EVOLUTION!!!!-Change in the genetic makeup of a population

or species over TIME!!!

Charles Darwin

• Wrote a book called “On the Origin of Species” in 1859.

• Based his hypothesis on observations he witnessed during a 5yr journey around the world.

• Most famous place he went were the Galapagos Islands.

Darwin’s Four Main Arguments

• DESCENT WITH MODIFICATION- All life has descended from one original life form (Bacteria)

• GENETIC VARIATION- Differences exist between every individual in every population allowing for change over time. (DNA mutation)

• NATURAL SELECTION- Based on environmental pressures some individuals are better suited for survival due to genetic variation which means they leave more offspring.

• FOSSILS- This record shows a progression from simple to complex over long periods of time. It also shows similarities and differences between past and present life forms.

Different Tortoise shells on different islands

Finches

Diving Iguanas

Vocab

• Species- organisms that are physically similar and can interbreed to produce fully fertile offspring.

• Speciation- one species gives rise to another due to Geographic or Reproductive isolation causing two gene pools to form.

• Geographic Isolation- Groups become isolated due to changes in their original habitat. (i.e. canyon forms, ocean forms between two land masses).

• Reproductive Isolation- slight variations in breeding habits in similar groups in the same area cause different gene pools to form

Evidence for Evolution Today

• Fossil Record- Shows past forms and has an orderly progression from simple to complex. (Horse)

• DNA- Can look for similarities and differences in whole genomes and in specific proteins like Hemoglobin.

• Vestigial Structures- Things that organisms have that they no longer use like the human appendix or pelvis and leg bones in whales.

• Homologous Structures- Similar structures that are seen in different species showing common ancestry like the bones found in the limbs of all 4 legged creatures (tetra pods) or similarities in embryos

Adaptations

Final QuestionWhere do you stand on the theory of

evolution?

Imagine you were in a debate with someone on the subject of evolution.

Identify 3 main points for your side of the argument and then defend them using specific examples.

There is no right or wrong answer here but you must defend your position.

This if your opportunity to speak openly and honestly on the subject. The goal is for you to incorporate what you have learned in class into your own belief system