Bio 181 1st Edition Lecture 7Outline of Last LectureI. Mechanism of EvolutionII. 2 factors of EvolutionIII. Genetic DrifOutline of Current Lecture I. SpeciationII. Patterns of SpeciesIII. Patterns of SpeciationIV. Rates of SpeciesCurrent LectureI. Speciation (Macroevolution)a. level of change in organism that create new species and groups of speciesi. occurs due to accumulation of microevolutionb. different species of families that we see as the samei. 9 species of giraffesii. different species don’t breed with each other naturaliii. genetically differentc. Speciation: occurs due to accumulation of macroevolutioni. formation of different speciesd. Species concepti. identify by having a unique combination of traitsii. phylogenetic: history of different species1. use physical traits2. DNA sequencesiii. Polyploidy: doubling of chromosome numberiv. Biological: have the potential to interbreed in nature to produce viable and fertile offspring1. lager: seen as violent and don't produce fertile offspring2. problemsa. hard to identify if they don't produce due to geographicalisolation, may belong to same speciesb. ex: brown bears and polar bear similar genetic but can still mate with each other are they differentv. Evolutionary species1. not really used by itselfThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best Used as a supplement to your own notes, not as a substitute.vi. Ecological species: each species occupy an ecological niche1. mainly seen in bacteriaII. Reproducing Isolation Mechanisma. create new species due to separationb. temporal isolation: never come in contact with each other mate at different timesi. some fruit flies breed at night some in the dayc. Behavioral isolationi. ex: satin bower bird: makes a bower and decorate its with different color and that attracts the female and they mateii. female looking for a certain type of maleiii. fiddler crab the way it waves its claw attracts the female and lets her know her speciesd. Mechanical isolationi. can only mate with a female with the correct fitii. seen in insectsiii. incompatible sex organse. Gametic isolationi. egg and sperm can only mate with same speciesii. seen in plantsf. ecological/habiti. species have been separated because the use of different habitatii. only mate with those in same habitatg. Postzygotic isolation mechanismi. after matingii. zygotic mortality/ unviabilityiii. hybrid sterility1. seen in mules2. horse and donkey cannot breed same species3. hybrid breakdown- weak, low fitness , high mortality rate amongoffspringa. ligerh. Prezygotic: before matingIII. Patterns of Speciationa. Anagenesis: cause the sequence of speciesi. seen a lot in bacteriab. Cladogenesis: cluster of different species all derived from single common ancestorsc. 3 ways of Geographic speciationi. allopatric speciation: different homeland1. geographic separation of population2. different geographic isolation results in new species3. gene flow with population slow or stop4. can be caused by breakup in island but if brought together do not recognize each othera. ex: pork fish5. Adaptive radiation: one group spreads into new places and gainnew adaptations6. often in different island7. if Cladogenesis has occurred than adaptive radiation has occurreda. is a resultii. Parapatric Speciation: near each homeland1. reproductive isolation happens in neighboring populations2. near each other nut environments are a bit different, so gain different adaptation and can’t breed with each otheriii. sympatric speciation: same homeland1. a new species comes about in the same place a parental species2. seen in plantsa. ex: change in chromosomes causes genetic changes that lead to reproductive isolationb. Cichlid Fish in lake Victoriac. two different species formed because female more likelyto mate with these fish on the bottom of the lake with more reddish tintd. change in ecology, like different eating patterns related to size causing mating preferencesIV. Rates of Speciesa. Punctuated equilibrium: speciation happens in burst and those with more deviation survive thisi. sudden change ii. quicker pace of evolutionb. Gradualism: gradual change in speciesi. slower pace of evolutionii. many transitional formsc. Now we use a concept of both rates to explain evolution:d. Microevolution is the process consistently occurring gradual over time then something in the environment takes place, Macroevolution is present and more rapid change occurs, known as punctured equilibrium and change in species is