1. Evolution, Natural Selection and the Diversity of Animals

2. How do new species begin? DNA is instructions for all life DNA -  RNA  Protein  Trait Mutations MAY cause changes in the production of proteins New traits can be passed to offspring –May be helpful, bad or cause no change at all

3. Mutations Changes in the DNA sequence of nucleotides: A’s, G, C’s and T’s –Sickle cell anemia – Harmful? Helpful? –Albinism –Cystic fibrosis –Most diseases and deformities –Blond or brunette –2 legs or 4 legs? –Fins or flippers? –Color of skin –All differences!

4. Mutations: the good, the bad, and the indifferent Point mutations – one letter change; substitution Frame-shift mutations – insertion or deletion of one or more nucleotides that “shifts” information; each 3 code for 1 amino acid that makes up a protein EX: cat ate the rat  catatetherat caatatetherat  Caa tat eth era t Ctatetherat  Cta tet her at Not all mutations are bad – some make bacteria ANTI-BIOTIC RESISTANT. Good for the bacteria, not-so-good for you! Some mutations result in no change

5. Mutations can change a population If new traits is advantageous, those w/ trrait will have more successful offspring than those without it Over long periods of time… populations --  new species Fish  w/ lungs  move onto land  reptile  humans! Species = groups that are so similar they can breed with each one another and produce VIABLE (capable of reproducing) offspring. This is Natural Selection.

6. New species can develop if… Members of a populations are separated from each other (GEOGRAPHIC ISOLATION) Members of two populations can no long breed successfully with one another (REPRODUCTIVE ISOLATION) Having an abnormal number of chromosomes (POLYPLOIDY)

7. Divergent Evolution One ancestral species leads to 2 new species Ancestral Green Iguana Marine Iguana Land Iguana

8. Adaptive Radiation One ancestral species leads to 3 or more new species

9. Types of Evolution Two ideas of how new species develop Gradualism: lots of small changes in DNA over long periods of time Punctuated Equilibrium: fewer, larger changes over long periods of time.

10. Gradualism Punctuated Equilibrium 10 million years Notice the results of both are the same: CHANGE

11. Evidence for evolution Antibiotic resistant bacteria Fossils Anatomy Embryology Biochemistry All of these methods are used together to show relationships between species

12. Fossil Record Used to observe early life: Incomplete – only hard parts fossilize in specific types of soil Like a puzzle – overall pattern

13. Anatomy Similarity in structures suggests relationships between animal species Homolgous and Analogous structures – see diagram Vestigial structures – whale pelvis

14. Homologous and Analogous Structures Homologous structures (homo=same) – alike because they are closely related Example: bird wings, bat wings, your arm and hand Analogous structures (not closely related, but same function) - -bird wings and insect wings

15. Embryology sperm + egg fertilization zygote (1 cell) blastula – about 64 cells gastrulation – when blastula begins to fold in –Forms opening into gastrula –gastrula – 2 cells layers = 2 tissue layers archenteron – opening into the gastrula

16. Protostome vs Deuterostome If the archenteron (opening) forms into: a mouth first = PROTOSTOME an anus first = DEUTEROSTOME All invertebrates (no backbone) are protostomes except echinoderms Vertebrates (w/backbone) and echinoderms = Deuterostomes Humans?

17. Living things are grouped according to similarities Embryology The more similar the embryonic development pattern the more closely related

18. Embryology Vertebrate embryos share developmental characteristics: –Post anal tails –Pharyngeal slits or pouches –Notochords –Nerve cords DNA determines these characteristics!

19. Biochemistry All organisms have DNA, ATP, and other enzymes/proteins in common DNA is made of 4 molecules: A,T,C, and G Similar DNA sequences = similar ancestry

20. A cladogram is like a family tree showing how things have changed. Shows relationships based on specific characteristics Everything to the right of this point have Vertebrae Point where common ancestors diverged

21. Living things are grouped according to similarities Kingdom Phylum Class Order Family Genus Species Few similarities Largest # of organisms Most similarities Smallest # of organisms Binomial Nomenclature: scientific names are Genus and Species Ex: Iguana iguana, Homo sapien

22. HOMOLOGOUS structures, humans, birds, porpoises and elephants are considered more closely related to each other than any are to insects. Living things are grouped according to similarities

23. Dichotomous keys Species can be identified using a dichotomous key Series of “either / or” questions leading to the identification.

24. Dichotomous keys Example: 1. Does the flower have white or yellow petals? -if yellow, it is a sunflower -if white, go to question 2 2. Does the flower have a yellow or red center? -if yellow, it is a daisy -if red, go to question 3