1. Changing environments
EVOLUTION
Changing environments
&
adapting species

2. What makes a species?
A species is a group of similar organisms which can mate and produce fertile offspring.
Some different species can mate, but their offspring are usually sterile.

3. Infertile interspecies offspring
Liger = offspring of lion and tiger
Mule = offspring of horse + donkey

4. Interspecies exceptions
There are a few exceptions: Dog can mate with wolf & have fertile pups. These are considered different species based more on DNA and behavior differences.

5. Ways to Change…
Every species has inheritable variation in it’s genome, meaning that no two members’ genes are exactly alike, and some genes result in better adaptations than others.
Adaptations are any traits that help an organism survive, compete, and pass on its genes to its offspring.
This can be caused by many factors.

6. Examples of Adaptations
Camouflage helps prey hide and predators sneak.
Fur, blubber, & other insulation help for survival in cold.
Sweating, panting, and large ears help disperse heat in hot climates.
Ability to access food.
Ability to attract mates.

7. Who will Survive the winter outside?
naked or furry?

8. Who would survive predators?

9. Who would survive predators?

10. Peppered Moths in England
Before the Industrial Revolution, light colored peppered moths were more common than the dark variety.
After coal pollution put a layer of soot on the buildings and trees, dark moths had an advantage, as they were now better camouflaged, and light moth populations declined as predators ate them.

11. Who will survive the food shortage?

12. Who is more likely to get a sunburn, & perhaps skin cancer?

13. Who will pass on their genes?

14. Why would a female be attracted to this guy?

15. “Who will pass on their genes?”
That is the ultimate question in evolution.
Natural selection is all about surviving Mother Nature and outcompeting for resources and mates.

16. Natural Selection: a.k.a. “Survival of the Fittest”
When natural conditions
(climate, predators, competition, and other environmental factors)
determine which individuals are most fit to survive and breed, passing those genes on to offspring.
Charles Darwin first proposed this idea.

17. Artificial Selection: a.k.a. “Survival of the most Desired”
When humans determine which individuals to breed, hopefully passing genes for desired traits
on to the next generation.

18. Dog Breeds- One Species, many specialties
Which would you choose to track down a missing person?

19. Dog Breeds- One Species, many specialties
Which would you choose to pull a
dog sled?

20. Which seeds would you plant?

21. Which cow would you breed at your dairy farm?

22. Which flower would you pollinate for your flower shop?

23. This change in a species over time (many generations) is EVOLUTION!
Whether nature or humans choose who survives and who breeds,
it is by these selection processes that all species change slightly each generation, as certain forms of a gene are favored over others.
This change in a species over time (many generations) is EVOLUTION!