Announcements
Exams will be ready on Thursday. I have a sudden deadline I
need to meet by the end of this week and have not been able
to finish going through them.
Reading is available from web site. Read it closely by next
Thursday and be prepared to discuss in class!!!
Urban Forestry project, we'll start on campus.
Meet in Rm. 202, as usual, next week.
We'll try some techniques for taking quick digital specimens.
Bring your cameras.
POPULATIONS
‘metapopulations’
genetic diversity is organized on the
landscape by different selection
pressures
SPECIES
Atomic particle – evolutionary unit
Extinction and birth
Binomial taxonomic name
Barriers to gene flow
External or internal
Neutral or selective
Gradual or immediate
SPECIES
Allopatric speciation
Mutations accumulation, limited gene
flow
Sympatric speciation
Thought to be very difficult
Assortative mating
SPECIES
Reproductive isolation mechanisms
Pollinator fidelity and service
Prepollination or post
(prezygotic or postzygotic)
SPECIES
Prepollination – behavior, morphology, selfpollination across strong environmental gradients.
Postpollination (prezygotic) – pollen vigor,
stigmas as selective agents, MHC complex.
Postpollination (postzygotic) – inviability,
abortion, infertility
SPECIES
“Hybridization” is a dirty word amongst most
taxonomists despite the fact that it has been shown
to be advantageous in some circumstances.
“Good” or “bad” species
Many plants remain interfertile after ‘speciation’
SPECIES
The abominable mystery of flowering plant diversity
Latest work on fossil flowers has been quite amazing.
SUPER-SPECIES, SPECIES FLOCK or
SYNGAMEON
“Ring” species
Network of closely related and inter-fertile species
Fuzzy species concept.
COMMUNITY
Shifting ‘selective’ landscapes
“Mast fruiting” in trees
EVOLUTION and ADAPTATION
It is an integration of numerous processes over
long periods of time, during which sudden and
dramatic events occur and change the selective
environment.