. Based on gene flow.
List isolation mechanisms.
Geographic isolation, differences in behaviour, physical appearance, # of chromosomes, etc.
What is gene flow?
The movement of genetic material within or between populations.
What is an Ecological Species Concept?
It’s not barrier to gene flow, but natural selection that maintains differences between species.
What is the species definition for Ecological Species Concept?
a lineage that occupies an adaptive zone (ecological niche) different from that of any of other related lineage.
Why does Ecological Species Concept believe it is not just gene flow dictates what a species is?
Because certain common species live in different geographic region without gene flow, but are the same species. Natural selection more utilized because hybrids can be created but not optimum.
What is the process towards a new species called?
Speciation.
What are the three types of speciation?
Allopatric, parapatric, sympatric.
Explain allopatry.
Two or more populations of a single species become geographically separated, resulting in divergence to two different species.
Explain parapatric.
Not complete geographic isolation, but range results in different environments and the species begin to have limited overlap.
What are two methods that amplify allopatric speciation?
Character displacement and reinforcement.
Explain sympatry.
Overlapping ranges, where difference between sub-groups result without geographic isolation.
Which two people suggest that speciation occurs in rapid, infrequent changes (spurts)?
Gould and Eldredge.
What is phylogeny?
Family trees of species.
What is taxonomy?
Using phylogeny to name and classify organisms.
What is the comparative method?
Using phylogeny to find if a trait was simply inherited or needed for its current function.
What is the name for ancestral traits? Derived trait?
plesiomorphic (primitive) occur in last common ancester, apomorphic, newly evolved.
What is cladistics?
Members of group have unique features that they have in common, proving they are close in ancestry.
Difference between homologous and analogous.
Homologous: same trait shared between organisms due to common ancestor.
Analogous: Similar trait but due to similar function, not ancestry.
What is neutral theory?
Most mutations to genes don’t do anything.
What are the two philosophies for taxonomy?
Cladistic taxonomy and evolutionary taxonomy.
