Warm up: Organize folder and pick papers up at front ßPage 1-2: Table of Contents ßPage 3-6: Warm up ßPage 7: Gallery Walk Review (what we did outside of classroom) ßPage 8: Non-Mendelian Notes ßPage 9: Mitosis Review Notes ßPage 10: Mitosis vs. Meiosis Worksheet

Notes: Evolution & Natural Selection

Evolution ßWhat scientific explanation can account for the diversity of life? ßThe answer is a collection of scientific facts, observations, and hypotheses known as evolutionary theory. ß Evolution, or the change over time, is the process by which modern organisms have descended from ancient organisms.

Charles Darwin Charles Darwin is the individual that has contributed more to our understanding of evolution than anyone. His father was a wealthy doctor and wanted Charles to become a doctor. At age 16, he went to Medical School. In 1827, his father sent him to become a priest. In 1831, a friend asked him to go on a ocean trip as an unpaid naturalist on the HMS Beagle.

Lamark was a French naturalist who… ßClaimed that organisms tend to be complex and perfect and are therefore unchanging. ßUse and disuse- Lamark thought that animals could change their bodies by using them in new ways. Example: animals could use front limbs as wings and develop flight. ßInheritance of acquired traits- Lamark though that all changes could be inherited. For example, if you life weights, your children would inherit your muscles. ßLamark’s ideas are not scientifically accepted today!

Darwin’s Voyage on the HMS Beagle The purpose of the trip was to draw accurate maps of the region. Darwin was to collect specimens and document the plant and animal life.

Darwin’s original beliefs Divine creation - each species was created by God, unchanging and existing as it was originally created. On the voyage Charles made numerous observations & collected evidence that led him to propose a revolutionary hypothesis about the way life changes

Darwin’s Finches In the Galapogos Islands, Darwin observed finches showed convincing evidence that species evolve.

 Darwin was struck by the fact that the animals of the Galapagos Islands resembled those of the nearby coast of South America.  He saw patterns of diversity & was intrigued by the fact that so many plants and animals seemed remarkably well suited to whatever environment they inhabited.  Darwin hypothesized that ancestors of the Galapagos Islands must have migrated to the island and changed after they arrived.  That hypothesis, now supported by a huge body of evidence, has become the Theory of Evolution.

Darwin published his book in 1844: On the Origin of Species by Means of Natural Selection. In this book Darwin developed a scientific hypothesis to explain how evolution occurs: The Theory of Natural Selection. Natural Selection – process by which individuals that are better suited to their environment survive and reproduce more successfully (survival of the fittest)

Darwin’s Theory of Natural Selection 1.There is variation within any species 2.All organisms tend to over-reproduce 3.There is a struggle for survival 4.The fittest survive 5.The environment determines who is the fittest

1. Variation exists within every population 1. Ladybugs have different spots

2. Zebras all have different stripes 1. Variation exists within every population

2. All species tend to produce more offspring than they can SUPPORT 3. Frog eggs 1. Turtle eggs 2. Insect eggs 4. Baby mice

3. There is a Struggle for Survival 1.To eat 2.To drink 3.Territory 4.To mate

4. The fittest will survive

1. Weak or strong woman? 2. Healthy or sick horse?

5. Nature (the environment) will determine which organism is the fittest to Survive 1. long neck giraffes survive over short neck giraffes.

Evidence of Natural Selection in our lifetime The Peppered Moth in England Before the industrial revolution After the industrial revolution

Explanation for the peppered moth There was variation in the moth population to begin with, some were black and some were white. This variation was due to random mutations.

Before the industrial revolution, the bark of the tree bark was white in color. The white moths then were easily camouflaged, survived, and reproduced. Black moths were rare.

After the industrial revolution, the trees became covered in soot/pollution from all of the factories and the trees turned black. Now the black moth were easily camouflaged, survived, and reproduced. White moths were rare.

How does the peppered moth illustrate natural selection? There was variation in the population to begin with (some white, some black). Moths tend to over-reproduce. Therefore there is a struggle for survival. The fittest (those that were camouflaged the best) survived. The environment determined which moths were the most fit.

Natural Selection may lead to Speciation Speciation - the evolution of a new species Natural Selection produces changes in POPULATIONS over time: NOT INDIVIDUALS.

The process of speciation ßGeographic Isolation - when two populations become isolated by a geographic barrier. Geographic Isolation

ßReproductive Isolation - Sometimes when populations have been separated for a long, long time, they become so different that they can no longer breed and produced fertile offspring. Same species now, but may become two different ones.

1. Horse and Donkey = Mule Mule is infertile (can’t have babies) mule horse donkey

Lion and Tiger = Liger Liger is often infertile (there have been successful breedings)

2. The Kaibab and Abert Squirrels Became reproductively isolated by huge mountains

3. Wood and Leopard Frogs Leopard frogsWood frogs Seem to be the same species, but they breed at different times of the year.

ßSpeciation - When two populations become so different that they can no longer breed and produce fertile offspring. They are then considered two separate species.