1. Unit 7

5. Charles Darwin 1831 – Unpaid naturalist - HMS Beagle Explored coastlines for ~5 years Noticed that many plants & animals on the Galapagos Islands looked like those on the South American coast Also noticed finches in different areas with different beaks

7. Malthus - 1798 Every organism has the potential to produce many offspring Only a limited number of offspring survive and reproduce Population – interbreeding individuals of a species that live in the same geographical area

8. Darwin Individuals with traits better suited to ENVIRONMENT more likely to survive and reproduce When they reproduce, the number of individuals in the population with this trait will increase This is evolution by natural selection

9. UNDERSTANDING CHECK

10. More of Darwin’s Conclusions Organisms differ from place to place because habitats present different challenges ENVIRONMENT is the driving force behind evolution

11. 1859 – On the Origin of Species… Controversial because… Species change  new species Apes are close relatives of humans

12. 1859 – On the Origin of Species… Supported by… 1. Inherited variation exists within genes of every population or species 2. In a particular environment, some individuals are better suited to survive and reproduce

13. 1859 – On the Origin of Species… Supported by… 3. Over time, traits that make some individuals better tend to spread in that population 4. LOTS of fossil evidence that living species evolved from organisms that are now extinct

14. Recent Updates Reproductive isolation can lead to populations becoming different species Rate of evolution Gradualism – Darwin - slow & steady Punctuated equilibrium – Stephen J. Gould – short bursts followed by nothing

15. Recent updates Selective pressure can increase the speed of evolution Bacteria & antibiotic resistance Natural selection can lead to a change in gene frequency over time

16. UNDERSTANDING CHECK

17. Evidence of Evolution 1. Fossils 2. Anatomical comparisons 3. Developmental patterns 4. Nucleotide sequences

18. Fossils Relative dating – Location in sedimentary rock Absolute dating – Radioactive/radiometric dating to determine age Transitional forms Can infer lifestyle from structure s

19. Herbivore vs. Carnivore

20. Land vs aquatic vs aerial

21. Nocturnal vs diurnal

22. Anatomical Comparisons Analogous structures – similar functions, different origins Homologous structures – different functions, similar origins Vestigal structures – no function – remnant of evolutionary past

23. Analogous Structures

24. Homologous Structures

25. Development Patterns – show common ancestry

26. Nucleotide Sequences DNA sequence of nucleotides makes you who you are So the more alike the DNA sequence of 2 individuals is, the more closely related they are Chimpanzees & human 98.6% identical

27. More Vocab Divergence – one species changes over time to become 2 different species Speciation – Process by which new species form