Question | Answer |
What is the definition of evolution? | Change over time |
How old is the earth predicted to be? | 4.6 billion years ago |
The evidence suggests that life first began how long ago | 3.8 billion years ago |
What were the first living organisms on the planet? | Prokaryotes |
How long ago did multicellular life appear? | 1.2 billion years ago |
When did fungi and plants begin to colonize the land? | 500 million years ago |
When did the earliest pre-human ancestors appear? | 6 to 7 million years ago |
When did humans (homo sapiens) first appear? | 195,000 years ago |
How many times have all the land masses on the earth come together to form one giant supercontinent? | 7 times |
Eras in time are separated by what event? | A mass extinction |
What process causes the earth to constantly change form? | Continental Drift / Plate Techtonics |
How long ago did Pangea break apart? | 200 million years ago |
What was the largest mass extinction on record? How many species died off? | The Permian Mass Extinction. 86% of all species. 96% of marine animals. 70% of terrestrial life. |
How was the early atmosphere on earth different from the atmosphere we have now? | The atmosphere had no O2 and was thick with water vapor & various compounds were released. |
Who were the first two scientists to suggest that organic molecules could have formed during the early stages of the earth? | A.I. Oparin & J.B. Haldane |
Explain the Miller-Urey experiment and what it tells us about the possibilities of how life began. | They caused an enclosed system that represented the atmosphere & Sea. Electricity which represented lightning. Condensed represented rain. Amino Acids were in the water vapor. This gave us some type of idea how life was created. |
What are the five main pieces of evidence we use to support evolution? | 1) Biogeography
2) Embryology
3) Fossil Record
4) Comparative Anatomy
5) Molecular Biology |
How do we use Biogeography to show how organisms are related? | Look at where organisms are located & their adaptations in geographic distribution. |
How do we use Embryology to show how organisms are related? | Comparison of early stages of development among different organisms |
How do we use Fossil Record to show how organisms are related? | Shows past organisms & where they were alive / fossils are compared to see evolutionary change |
How do we use Comparative Anatomy to show how organisms are related? | Comparison of body structures in different species |
How do we use Molecular Biology to show how organisms are related? | Reveal evolutionary relationships comparing DNA & AA sequences between different organisms |
Why is the fossil record an incomplete story? | Only 1% of all organisms are fossilized |
How many of the organisms that have ever lived have gone extinct? | 99% |
About how many of the extinct organisms have become fossilized? | 1% |
What are the types of fossils? | 1) Petrified Fossil
2) Cast
3) Mold
4) Imprints |
Describe a Petrified Fossil. | Organic material is replaced with minerals |
Describe a Cast. | Mold fills with material, 3D model of the mold. |
Describe a Mold. | Deeper pattern in rock, Hard tissue |
Describe a Imprint. | Shallow pattern in rock, Soft tissue |
What method do we use to determine the age of fossils and the earth? | Radiometric Dating (Carbon Dating) |
How can we use the strata layers to determine the age of fossils relative age of fossils? | The further down the strata the older it is. |
Explain why an individual organism cannot go through the process of evolution. | An individual organism cannot go through evolution alone because you cannot change your DNA. Genes have to be passed on. |
What does go through evolution? How does this occur? | A species / population. The unfit for the environment die off and good traits are passed on. |
What is a homologous structure? Give an example. | Structures that are similar but have different functions. Human Arm V. Whale Arm. |
What is an analogous structure? Give an example. | Structures that have the same function but evolved evolved separately. Bat V. Bird. |
What is a vestigial structure? Give an example. | Remnants of features that served important functions in an organism's ancestors. In humans an Appendix, Tailbone, and Wisdom Teeth. In a Whale the Hip Bone. |
What is speciation? | New species arise from old species. |
What was the name of the ship Darwin was on? | H.M.S Beagle |
How long did Darwin sail around the world collecting his evidence? | Five years |
On what island chain did Darwin make many of his major discoveries? | Galapagos Islands |
What were the main organisms and the traits that he observed? | Finches |
What did Lamarck believe about evolution? | Lamarck believed that if you use something then use pass that trait on, but if you don't use that trait then you don't pass it on. |
What mechanism did Darwin suggest as the driving factor of evolution? | Natural Selection |
Describe how natural selection works. | Populations evolve, amplify or diminish heritable traits. If the environment changes them the animal with the best traits live & the bad traits die. Some traits are better at surviving. |
What must a population have in order to experience evolution or natural selection? | Variation |
Explain evolution is a never ending process that never leads to perfection. | Evolution is a change because of the environment. We will have to keep changing with the environment. |
Why might an organism be the most "fit" today, but in five years, those same traits may be considered "unfit"? | The environment changes & we might not have the trait needed anymore. |
What is microevolution? | A small change in the gene pool |
Does natural selection / evolution act upon the genotype or the phenotype of an individual? | Phenotype |
Explain why evolution is an "indirect force". | |
Explain how washing your hands can cause evolution. | There becomes less variation in bacteria because you killed the bacteria that was not resistant so the ones that are resistant reproduced. |
What is a gene pool? | Total collection of genes in a population at any one time that may be passed on to the next generation. |
What is allele frequency? | How often a certain allele is in the gene pool |
How does mutation affect the genes of a population? | Introduces new genes to a population. |
How does sexual reproduction help to increase variation within a population? | Makes sure genes get randomly passed on. |
How does Hardy-Weinberg tell if evolution is occurring? | Hardy-Weinberg can show a change in the relative frequencies of alleles |
What are the five main causes for genetic change? | 1) Natural Selection
2) Genetic Drift
3) Gene Flow
4) Mutation
5) Sexual Selection (Non-Random Mating) |
How does non-random mating affect the genetics of a population? | Individuals choose certain characteristics to pass on & then there is less variation between individuals. Could lead to a weaker population. |
What is gene flow? | Movement of individuals or gametes / spores between population & can alter allele frequencies in a population (migration). |
What is genetic drift? How do finches show this? | Change in the gene pool of a population due to chance (random). Ex: earthquake. The finches show the founder effect. |
What is the bottleneck effect? | A loss of genetic diversity when a population is greatly reduced due to natural disasters. |
What is the founder effect? | When a few individuals colonize a new habitat. Start with limited genes in the population. |
What is relative fitness? | The contribution it makes to the gene pool of the next generation relative to the contribution of other individuals . Your ability to survive & reproduce. |
What is stabilizing selection? | Favors intermediate phenotypes, acting against extreme phenotypes. Variation is less. Extremes go away. |
What is directional selection? | Acts against individuals at one of the phenotypic extremes. |
What is disruptive selection? | Favors individuals at both extremes of the phenotypic range. Leads to new species. |
What is sexual selection? | When you choose your mate based on phenotype. |
What is a species according to the biological species concept? | A group of populations who live in the same place, interbreed in nature, and produce fertile offspring. |
What definition would we use to determine what species a fossil is? Why can't we use the biological species concept for this? | Morphological species concept classifies organisms based on physical appearance. |
What is reproductive isolation? | Prevents members of different species from mating with each other. Prevents flow between species & maintains separate species. |
What are reproductive barriers? | Anything that causes reproductive isolation. |
What is a prezygotic barrier? What are the five types of this? | Prezygotic barriers prevent mating or fertilization between species. 1) Habitat Isolation 2) Temporal Isolation 3) Behavioral Isolation 4) Mechanical Isolation 5) Gametic Isolation 6) Geographically Separated. |
What is a postzygotic barrier? What are the three types of this? | Prevents proper development. 1) Reduced Hybrid Viability 2) Reduced Hybrid Fertility 3) Hybrid Breakdown |
What is allopatric speciation? | Population of the same species are geographically separated, Isolating their gene pools. Caused bulk of different organisms |
What is sympatric speciation? | Occurs when a new species arises within the same geographic areas as a parent species. Become unable to reproduce |
What is adaptive radiation? How do the finches exhibit this? | The evolution of many diverse species from a common ancestor. The finches are 14 different species but all came from 1 animal |
What is gradualism? When does this type of speciation occur? | Very slow constant change. When environment changes slowly |
What is punctuated equilibrium? When does this type of speciation occur? | Species change most as they arrive from an ancestral species & them experience relatively little changes for the rest of their existence. Rapid change then stay the same for a long, earth changes rapidly. |
Explain whether natural selection / evolution is a planned process or a random process. | Random you can't predict what the environment will look like. |