Change Over Time
and the Evolution of Living Things
Fundamental Concepts and Skills / Citation1. The Fossil Record
a) A fossil is any evidence of an organism that lived long ago.
b) The approximate ages of fossils can be determined by how deeply they are buried in sediments or by Radiometric dating using decay of atoms to determine exact age.
c) A history of life on earth can be reconstructed by dating fossils and examining layers of sediments on the earth’s crust—this is known as the fossil record.
d) Fossils help scientists to understand the order in which changes in living things occurred on earth this is called the fossil record. It helps reconstruct evolutionary history.
e) When no living organisms of a particular species are living it is considered extinct.
i. There are a great variety of extinct species in the fossil record that provides clues to the conditions on the earth as well as how changes occur over time. / LS 13 b
p.153
Online Text 153-157
2. Structural Evidence of Evolutionary History
a) Organisms that share a common bone structure
a. Each structure is modified for the different functions of the organism. (wings)
b) Homologous structures are structures shared by different species that indicate a common ancestor (whale pelvis).
c) Vestigial structures are organs/bones in organisms that are no longer used as they were in the past.
i. Tonsils, tail bone in humans, pelvis in the whale / LS 13 a
p. 153-157
Online Text 170-183
3. Natural Selection—changes in populations over time (4 Parts of Natural Selection)
a) All populations produce more offspring than the environment can support.
b) This leads to a struggle to survive—only a fraction of those born make it to adulthood.
c) There is great genetic variation (genetic variety, differences) among individuals in a population due to mutations.
d) After the favorable mutation is passed on to offspring by surviving parents, it eventually becomes an adaptation.
I. An adaptation is anything (structure or behavior) that an organism has that allows it to survive to reproduce in its environment.
e) Those individuals best fit (with the most useful adaptations) to the environment where they live survive and successfully reproduce more offspring that those without useful adaptations.
I. Successful reproduction is the key to natural selection—there’s no advantage for future populations in having a useful adaptation if they are not passed to offspring.
f) The unequal ability of individuals to survive and reproduce leads to gradual change in populations’ generation after generation.
g) Real life examples of natural selection in action include pesticide resistance in insects and antibiotic resistance in bacteria. (Mrs. Phipps Leg!!)
h) Natural Selection can only work through variation already present in DNA
i) Over time, two population (separated for whatever reason) can evolve so differently they can no longer interbreed. (This is known as speciation) / LS 13 a, c
p. 150-151, 162
Online Text 170-183; 186-189
p.164-167
4. Passing of Traits, Genetics, and Evolution
a) Remember: Only traits present in parent DNA can be passed to offspring—evolution ONLY act on traits which are inherited.
b) Mutations are the ultimate source of genetic variation.
I. Mutations may result in a favorable change which leads to adaptation.
II. Mutations may result in no change in survival.
III. Mutations may result in an unfavorable change which may negatively impact survival.
c) If a species does not include traits that enable it to survive in its environment or to survive changes in the environment, then the species may become extinct. / LS 13 a
p.164-165
5. The history of evolutionary biology
a) Lyell- One of the first scientists to recognize that organisms change over time. He had the right idea—just not HOW it happens.
b) Malthus- discovered that population size could affect and be affected by the amount of resources available.
c) Darwin- developed the evolutionary theory by natural selection. He published his book on the topic called The Origin of Species by Means of Natural Selection in 1859, years after his discovery was completed.
I. Darwin’s finches- the size and shape of the finch’s beak evolved because the type of food available and the need for all finches to have food.
d) Wallace- also developed his own concept of evolution by natural selection similar to Darwin’s at the same time as Darwin. / LS14:a,b,c
Online Text book 162-169
Green Text Book159-163
6. Classification- the arrangement of organisms into orderly groups based on structural similarities and evolutionary history.
a) Binomial Nomenclature- the two name system for giving organisms a scientific name.
a. The scientific first name is the genus and is the first letter of the genus is always capitalized.
b. The scientific last name is the species and the first letter is always lower case.
c. Both the names are underlined or italicized.
b) The 6 Kingdoms
a. Archaebacteria- The most ancient living things on Earth—prokaryotic bacteria that live in extreme environments/conditions
i. Hot Springs, Volcanoes, Arctic Ice, etc.
b. Eubacteria- prokaryotic bacteria that do not live in extreme conditions like E. coli.
c. Protists- eukaryotic unicellular, or simple multicellular organisms with a variety of ways to survive. (amoebas, algae, seaweed)
d. Fungi- eukaryotic, mostly multicellular organisms (mushrooms, molds, and the disease athlete’s foot)
e. Plants- eukaryotic multicellular organisms that use photosynthesis to produce food. (maple trees, daises, grasses)
f. Animals- eukaryotic multicellular organisms (insects, sponges, crabs, and bats)
c) Dichotomous Key- a guide that is used to identify and classify unknown organisms
d) Carolus Linnaeus- a botanist known as the father of taxonomy. His system for naming, ranking, and classifying organisms is still in wide use today. / LS5:a
Green Text Book 200-218
Online Text 197-231
Whale Evolutionary and Fossil Record: Organization of Living Things and Evolutionary History: