BIO TEST
Each of the following is an example of stabilizing, disruptive, or directional selection. Choose the correct term for each example, explain why it fits that category and sketch the appropriate graph. The rocks at the bottom of a stream are either black or white. Snails that live on these rocks are a range of color from solid black to gray to solid white. A local freshwater fish loves to munch on these snails, but it cannot see the solid black or solid white snails when the snails are on matching rocks. Grey does not blend into either rock color and is much easier to see
disruptive
theory of evolution
explains the process by which organisms change over time as a result of changes in heritable, physical, or behavioral traits. Changes that allow an organism to better adapt to its environment will help it survive and have more offspring
One thing that's necessary for natural selection to occur is overproduction. An excess of organisms in a population leads to _________ between members of the same species causing a struggle to survive. This struggle is necessary because it allows the better adapted organisms to reproduce more often.
competition
charles darwin
developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through descent from common ancestors. "evolution by natural selection"
Each of the following is an example of stabilizing, disruptive, or directional selection. Choose the correct term for each example, explain why it fits that category and sketch the appropriate graph. Larger squirrels can carry larger acorns to their burrows, and they outcompete smaller squirrels when acorn supplies are limited.
directional
comparative biochemistry
involves the comparison of DNA, proteins, and chromosomes across different species, Similarities in the comparison are used as evidence in support of evolution
What are the six pieces of evidence that support evolution?
paleontology genetics embryology homologous analagous vestigial_
WHICH TYPE OF EVIDENCE Bird and butterfly wings have same function but different structures
Analogous Structures
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Hummingbirds have a beak just the right length to reach the nectar in a cardinal flower and as they feed their foreheads bump into the pollen structure. Cardinal flowers are red which hummingbirds can see but bees can't, and their pollen structure is at just the right height for the hummingbird to pick up pollen as it feeds.
COEVOLUTION
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Ostriches and giraffes are both native to the savannahs of Africa. They share the same characteristic of a very long neck.
CONVERGENT EVOLUTON
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Whales, sharks, and penguins all have streamlined bodies end appendages for moving in water even though they belong in different classes of animal classes (mammals, birds, fish)
CONVERGENT EVOLUTON
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Darwin's finches are all different but appear to have a common ancestor from the mainland.
DIVERGENT EVOLUTION
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Ostriches are native to the savannahs of Africa, while penguins live in the polar regions. Although ostriches and penguins are closely-related, they look very different.
DIVERGENT EVOLUTION
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION The Galápagos finches evolved through natural selection from a common ancestor into a wide variety of different looking species with different kinds of beaks
DIVERGENT EVOLUTION
Use the cladogram ON STUDY GUIDE to answer the following questions: What is the characteristic that is common to all organisms on the cladogram?
Developed from a blastula
Darwin supported his Descent with Modification theory with evidence from the Galapagos Islands. One of the main types of organisms he studied were the Galapagos Finches. Describe what Darwin found AND his explanation for the differences he found.
Different species of finches with different beaks- finches evolved from a common ancestor and adapted to different food sources.
What type of evolution did Darwin's findings support?
Divergent
WHICH TYPE OF EVIDENCE In the earliest stages of development, a tail and gill slits can be seen in fish, birds, rabbits, and mammals.
Embryology
What is the relationship between evolution & natural selection?
Evolution- Organisms change (frequency of allele) over time to have traits (driven by mutations and genetic recombinations) that are most beneficial for survival in their environment. Natural Selection- "nature" (environment) selects for the fitter/stronger traits.
According to Darwin, what makes an organism more "fit" than another?
Fitness, according to Darwin, is having traits that allow for survival (and reproduction) in one's environment.
WHICH TYPE OF EVIDENCE DNA and RNA comparisons
Genetics (Comparative Biochemistry)
Use the phylogenetic tree ON STUDY GUIDE to answer the following questions: Which two organisms shown would be found to have the most similar DNA?
Gray wolf/Dog- most recent branch
WHICH TYPE OF EVIDENCE Examples of forelimbs of bats, penguins, lizards, and monkeys
Homologous Structures
When trying to determine the evolutionary relationship between two species, would a biologist concentrate on homologous or analogous features? WHY??
Homologous- same structure, different function-indicates common ancestry
Use the cladogram ON STUDY GUIDE to answer the following questions: What organism(s) do not have a back bone or are considered invertebrates?
Insects
Using the giraffe neck example, explain how the views of Lamarck differed from Darwin's views.
Lamarck- "acquired characteristics"- stretched necks to reach food - passed onto offspring Darwin- "descent with modification"- giraffes with longer necks survived, reproduced, and passed on their genes
The other thing that's necessary for natural selection to occur is genetic variation amongst organisms because if they were all the same, natural selection would have nothing to "work" on. Describe the major ways genetic variation comes about.
Meiosis - crossing over / Sexual reproduction
If an organism has a structure that has been determined to be vestigial, what might a biologist think about the animal's evolutionary history?
Might infer that the organism once used this structure- ancestors most likely used this structure
Summarize the four principles by which Darwin based his ideas of evolution on. (You might want to go back to the Crash course video sheet on Natural Selection and your notes packet)
Organisms within a species have variations in phenotypes Organisms have more offspring than can survive Organisms with favorable traits survive Variations are heritable (can be passed on)
Match the type of Evolution with its description. You can use terms more than once!A. COEVOLUTION B. DIVERGENT EVOLUTION C. CONVERGENT EVOLUTON D. PARALLEL EVOLUTION Organisms with a common ancestor have been separated for a very, VERY long period of time (by Pangea splitting for example). Despite being separated, they have evolved into organisms with similar features
PARALLEL EVOLUTION
Use the cladogram ON STUDY GUIDE to answer the following questions: What organisms have hair?
Prosimians, humans
Use the phylogenetic tree ON STUDY GUIDE to answer the following questions: What do the branches in the tree represent?
Split from a common ancestor- relatedness
WHICH TYPE OF EVIDENCE A body structure reduced in function but may have been used in an ancestor
Vestigial Structures
WHICH TYPE OF EVIDENCE The forelimbs of flightless birds
Vestigial Structures
WHICH TYPE OF EVIDENCE A modified structure seen among different groups of descendants.
Vestigial Structures Paleontology
vestigal structures
a feature of an organism that is a remnant of a structure that served a function in the organism's ancestors
Species
a group of organisms that have similar anatomical characteristics that can interbreed and produce viable, fertile offspring
adaptation
a heritable characteristic that increases an organism's ability to survive and reproduce in an environment
fossil
a preserved remnant or impression of an organism
divergent evolution
also called adaptive radiation. The process in which a single species evolves into diverse species that live in different ways
Each of the following is an example of stabilizing, disruptive, or directional selection. Choose the correct term for each example, explain why it fits that category and sketch the appropriate graph. Panthers with teeth that are too short have difficulty capturing prey, while panthers with teeth that are too long have difficulty chewing their food.
stabilizing
Each of the following is an example of stabilizing, disruptive, or directional selection. Choose the correct term for each example, explain why it fits that category and sketch the appropriate graph. Spotted brown-and-white butterflies blend into lichen-covered tree bark, making it difficult for predators to see them, while solid brown and solid white butterflies are easier to see and get eaten.
stabilizing
homologuous structures
structures in different species that have different functions because of common ancestry
analogous structures
structures in different species that have similar functions due to convergent evolution but do not descend from a common ancestor
jean baptiste lamarck
suggested that organisms could change during their lifetimes by selectively using or not using various parts of their bodies. He also suggested that individuals could pass these acquired traits on to their offspring, enabling species to change over time. "inheritance of acquired characteristics"
directional selection
the form of natural selection in which individuals at one end of a distribution curve have a higher fitness than individuals in the middle or the other end of the curve
disruptive selection
the form of natural selection in which individuals at the upper and lower ends of the curve have a higher fitness than individuals near the middle of the curve
stabilizing selection
the form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve
variation
the presence of differences in sequences of genes between individual organisms of a species, It enables natural selection, one of the primary forces driving the evolution of life
natural selection
the process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest
coevolution
the process by which two species evolve in response to changes in each other over time
convergent evolution
the process in which unrelated species come to look alike because they have evolved similar adaptations in response to similar environments
parallel evolution
the process where different species with common ancestors independently develop similar traits or features in different geographic locations that have similar environmental conditions
artificial selection
the selective breeding of domesticated plants and animals to promote the occurrence of desirable traits