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Evolution

QuestionAnswer
Who is the Father of Evolution? Charles Darwin.
Darwin was the first to do what? Describe the concepts of natural selection and artificial selection.
What did Darwin publish? The Origin of Species by Means of Natural Selection. This was published in 1859.
What are the three basic observations of natural selection? Organisms in the same species have variations, all organisms produce many offspring (more than enough to replace themselves), and populations generally remain about the same size.
What is natural selection? The process by which traits or alleles become more or less frequent in a population, depending on the advantage or disadvantage they have on the survival and reproduction of the organism.
True or False: Natural selection is continually tweaking biological structures. True
What is selective breeding? Taking individual plants or animals with desired traits and crossing them. This would usually take place over a number of generations until a new breed was produced.
What is artificial selection? Selective breeding of plants and animals by humans.
What is biogeography? The study of the distribution of organisms, species, ecosystems, and biomes around the world and can be linked to the evolving geologic pattern of the Earth.
What are the factors that affect the distribution of organisms and biological communities? Habitat area, climate and soil composition, longitude, latitude, and elevation, and the geological history of a region.
What does the term adaptation refer to? Scientists use the word adaptation to describe the physical and behavioral changes that enable successful reproduction.
True or False: Diversity within a species commonly arises when populations of a species are together in some way. FALSE: Diversity within a species commonly arises when populations of a species are SEPARATED in some way.
What is used as evidence for evolution? The fossil record. The fossil record contains data that indicates that groups of organisms appeared in a sequential nature.
What is homology? The similarity in anatomical features resulting from common ancestry.
True or False: Not all structures that look alike or perform the same function are homologous. True. Similar structures may evolve independently in different groups of unrelated organisms.
What is convergent evolution? A process by which two unrelated organisms will share similar features due to the similar pressures of natural selection
What is developmental homology? A common embryonic trait in different organisms. The presence of these common embryonic traits suggests that these different species share a long-ago common ancestor.
True or False: Molecular (DNA or protein/amino acid) sequencing can be used to analyze and evaluate the molecules of life in a group of organisms. True!
What are molecular clocks? Molecular clocks are techniques that use genetic mutation rates to determine historical time when divergence of species occurs.
There are many gaps in the fossil record and many sudden appearances. What kinds of questions help to explain this?. Does a sudden appearance suggest that a species or body form suddenly appeared? Was it simply not preserved in the fossil record previously? Has it not yet been discovered?
Explain how the Cambrian explosion came about? The sudden disappearance of many life forms in the fossil record just before the Cambrian suggests that a mass extinction occurred. For those species that survived a mass extinction, new ecological niches became available.
What might genetic variation look like? Physiological, structural, or behavioral.
How does genetic variation arise? Mutation, recombination, and gene flow.
True or False: Evolution acts on individuals, not populations. FALSE! An important aspect of evolution is that it acts on populations, not individuals. Although natural selection acts on individuals, the changes caused by it affect the allele frequency of the entire population.
What is sexual selection? A type of natural selection where selective pressures result from the selection of mates with particular characteristics.
Explain gene flow. Gene flow describes the movement of alleles into and out of a gene pool.
Explain genetic drift. The number of individuals carrying particular alleles in a population at equilibrium fluctuates randomly around a mean.
True or False: In smaller populations, the gene frequency may fluctuate more widely. In a small population, it is possible that, through random genetic drift, a gene may be lost altogether. True!
What are forms of genetic drift? Founder and bottleneck effects.
Explain a bottleneck effect. A limited variety of alleles in a population due to a dramatic decrease in population size. The bottleneck effect can greatly reduce the genetic variation of a population.
What is the founder effect? The loss of genetic diversity that occurs when a small number of individuals from a large population of a species establish a new population
What is directional selection? A type of natural selection where selective pressures on a species favors one phenotype to be selected. Since individuals having this trait are more likely to survive and reproduce, the trait’s allele frequency increases in the population.
When does diversifying/disruptive selection occur? Disruptive or diversifying selection occurs when extreme phenotypes are favored and selected instead of those with average or intermediate phenotypes.
What is stabilizing selection? A type of natural selection where selective pressures favor the middle of the phenotypic range of traits. It reduces diversity in a species.
What is coevolution? The evolution of two different but complimentary characteristics in organisms that interact with each other.
What is the Hardy-Weinberg equilibrium ? The Hardy-Weinberg equilibrium is a principle that can be used as a baseline against which changes in allele frequencies among a population can be measured.
What does the The Hardy-Weinberg equilibrium state? The principle states that, in the absence of disturbing factors, different genotype frequencies in a population will reach an equilibrium and will remain stable over generations. Evolution should be expected all of the time.
What are the conditions of the Hardy-Weinberg equilibrium? no mutation, no migration into or out of the population, infinitely large population size, no natural selection, no sexual selection (random mating), organisms are diploid and allele frequencies are equal in both sexes
Can the Hardy-Weinberg equilibrium be met in nature? No.
Know the Hardy-Weinberg equation. (frequency of B)^2+2(frequency of B)(frequency of b)+(frequency of b)^2= 1
What is speciation? The formation of a new species. Once populations can no longer reproduce with each other, speciation can occur.
What is sympatric speciation? A divergence based on behavioral, ecological, or genetic reasons. This happens when two or more descendants arise from a single ancestral species and all of them are located in the same geographical region.
What is parapatric speciation? A new species evolves due to changes in nonrandom mating. This happens by divergence of species but only a partial separation of their geographic location.
What is allopatric speciation? the evolution of a population into a new species when the population is separated from other members of the original species by a geographic barrier.
The punctuated equilibrium may be used to explain what? The periods of time in which equilibrium is interrupted or punctuated with short bursts of speciation. Punctuated equilibrium is a useful model for understanding how the fossil record forms.
What is macroevolution? Macroevolution events are major evolutionary events that show transitions over time from one species, genus, family, or class to the next, as exemplified by fish descending from an invertebrate and whales descending from a land mammal.
What is microevolution? Microevolution refers to changes on a small scale, such as changes in gene frequency within a population working as natural selection or artificial selection.
What is one way to know that speciation has occurred? The two populations cannot reproduce
A population has an allele R with a frequency of 40 percent. What is the frequency of the genotype RR? 16%
The evidence showing that the chimpanzee genetic code is 96% the same as the human genetic code is an example of ________. Molecular sequencing
What would represent a homologous structure? cat paw and a human hand
One weakness of the fossil record is? soft tissues are generally not preserved in fossils
Fossils show that ancestors of the giraffe had shorter necks than the modern giraffe. The evolution of the modern giraffe may be an example of ________. Directional selection
The frequency for the dominant allele in a population is 0.75. What must the frequency of the recessive allele be? .25
Comparative morphology is evidence for evolution because? related organisms have homologous structures
The type of speciation in which a new species develops because of geographical isolation is Allopatric Speciation
Created by: JustEmma
 

 



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