1. Patterns In Evolution

2. Two Major Patterns Observed
MACROevolution
And
microevolution

3. Macroevolution
Macroevolution: evolution of groups larger than an individual species. Takes a long period of time

4. Macro= looking at bigger sections of evolution

5. The 6 Patterns that influence how macroevolution occurs are…
1-Mass Extinctions -
2-Adaptive Radiation
3-Convergent or Divergent Evolution
4-Co-evolution
5-Punctuated Equilibrium
6-Gradualism

6. Mass Extinction
Loss of complete huge number of species and ecological systems
Causes could be:
large asteroid during the Cretaceous period l throwing huge amonts of dust and vapor altering global climate affects organisms…like dinosaurs
Volcanic eruptions, continental shifts, changing sea levels, other major environmental changes

7. Adaptive Radiation
A single species or a small group of species evolved into several different forms and live in different ways
Darwin’s Finches

8. Convergent Evolution Unrelated organisms come to resemble each other
This effect is due to different organisms undergoing adaptive radiation in different places BUT in ecologically similar environments
Face similar environmental demands
Examples: streamlined bodies and flippers of water organism ( shark, dolphin, seals, penguins)

9. Convergent Evolution

10. Divergent Evolution
Because of different environments organisms begin to look more and more different over generations
Ex) Dog and Wolf

11. Coevolution
Two species evolve in response to each other due to ecological interactions
Flowers and insects(Madagascar orchid and hawk moth)
Plants and plant eating insects: plants have developed poisons to prevents plant eating insects from feeding on them. Natural selection in insect eating plant favored variants that could alter, inactivate, or eliminate the poisons both organisms change in response to each other

12. Coevolution

13. Macroevolution is also influenced by… RATE
Rate= how quickly the evolution occurs
Quick= Punctuated Equilibrium
Gradual= Gradualism

14. Punctuated Equilibrium
Pattern of long, stable periods interrupted by brief periods of rapid changes. Punctuated on the right

15. When does this type of evolution occur?
Small populations become isolated from the main part of the population .Population changes quicker because genetic changes can spread more quickly among fewer organism
Small group of organisms migrate to a new environment GALAPAGOS FINCHES

16. Gradualism
slow change in a population over a long period
of time

17. Microevolution Quick change in gene frequency within a population.
Quicker then macroevolution.
observed over short periods of
time
Examples: Antibiotic resistance,
Pesticide resistance

18. Antibiotic resistance
Bacteria can evolve quicker when they are resistant to the antibiotic. This is because of genetic shuffling due to their quick reproduction rateswhich means more chances for mutation (changes) less likely to be killed by antibiotics if they have changed their genes SO SMART!!

19. Microevolution example
Imagine that you go to the mountaintop this year, sample these beetles, and determine that 80% of the genes in the population are for green coloration and 20% of them are for brown coloration. You go back the next year, repeat the procedure, and find a new ratio: 60% green genes to 40% brown genes.
You have detected a micro evolutionary pattern: a change in gene frequency. A change in gene frequency over time means that the population has evolved.

20. What caused the microevolution?
Mutations in genes
Migration of organism
Genetic Drift of alleles
Natural Selection of the environment for a given trait