Concept explainers
Overall similarity of
a. due to convergent evolution.
b. because of variation in rates of evolutionary change of different kinds of characters.
c. due to homoplasy.
d. All of the choices are correct.
Introduction:
The phylogeny explains the evolutionary history of a species. Systematics can be used to construct a phylogeny which is an evolutionary tree which depicts the relationship among different species by studying the similarities or differences among different species.
Answer to Problem 1U
Correct answer:
The basis of the phylogenetic tree is the evolutionary relationship represented between different lineages to determine the relationship among species. Thus, it is necessary to study the reasons relating to these similarities. The similarities usually arise due common ancestors. But there are other reasons also due to which the phenotypic similarities could arise even without any evolutionary relationship. The similarity could arise due to homoplasy, convergent evolution and due to the different rate of changes in various kinds of characters. Therefore option d. is correct.
Explanation of Solution
Reason for the correct statement:
Overall similarity in phenotypes of two different species could arise due to various reasons even when they do not share any evolutionary relationship. It may be due to changes in rate of evolutionary divergences occurring in different kind of characters as the evolutionary change in two different characters could be at the same time and could lead to similarities.
Also convergent evolution where species of different lineages show common functions even though they have different structures due to different ancestral lineages. Similarities may also arise due to derived set of characters, even by the species belonging to different ancestor lineages.
Option d. is given as “All of the choices are correct”.
As, “overall similarity of phenotypes may not always reflect evolutionary relationships due to convergent evolution, because of variation in rates of evolutionary change of different kinds of characters and due to homoplasy”, is the right answer.
Hence, option d. is correct.
Reasons for the incorrect statements:
Option a. is given as “due to convergent evolution”.
Similarities in phenotypes could arise due to the convergent evolution where different animals show common functions even though they have different structures due to different ancestral lineages. So, it is a wrong answer.
Option b. is given as “because of variation in rates of evolutionary change of different kinds of characters”.
Similarities in phenotypes of different species could arise due to the different rate of evolutionary changes in different type of characters as different species will independently evolve the same derived character. But “due to convergent evolution and due to homoplasy” are also correct. So, it is a wrong answer.
Option c. is given as “due to homoplasy”.
Homoplasy represents the set of characters that are shared by the species of different ancestor lineages. There is no evolutionary relationship between these species due to different ancestor lineage, but similarity in functions and structures leads to the overall similarity in the phenotypes. Other options “due to convergent evolution and because of variation in rates of evolutionary change of different kinds of characters” are also correct. So, it is a wrong answer.
Hence options a., b., and c. are incorrect.
The similarities in different lineages could arise due to homoplasy or due to the convergent evolution. Also, due to different rate of evolutionary divergences occurring in different kind of characters as the evolutionary change in two different characters could be at the same time and could lead to similarities.
Want to see more full solutions like this?
Chapter 23 Solutions
Biology - With Access (Looseleaf) (Custom)
- Which of the following statement about the outcome of the evolution of a new species through hybridization is false? a.The new species may have traits that allow it to inhibit environments different from both parental species. b.The new species is always an intermediate of the two parental species c.The new species may have greater genetic diversity and greater trait diversity than the parental species. d.None of the above What are the two ways of looking into evolution in detail? a.Micro frequency change and ascent with modification b.Genotypic and phenotypic modification c.DNA frequency change and inheritance modification d.Allele frequency change and descent with modification Natural selection increases the frequencies of advantageous alleles and decreases deleterious alleles' frequencies. What are the three categories of natural selection depending on the favored traits? a.Directive, selective and native b.Indicative, normative and fixative c.Directional, stabilizing and…arrow_forwardDerived characters are traits: A. that are more complicated than ancestral characters B. that characterize the last common ancestor of a particular collection of species. C. that have evolved after the last common ancestor of a particulan collection of species. D. that are less well suited to the environment than ancestral characters.arrow_forwardTo apply parsimony to constructing a phylogenetic tree, (A) choose the tree that assumes all evolutionary changes are equally probable. (B) choose the tree in which the branch points are based on as many shared derived characters as possible. (C) choose the tree that represents the fewest evolutionary changes,in either DNA sequences or morphology. (D) choose the tree with the fewest branch points.arrow_forward
- You are evaluating five phylogenetic trees generated from a single cladistics analysis. Tree A shows 21 evolutionary events (i.e. the evolution of a shared, derived trait), Tree B shows 7 events, Tree C shows 18 events, Tree D shows 10 events, and Tree E shows 9 events. Which tree is most likely the correct one? Group of answer choices Tree A Tree D Tree B Tree E Tree Carrow_forwardYou are reading a scientific paper regarding the relationships of the anatomical and behavioral characteristics of chimpanzees and their implications for early hominid evolution. With the emphasis on anatomical and behavioral characteristics, this implies that the researchers are relying on A. Traditional classifications of chimpanzees and humans B. Nonevolutionary classifications of chimpanzees and humans C. An incorrect classification of human ancestors D. Cladistic classifications of chimpanzees and humansarrow_forwardDescribe three or more genetic mechanisms that may lead to the rapid evolution of a new species. Which of these genetic mechanisms are influenced by natural selection, and which are not?arrow_forward
- Mitochondrial DNA evidence has shown that____. a. the greatest diversity of mtDNA is in European peoples, suggesting they share a more recent origin b. the least diversity of mtDNA is in African peoples, suggesting Old World peoples share a more ancient origin c. the greatest diversity of mtDNA is in African peoples, suggesting they share a more ancient origin d. the least diversity of mtDNA is in European peoples, suggesting they share a more ancient originarrow_forwardWhy is molecular data for phylogenetic inference best analyzed with use of an explicit model of molecular evolution? A) This is true of morphological data, not molecular data, it is impossible to model changes in molecular sequence data because it is constantly evolving. B) Because molecular data is known to only experience random changes and is constantly evolving, a chaotic model of evolution can universally be applied to molecular sequence data for phylogenetic analysis. C) Because molecular data is known to experience non-random changes in terms of the likelihood of different types of mutations -- transitions vs. transversions, at different codon positions, which can be used to infer sequence evolution and relationship. D) None of the above.arrow_forwardWhy are human and chimpanzee DNA 96 percent similar? Please choose the best option.a) Both groups show similarities in their fossil record.b) Humans and chimpanzees share several similar traits such as the use of tools.c) These two species descended from a recent common ancestor.d) Natural selection has favored those particular genes in both humans and chimpanzees.arrow_forward
- Which of the following conclusions are MOST likely to be supported by genetic evidence? A. Some modern-day organisms did not exist in the past. B. Some organisms found in the fossil record do not currently exist. C. Environmental change affected the fitness of individuals differently based on their traits. D. Some disease-causing traits may remain in a population because their alleles provide an advantage to heterozygotes.arrow_forwardWhen two organisms are very distantly related in an evolutionary sense, (a) they should have extremely similar embryonic development. (b) they must share a very recent common ancestor. (c) the sequences of DNA in their genes should be less similar (more different) than those of two more closely related organisms. (d) they should share more homologous traits than two more closely related organisms share.arrow_forwardReduced tailbones and the associated remnant muscles in humans are an example of what type of evidence for common descent? (a) artificial selection (b) homologous traits (c) biogeography (d) fossil evidencearrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College