Reproductive Isolation

1
(No Transcript)
2
Reproductive Isolation
Pre-Zygotic prevent fertilization from ever
occurring 1. Temporal different breeding
seasons (frogs) 2. Habitat different areas
(meadows vs. stream side) 3. Behavioral
different courtship (bowerbirds) 4. Mechanical
different reproductive structures (flowers) 5.
Gametic different sperm-egg binding sites
3
(No Transcript)
4
Reproductive Isolation
Pre-Zygotic prevent fertilization from ever
occurring 1. Temporal different breeding
seasons (frogs) 2. Habitat different areas
(meadows vs. stream side) 3. Behavioral
different courtship (bowerbirds) 4. Mechanical
different reproductive structures (flowers) 5.
Gametic different sperm-egg binding sites
5
(No Transcript)
6
Reproductive Isolation
Pre-Zygotic prevent fertilization from ever
occurring 1. Temporal different breeding
seasons (frogs) 2. Habitat different areas
(meadows vs. stream side) 3. Behavioral
different courtship (bowerbirds) 4. Mechanical
different reproductive structures (flowers) 5.
Gametic different sperm-egg binding sites
Post-Zygotic prevent functioning adulthood 1.
Hybrid Inviability arrested development 2.
Hybrid Sterility adult not able to
reproduce 3. Hybrid Breakdown F2 sterility
7
(No Transcript)
8
Allopatric Speciation
9
Sympatric Speciation
10
(No Transcript)
11
Cladogenesis 1 - many
Anagenesis 1 - 1
Species A
Species A
12
(No Transcript)
13
(No Transcript)
14
Adaptive Radiation lots of open niches leads to
rapid speciation
15
(No Transcript)
16
Getting the Terms Straight
Cause of Speciation pre- and post-zygotic
reproductive isolation
Mechanism of Speciation allopatry vs. sympatry
Pattern of Speciation anagenesis vs. cladogenesis
Pace of Speciation gradualism vs. punctuated
equilibrium
17
(No Transcript)
18
Accumulation of small changes??
19
Exaptations
20
Paedomorphosis Neotony
21
Developmental Genes (Hox)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
Biodiversity Why should we care?
Improves air quality
Pharmaceuticals
Building materials
Disease control
Improves soil fertility
Pest control
Genetic diversity of agricultural species
Helps stabilize ecosystems
Water purification
Textiles
Dyes, rubber, other industrial and raw materials
Prevents erosion
Pollination
Nutrient recycling
Maintains food sources
Aesthetics Spirituality
28
(No Transcript)
29
Terms to get straight Reproductive Isolation
(and types) Methods of preventing reproduction
between organisms. (See prior slide for
types.) Allopatry vs. Sympatry Mechanisms of
speciation. Allopatry involves speciation with a
physical barrier while sympatry is speciation in
the same area. Anagenesis vs. Cladogenesis
Patterns of speciation. Anagenesis begins with
one species and ends with one species while
cladogenesis begins with one species and ends
with more than one species. Gradualism vs.
Punctuated Equilibrium Evolutionary paces.
Gradualism involves small, continual changes
resulting in smooth lineages while punctuated
equilibrium involves long periods of stasis with
rapid speciation. Adaptive Radiation Rapid
speciation in response to recently open niches.
Quick exploitation of new, underutilized
resources. Mechanisms for Major Change
Exaptation, Neotony, Paedomorphosis, Hox genes
30
(No Transcript)