Speciation & Macroevolution Slide 2 Species What is a
species? Slide 3 Speciation Microevolution Speciation
Macroevolution Slide 4 Reproductive Isolation Reproductive
isolation Classified as: - Prezygotic mechanisms - Postzygotic
mechanisms Slide 5 5 Prezygotic Mechanisms 1. Groundhog lives in
fields at lower elevations Marmot lives in alpine meadows Slide 6
Prezygotic Mechanisms Contd 2. Day and night-blooming cacti Slide 7
Prezygotic Mechanisms Contd 3. 4. Insects of a particular size and
shape can enter the Pink Lady Slippers sac to get pollen Slide 8 5
Prezygotic Mechanisms 5. Coral reefs release sperm and egg. Those
from same species will fuse together Slide 9 3 Postzygotic
Mechanisms Different species may produce a hybrid 1.Zygotic
mortality 2. Hybrid inviability Slide 10 3 Postzygotic Mechanisms
3. + horse donkey Mule - infertile Slide 11 Modes of Speciation
Allopatric Speciation Slide 12 Modes of Speciation Sympatric
Speciation Frogs live in same habitat but 1 is diploid, other is
tetraploid What does that indicate about their evolutionary
relationship? Slide 13 Divergent Evolution Divergent Evolution
Slide 14 Convergent Evolution Convergent Evolution Why would this
occur? Slide 15 Rates of Evolution Theory of Punctuated Equilibrium
- Species evolve drastically in rapid bursts of change (evolution
time) followed by long periods of no change - Transition fossils
are rare Theory of Gradualism - Many small changes accumulate over
time to produce a different species - Gradually become distinct
from parent generation - Transition fossils are common Slide 16
Rates of Evolution Both theories are widely accepted Slide 17
Co-evolution Co-evolution Plants require bees to disperse pollen.
To attract bees produce sweet nectar Slide 18 Plants and
Herbivorous Insects Monarch caterpillar tolerates milkweeds toxins
and can store it in its tissues to make itself poisonous to others
Slide 19 Slide 20 Does Evolution Always Produce Perfect Organisms?
Any other examples weve discussed?
