10/15 Daily Catalyst Pg. 34 Speciation 1. If 9% of the population has blue eyes, what percent of the population is hybrid for brown eyes? Homozygous for brown eyes? 2. Why are the peppered and charcoal moths an example of directional selection? 3. Provide an example of polymorphism.

10/15 Daily Catalyst Pg. 34 Speciation 1. If 9% of the population has blue eyes, what percent of the population is hybrid for brown eyes? Homozygous for brown eyes? 2. Why are the peppered and charcoal moths an example of directional selection? The allele frequency of the peppered coloring shifted to the alleles for charcoal coloring. 3. Provide an example of polymorphism. Is the presence of two or more distinct phenotype forms. Example: light and dark shell Each morph is adapted in a different area

10/15 Class Business Pg. 34 Speciation Evolution test on Tuesday, October 21st Evolution debate on Monday, October 20th Study guide due Tuesday, October 21st Review day on Friday Must bring questions! COME SEE ME FOR TUTORING LET ME KNOW WHEN YOU ARE COMING

Who did Frankenstein take to the dance? His “ghoul” friend!

10/15 Agenda Pg. 34 Speciation Daily Catalyst Class Business Hardy-Weinberg problem Heterozygote advantage Speciation notes Homework: Workbook 143-146 and STUDY

Hardy Weinberg Problem Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 40% of all butterflies are white. Given this simple information, which is something that is very likely to be on an exam, calculate the following: The percentage of butterflies in the population that are heterozygous. The frequency of homozygous dominant individuals.

Pg. 33 Heterozygote Advantage: Preserves multiple alleles in a population The hybrid form has greater reproductive success. We are talking about the genotypes (Bb) not phenotypes!

Pg. 33 Heterozygote Advantage: Sickle Cell Anemia People who are hybrid (Ss) do not suffer from sickle cell AND they are resistant to Malaria Homozygous dominant (SS) may die from Malaria Homozygous recessive (ss) suffer from sickle cell

Variation Natural Selection can alter the frequency of inherited traits in a population. Natural selection acts on the phenotypes You either got it or ya don’t!

Directional Selection One phenotype replaces another Rapid shifts in allelic frequencies ie: peppered moths in England

Stabilizing Selection Eliminates the extremes Favors the more common form ie: human birth weights

Disruptive Selection Favors the extremes Result in polymorphism May result in the formation of new species ie: light colored and dark colored mice are favored while intermediate colored mice are not favored.

Recap… Turn and talk Take 1 minute to discuss with a neighbor about microevolution and what can lead to changes in gene pools.

Macroevolution

Looks Can Be Deceiving! These meadowlarks look very similar yet they are not the same species. By contrast, these brittle stars look very different from one another, but they are the same species. One of the outcomes of evolution is the formation of new species. What is a species? Allow the students come up with a definition and debate its merit. Several definitions of macroevolution also exist depending on the textbook you use. Evolving complex structures such as an eye. Speciation Evolution of whole communities.

Definition of Species Key Point #1: Able to reproduce Key Point #1: Species: A group of interbreeding organisms that produce viable, fertile offspring in nature. Members of a species will interbreed with one another but not other organisms outside of the species. (At least most of the time!) Note the italics on “viable”! Hybrid animals exist which also makes the information in the second bullet need some qualifiers! Now is a good a time as any to see if students know about hybrids at all and/or can list any. This site has photos of the “Top Twenty” most popular animal hybrids: http://www.buzzfeed.com/toyota/the-20-coolest-hybrid-animals-3d8x A zebroid (zebra and equine) and donkra (donkey and zebra) are pictured. Hybrids will be revisited later as well.

Lions form groups or prides and live in the grasslands. Tigers and lions will interbreed in captivity, but they do not interbreed in nature. Lions form groups or prides and live in the grasslands. Tigers are more solitary and live in the forests. Tiglon are products of male tigers and female lions. Ligers are the opposite cross. These animals will interbreed with one another but on a limited basis. So are they the same species? No. How do we know? The offspring are not viable.

Macroevolution vs. Microevolution Key Point #2: Macroevolution is evolution on a scale of multiple gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast with microevolution, which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population.

What is speciation? Key Point #3: When a species is ___________ physically or reproductively from one another, the group of genes diverge from one another The two group will begin to evolve differently due to different environments (survival of the fittest is environment dependent) The two groups will evolve so differently that if brought back together, they would not interbreed again. A new species has been created =SPECIATION ISOLATED

Allopatric and sympatric speciation are two modes of speciation due to a type of ISOLATION

Allopatric vs. Sympatric Speciation Key Point #4: Allopatric speciation: caused by geographic isolation mountain ranges, canyons, rivers, lakes, glaciers, altitude or longitude. Key Point #5: Sympatric speciation: speciation occurs even though the two groups are still living in the same area.

Allopatric Speciation Graphic-Campbell An extrinsic is a property is one that is not dependent on the organism in question. It is an external factor.

Allopatric Speciation They become separate species, as evidenced by the fact they can no longer interbreed. If they can still interbreed, they are the same species. Islands produce some of the most profound examples of speciation due to geographic isolation.

Why does speciation occur after geographic isolation? The population that left the original group will have a different allelic make-up than the original species, thus experiencing the “founder effect”. The two groups will continue to experience different mutations. The two groups will now experience genetic drift and different selection pressures due to living in separate and perhaps different environments. Have students write down a possible answer before talking about the answer.

Sympatric speciation has no geographic constraint to interbreeding. Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that they occur together at least in some places.

Sympatric Speciation Sympatric Speciation occurs without geographic isolation, thus it occurs at a local level. There is something within the environment that keeps a single species separated into two or more distinct groups. The end result is that the two groups evolve into separate species. Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that they occur together at least in some places.

Sympatric Speciation Suppose that a certain species feeds on a particular host and only that host. Next, suppose a mutation occurs that allows it to feed upon a different host. Eventually, the species is divided into two groups that are separated from one another. Given enough time, speciation can occur. The species of treehoppers pictured above are host specific. The first lives on bittersweet while the second lives on butternut. Tree hopper ecology: Treehoppers pierce plant stems with their beaks, and feed upon sap. The immatures can frequently be found on herbaceous shrubs and grasses, whereas the adults more often frequent hardwood tree species. Excess sap becomes concentrated as honeydew, which often attracts ants. Some species have a well-developed ant mutualism, and these species are normally gregarious, as well, which attracts more ants. The ants provide protection from predators. Treehoppers mimic thorns to prevent predators from spotting them. Another example is the North American apple maggot fly (Rhagoletis pomenella) originally it lived in native hawthorn trees but about 200 years ago some of these flies colonized apple trees. Because apples mature more quickly than hawthorn fruit, natural selection favored those apple feeding flies. These two populations are classifies as subspecies but it is predicted in the future they will become separate species.

What is that “something” that separates the groups? Polyploidy Habitat isolation Behavioral isolation Temporal isolation Reproductive isolation

Sympatric Speciation: Polyploidy Key Point #6: Polyploidy: organisms with more than two sets of chromosomes. Occurs mainly in plants **Cannot interbreed with non polyploidy** Polyploidy may occur due to abnormal cell division Review the concept of nondisjunction of chromosomes during meiosis. True polyploidy rarely occurs in humans, although it occurs in some tissues (especially in the liver). Aneuploidy is more common. Polyploidy occurs in humans in the form of triploidy, with 69 chromosomes (sometimes called 69,XXX), and tetraploidy with 92 chromosomes (sometimes called 92,XXXX). Triploidy, usually due to polyspermy, occurs in about 2–3% of all human pregnancies and ~15% of miscarriages.[citation needed] The vast majority of triploid conceptions end as miscarriage and those that do survive to term typically die shortly after birth. In some cases survival past birth may occur longer if there is mixoploidy with both a diploid and a triploid cell population present.

Sympatric Speciation: Habitat Isolation Key Point #7: Two organisms live in the same area, but rarely encounter one another. Example: Two species on one genus of snake found in the same area. One lives in the water and the other lives on land.

Sympatric Speciation: Behavioral Isolation Key Point #8: Mating behavior For example: small saltwater fish males change in color and develop a red underbelly. The male builds a nest and court the female with a dance. If at any time this ritual fails, then no mating occurs and no offspring is produced.

Sympatric Speciation: Temporal Isolation Key Point #9: Isolated by time For example: a flowering plants colonizes a region with areas that are warm and sunny and areas that are cool and shady. Flowers in the warm region become sexually mature sooner than the cooler areas. This separates the flowers.

Sympatric Speciation: Reproductive Isolation Key Point #10: Closely related species unable to mate For example: difference in flower shape may prevent pollination and the difference in the structure of genitalia may prevent insemination.

Sympatric Speciation: Reproductive Isolation Prezygotic barriers: Barrier to mating. For example: small male dog and large female dog Postzygotic barriers: Once mating has occurred, fertile offspring cannot be produced. For example: horse and donkey produce a mule

Patterns of Evolution: Reading Patterns of Evolution: Divergent Evolution Convergent Evolution Parallel Evolution Coevolution Adaptive radiation