Presentation is loading. Please wait.

Presentation is loading. Please wait.

Evolution pp. 297-301.

Similar presentations


Presentation on theme: "Evolution pp. 297-301."— Presentation transcript:

1 Evolution pp

2 POPULATIONS EVOLVE NOT INDIVIDUALS!
Evolution: change in a population of organisms over time Natural Selection: mechanism that drives evolution POPULATIONS EVOLVE NOT INDIVIDUALS!

3

4 LAMARCK Acquired traits passed on to offspring
“Use it or lose it” hypothesis EX. If giraffes stretch necks (not born with it) to reach higher leaves on trees then the offspring will also have stretched necks. INCORRECT!

5

6

7 DARWIN Darwin stated that newer species are modified versions of older species Darwin best described evolution as descent with modification

8 EVOLUTION IN ACTION Convergent evolution: Organisms with very different ancestors become more alike due to a common environment (i.e fish and whales)

9 Divergent evolution: populations become more and more dissimilar to adapt to the environment
EX. Appearance of birds with different sized beaks that are specific for size of bird seed

10 Co-evolution: as one species evolves another does (parasites and hosts)

11

12 NATURAL SELECTION What causes populations to change over time?
Natural Selection: organisms best suited to their environment live to reproduce and pass on their genes


Download ppt "Evolution pp. 297-301."

Similar presentations


Ads by Google