Anthro 410 Exam 2025

Which of the following is a species according to the biological species concept? (A) All hominin species (most are fossil species). (B) A population of bacteria for which 80% of their DNA sequences are identical. (C) All allopolyploid plants. (D) A group of beetles that can intermate and produce offspring for multiple generations. - Correct Ans-D Which of the following is NOT a reason that Species are difficult to define? (A) Many plants that are genetically divergent are able to mate (B) Many organisms that are morphologically similar are genetically distinct (C) Many organisms are asexual (D) Sometimes groups split off from within a monophyletic group (such as birds splitting off from the reptiles) (E) Sometimes sexual populations that are unable to interbreed could still be the same biological species - Correct Ans-E Which of the following is most likely to be a "species" according to the Phylogenetic Species Concept? (a) A population of bacteria that has a gene that allows glucose metabolism (b) Bird populations, which share a unique heritable feather structure (c) Spider populations that can interbreed and produce fertile offspring (d) Crustacean populations that form a clade (geneticallyrelated group), except for one population within the clade that colonized land and became insects (e) Populations of deer that share similar antler shape - Correct Ans-B Under which of the following scenarios is reinforcement most likely to evolve? (a) Different fish species, with each living in a separate pond (b) Two snail species, where each lives on opposite sides of a freeway (c) Different species of crickets living together in a park, where hybrids between them have low survival rates (d) Different insect species, each living on a different ANTHRO 410 HSC 1149 species of fruit in a forest (e) Different species of allopolyploid plants living in a field - Correct Ans-C Sometimes the Molecular Clock (based on genetic data) conflicts with the Geological Record. Why would this happen? (A) Sometimes there are gaps in the geological record, because fossils do not form everywhere, and mutation rate might vary between different species (B) Radiometric dating relies on chance events in the preservation of isotopes, making the timing events in the geological time scale less accurate than the molecular clock (C) Mutation rates slow down as you go back in time, making estimation of timing of events less accurate as you go back in time (D) The molecular clock is calculated from radioisotopes, while the geological record is obtained from fossil data. The two can conflict when fossils end up displaced from their original sedimentary layer - Correct Ans-A Which of the following is most TRUE regarding phylogenetic reconstructions? (A) Phylogenetic reconstruction based on any gene would yield the same tree (B) Parsimony is the most accurate method for reconstructing phylogenies (C) Some DNA sequence data is better for phylogenetic reconstruction than others, such as those that tend to be less subjected to selection (3rd codon, introns) (D) Maximum likelihood relies on maximizing distances among taxa - Correct Ans-C Which of the following types of data would be most optimal for constructing a phylogeny? (a) Non-coding and regulatory sequences (b) Non-coding and non functional sequences (c) Paralogous genes (d) Genes that have undergone purifying selection (e) Intron sequences within rapidly evolving genes - Correct Ans-B Which of the following reasons is FALSE on why the type of data chosen in the question above would be optimal for constructing a phylogeny? (a) Because selection might make taxa seem more ANTHRO 410 HSC 1149 closely related due to convergent evolution (b) Because selection might make taxa seem more distantly related due to disruptive evolution (c) Because selection might make taxa seem more closely related due to purifying selection (d) Because non-coding regulatory sequences are likely to be neutral (e) Because coding sequences are likely to be under selection - Correct Ans-D How might microevolutionary mechanisms (genetic drift, selection, mutation) lead to the formation of new species? Which of the following is FALSE? (A) Disruptive selection could act to cause genetic differentiation between two populations (B) Hybrid breakdown between two populations can be a key factor (C) Mutations could accumulate in two populations and become fixed through selection or genetic drift, leading to hybrid sterility or inviability (D) Genetic drift is thought to be more effective at causing two populations to diverge and become separate species than natural selection (E) Geographic separation between two populations could start the process of speciation - Correct Ans-D You are a geneticist working for an agricultural research firm. Your job is to create new crop species of commercial value. You decide to hybridize two species that differ in chromosome number, and end up with hybrids with a chromosome number that differs from its parents. Which of the following is most FALSE? (A) You have created a new allopolyploid species. (B) Such species created through hybridization are always sterile, and can never reproduce without human assistance because the chromosomes cannot line up during meiosis. (C) Such new species are often more vigorous (greater fitness, growth rate) than either parent species because of fixed heterosis (heterozygous across loci). (D) Such ability for very different plants species to hybridize poses a challenge to the biological species concept and is a major mechanism for speciation in plants. - Correct Ans-B Which of the following is TRUE regarding speciation (the formation of new species)? (a) Speciation requires geographic separation (b) Dobzhansky-Müller incompatibilities can result in more rapid speciation in asexual species (c) Dobzhansky-Müller incompatibilities require changes in ANTHRO 410 HSC 1149 "speciation genes," or genes that affect reproduction (sperm coat protein, sperm motility, etc.) (d) Speciation requires disruptive selection to act (e) None of the above - Correct Ans-E Many polyploids become diploids over time. Which of the following is NOT a contributing cause or mechanism of diploidization? (a) The key event is the switch from having four (or more) chromosomes line up during meiosis to having two chromosomes line up during meiosis (b) Diploidization occurs so that the organism could revert back to the more compact genome size and similar gene number prior to polyploidization (c) Some gene copies lose function due to random mutations (d) Some gene copies become novel genes due to random mutations (e) Some homologous gene copies become transposed to other parts of the genome and become new genes - Correct Ans-B Which of the following scenarios is likely to lead to the most rapid formation of new species? (a) Two populations become geographically separated, and there is continued migration between the populations (b) Two populations become geographically separated, and then new mutations arise in each population that become fixed due to genetic drift (c) Two populations that are in the same location diverge due to sexual selection for different traits in the two populations (d) Two populations become geographically separated, and then new mutations arise in each population that become fixed due to selection favoring different egg coat proteins in the different habitats (e) All of the above would on average lead to equivalent rates of speciation - Correct Ans-D Which of the following is FALSE regarding hox Genes? (a) They serve the role of defining segmental regions along the anterior to posterior axis during development (b) Their functions have diversified through gene duplications followed by differentiation (e.g. subfunctionalization), leading to differentiation of segmental regions in animals (c) They encode transcription factors that perform trans-regulatory functions ANTHRO 410 (d) They are responsible for the major differences among animal phyla (e) They function by allowing or disallowing developmental sub-circuits to function within segmental regions (like an "on/off" switch) - Correct Ans-D Which of the following would be most evolutionary constrained? (a) Plug-ins of the GRN (b) Kernels of the GRN (c) Input/Output devices (d) Gene batteries (e) Hox genes - Correct Ans-B Changes at which below are most likely to be responsible for the radiation of animal phyla? (a) Plug-ins of the GRN (b) Sonic Hedgehog (c) Input/Output devices (d) Gene batteries (e) Kernels of the GRN - Correct Ans-E What are hox genes within an individual animal? (a) Orthologs (b) Paralogs (c) Homologs (d) Xenologs (e) None of the above - Correct Ans-B Developmental evolutionary differences between humans and chimpanzees are most likely to be at the level of (a) Plug-ins of the GRN (b) hox genes (c) Input/Output devices (d) Gene batteries (e) Kernels - Correct Ans-D Which statement is FALSE regarding genetic differences between humans and other apes? (a) There are structural evolutionary differences in the alleles of FOXP2 that are unique to Homo sapiens and Homo neanderthalensis versus those of chimpanzees (b) The genome sequences of humans and other great HSC 1149 ANTHRO 410 HSC 1149 apes are mostly identical, with less than 2% differences in coding sequences (c) Some key differences between human and chimpanzee gene expression appear to be due to differences in expression of transcription factors (d) The transcription factors that differ in expression between humans and chimpanzees form networks of coordinately-regulated genes (all up or down in expression as a unit) (e) Most genetic differences between humans and chimps appear to be due to cis-regulatory changes - Correct Ans-E Which of the following is FALSE regarding human brain evolution? (a) Rapid brain evolution in humans is likely due to evolutionary changes in developmental genes (b) Rapid brain evolution in humans might involve rapid evolution of expression of trans-acting factors, such as microRNAs (c) Percentage of genes that are differentially expressed between humans and chimpanzees are much greater in the brain than in other tissues, such as the testis (male sex organs) (d) Rapid brain evolution in humans might involve rapid evolution of expression of trans-acting factors, such as transcription factors (e) A gene deletion of a tumor suppressor gene that allowed growth in the brain might also allow the proliferation of cancer, leading to an evolutionary tradeoff - Correct Ans-C What are some anatomical features that do NOT distinguish humans from other great apes? (a) Bipedalism (b) Low brain to body size ratio in Homo (c) Shape of the pelvis (d) Language (e) Reduction in tooth and jaw size in Homo - Correct Ans-B Which of the following is FALSE regarding genetic differences between humans and their closest relatives (chimpanzees)? (A) Most of the DNA sequences are identical between humans and chimps; only about 1.6% of total sequence, an