THE HISTORY OF THE THEORY. Darwin presented that happens and offered an of how it happens. Theory a broad that has been and

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1 Evolution Notes THE HISTORY OF THE THEORY Why is the evolutionary theory associated with Charles Darwin? Darwin presented that happens and offered an of how it happens. o Evolution the process by which Theory a broad that has been and o Keeps and as more evidence is of Darwin s theory remains supported to this day. How did Darwin come up with the theory of evolution by natural selection? Darwin wanted to understand the on Earth. o Biodiversity the of things Darwin was intrigued that so many and seemed so well to their. Darwin was also impressed by the ways that organisms and. Organisms that lived in similar in different parts of the were very. The Voyage of the HMS Beagle As the on the ship, Darwin collected and specimen and made thousands of about the organisms and their. The Galápagos Islands volcanic islands in the Ocean near Ecuador Darwin s Fossils Some fossils looked to species living today, and some looked like anything he had ever seen. Biodiversity on the Galapagos Islands Although the Galapagos Islands are very close together, they have very. The plants and animals of each were to that specific. Tortoises The shape of tortoise changed depending on the type of available on the island. Finches Darwin noticed the and of the were different depending on the type of available for the finch to.

2 Marine Iguanas Reptiles that underwater for but live on land. Artificial Selection/Selective Breeding Darwin realized that exists in every of organisms. Breeders were taking of the variation in within a. o Select with traits to produce with those traits. Darwin called this process because were selecting. (AKA ) o Artificial selection - choosing for organisms to produce traits in. Darwin realized that were driving the of many plant and animal. Other Scientists with Theories Jean Baptiste Lamarck ( ) o Organisms over. o All species are the of the that came them. o All organisms are trying to be more and more. o Traits pass to based on and ( it or it). o Offspring can inherit traits. Thomas Malthus ( ) Observed that the population was increasing than the supply. Humans would eventually from,, or. o applied this idea to all.» Populations produce more than its can, therefore, many will. Georges Curvier Argued that in rock layers showed in throughout and many species from the differed from those in the. James Hutton and Charles Lyell processes (like ) work and. o Darwin concluded that the Earth is old enough for. In, Darwin received a letter from Alfred. His essay outlined Darwin s idea of by natural selection. Darwin published his book, On the of by means of Natural Selection in. Darwin s book explained the of evolution and provided that evolution has been taking place for of years and to happen today.

3 EVOLUTION BY NATURAL SELECTION What is the ultimate goal for all organisms? Struggle for o Members of a species regularly to obtain, living space,, etc. o A key factor in the is how well an organism is to its. Fitness - the of an organism to AND o Fitness is the result of. Adaptation any that increase an organism s of or. o Camouflage an adaptation that allows organisms to with the to become less visible to or. o Mimicry an adaptation where one another Natural selection adapted individuals and reproduce more ( fitness) adapted individuals have less chance of and reproduction ( fitness) o Only certain in a population will produce o The traits in the causing the entire population to evolve not the. o An cannot make itself to the environment; it s all in the. Evolution is a process of. Descent with Modification each species has descended, with, from other over. Evidence for Darwin s Theory The Fossil Record all the of that lived in the o Comparing and organisms reveals a of gradual from the to. Biogeography the study of the of organisms around the o Scientists have found the of in Earth s past help explain patterns in the and of both living and fossil. Anatomy comparing the structures of different o Homologous structures structures that have develop from the in the (may not have the same )» Homologous structures result from

4 o Analogous structures that evolve in groups because of similar or due to evolution.» Example,, and all have that are used to but each evolved. The of the wings and the that produce them are. o Vestigial Structures body parts that do not seem to play a in an organism s life (evolutionary )» Example the human has no apparent function while rats and other rodents have an appendix that aids in» Example and have a pelvis and femur Embryology comparing the development of organisms to look for similar and Biochemistry comparing the of different Strengths and Weaknesses of Darwin s Theory Strengths (1) Supported by a lot of, (2) and testable, and (3) still stands Weakness Darwin knew very little about because was just starting to count (Mendel s work was not published until ). MICROEVOLUTION What is Microevolution? in the Genetic is studied in. o Population a group of in the same in a given that. Because organisms in a population, they share a. o Gene pool all the in a An individual that to reproduce its from the gene pool. Causes of Microevolution Sexual Selection a based his/her o Examples o Random selection of mates leads to numbers of in the which genetic variation. o Choosy mates leads to a set of in the which genetic variation.

5 Gene flow - the of into or out of a gene pool which genetic variation. o Caused by the of the Genetic drift the in everyday life survival and reproduction and genetic variation. o VERY POWERFUL in populations. Mutations can add new to the which genetic variation. o That allele may be more or less to the particular organism. Natural Selection o Organisms that are better to the are more likely to o AND, those traits to the which drives the of the. o Over time, the genes are of the. o Natural selection requires in the. o Natural selection acts on (physical characteristics). Types of Natural Selection Stabilizing selection is favored and are eliminated which is most common in environments. o Example Directional Selection one is favored and the other is selected o Example Disruptive Selection both are favored and the is eliminated o Often leads to o Example - Hardy-Weinberg Principle Populations will not without acting on them causing them to.

6 MACROEVOLUTION = Speciation a new What is a species? a group of individuals that can and produce offspring Every population s is ; therefore, every population will. How does Macroevolution Happen? Reproductive Isolation a state in which two can no longer to produce fertile o May be caused by or Patterns of Evolution Adaptive Radiation one species into several over time due to natural selection and to the environment Coevolution organisms that live in close in a community may evolve. o Example Gradualism changes over a period of time causing changes like forming a species o Supported by the Punctuated Equilibrium a pattern of long, periods interrupted by periods of rapid o May be caused by to new habitats, geographic, or of a competing species Do all species change? Some species remain in with very little for long periods of Extinction o Example horseshoe crab (we have fossils 445 million years old) and velvet worms (date back 400 million years) What happens if a species cannot adapt to changes? o If all the organisms in a species or simply fail to, they become. The shows that many species have gone. o More than % of all species that have ever lived are already. Most causes of are the result of.