1. Patterns of Evolution
Evolution Notes Part 3

2. What is microevolution?
Evolution on a small scale within a single population

3. Natural selection is a mechanism for changes in populations that occurs when organisms with favorable variations survive, reproduce, and pass on traits to the next generation.
Artificial selection is the breeding of certain traits over others.

4. Speciation What causes new species to form?
Reproductive isolation – when populations are prevented in some way from reproducing with each other , their gene pools adapt and evolve separately, causing them to lose the ability to cross breed 4

5. Reproductive Isolation
What causes reproductive isolation?
Geographic isolation – mountains, rivers, canyons
Temporal isolation – active or reproducing at different times of day or times of year
Behavioral isolation – differences in mating rituals that prevent reproduction between groups 5

6. Anatomical
Some adaptations involve changes in the structure of body parts: mimicry and camouflage.
Mimicry enables an organism to copy the appearance of another species.

7. MIMICRY

8. Milk Snake
Coral Snake

9. Anatomical
Some adaptations involve changes in the structure of body parts: mimicry and camouflage.
Camouflage is a structural adaptation that enables an organism to blend in with its surroundings.

10. CAMOUFLAGE

11. Physiological Adaptations
Some adaptations are physiological or changes in an organisms metabolic processes.
Keep in mind that all things are made up of cells and the organelles are structurally and functionally similar in most organisms.

12. Physiological Adaptations
Organisms are constantly changing to adapt to their environment. Take a look at organisms that have been exposed to antibiotic and pesticides. The organisms that survive have become selected because they are physiologically more resistant.

13. Imagine that there are 10 bacteria growing on your hand.

14. You use Germ-x to clean your hand everyday.

15. After 4 days, there are still 3 bacteria on your hands that have survived.

16. Is there anything special about these bacteria. Yes
Is there anything special about these bacteria? Yes..they have something about their DNA that has made them different and strong enough to survive. So now what will happen?

17. Those 3 that are “resistant” will undergo Mitosis.

18. And after a week, your hands will be covered with tons of bacteria that are ALL resistant to Germ-X. 

19. Macroevolution What is microevolution? What is macroevolution?
Large scale evolutionary patterns and processes occurring over long periods of time
Transcends the boundaries of a single species

20. Macroevolution What are the important topics in macroevolution?
Extinction
Adaptive radiation
Convergent evolution
Coevolution
Punctuated equilibrium
Changes in developmental genes

21. Extinction Why is extinction important?
Several times in Earth’s history, mass extinctions wiped out ecosystems
During these events, many species became extinct
Other species took advantage of ecological opportunities as habitats opened up
This produced a burst of evolution

22. Adaptive Radiation What is adaptive radiation?
When a single species or group of species evolve through natural selection into diverse forms that live in different ways

23. Adaptive Radiation What are some examples? Darwin’s finches
Wild mustard variations

24. Convergent Evolution What is convergent evolution?
What are some examples?
Unrelated organisms in similar environments evolve to look remarkably similar to each other
Similarities between Australian marsupials and placental mammals
Similarity in form between dolphins and sharks

25. Coevolution What is coevolution? What are some examples?
Two species evolve in response to changes in each other over time
Plants develop pollination methods that take advantage of insect feeding adaptations, and vice versa

26. Punctuated Equilibrium
What is punctuated equilibrium?
“Rapid” evolution after long periods of equilibrium – often occurs due to isolated populations, migrations, or mass extinctions

27. Developmental Genes What is meant by changes in developmental genes?
Homologous control genes serve similar functions in animals that have not shared a common ancestor in millions of years

28. What should I believe?
Although evolution is widely accepted by scientists and had broad supporting evidence, it is still a theory
Remember, theories are well-supported testable explanations of phenomena that have occurred in the natural world
There are differences of opinion about interpretation and every person is entitled to his or her own opinion – the experts are not always objective
Our goal is to present the prevailing view and allow you to reach your own conclusions
Remember that everyone is entitled to their own opinion – yours is no more right nor wrong than anyone else’s