Concept explainers
Whale skeletons contain nonfunctional pelvic bones
a. as a result of convergent evolution.
b. due to catastrophism.
c. because whales evolved from ancestors that had hind legs.
d. because the bones might be needed for a future adaptation.
Introduction:
The vestigial can be referred to a rudimentary structure present in the body of an organism, which does not have any prominent function. These structures were functional in the ancestors of the organism, but during the course of evolution, the organism loses its function.
Answer to Problem 1MC
Correct answer:
The pelvic bone in the whales is a vestigial organ, which had a function in their ancestors, having hind limbs.
Explanation of Solution
Explanation for the correct answer:
Option (c) is given that the nonfunctional pelvic bones are present in whale’s skeleton as whales evolved from the ancestors that had hind legs. The whales are known to evolve from the Pakicetus. These organisms had four legs, and the hind limbs were functional. During the evolution, the hind limbs were lost, but the pelvic bone is still present in the whales. Hence, option (c) is correct.
Explanation for the incorrect answers:
Option (a) is given that the nonfunctional pelvic bones are present in whale’s skeleton as a result of convergent evolution. The convergent evolution can be defined as the process, in which the closely related species independently evolve the similar structures or traits to adapt to the environment. However, the pelvic bones were present in the ancestor of the whales, this is not evolved. So, it is an incorrect option.
Option (b) is that the nonfunctional pelvic bones are present in whale’s skeleton due to catastrophism. The catastrophism referred to a change, which occurs suddenly in the organism. However, the pelvic bones are not suddenly developed in the whales, it is not an example of catastrophism. So, it is an incorrect option.
Option (d) is because that the nonfunctional pelvic bones are present in whale’s skeleton might be needed for a future adaptation. The bones of the pelvis were functional in the ancestors of the whales. This is not evolved for the future adaptation. So, it is an incorrect option.
Hence, options, (a), (b), and (d) are incorrect.
Thus, it can be concluded that pelvic bones are a vestigial organ in whales. These were functional in their ancestors, but in whales, they are nonfunctional.
Want to see more full solutions like this?
Chapter 15 Solutions
Biology: Life on Earth (11th Edition)
- The bones in the front fins of whales and the bones in the human arm evolved from a common ancestor but carry out different functions. This is an example of A. homologous structures. B. vestigial structures. C. analogous structures. D. embryonic structures.arrow_forwardDespite the differences in neck length, mice, humans, and giraffes all have seven cervical vertebrae. This is an illustration of A. missing links. B. homologous structures. C. vestigial structures. D. analogous structures.arrow_forwardWhich of the following is not true about human and ape skeletons?a. Humans have a long, narrow pelvis.b. A human’s spinal cord exits from the bottom of the skull.c. An ape’s arms are longer than its legs.d. An ape’s spinal column is slightly curvedarrow_forward
- You are studying the skeleton and bone morphology across reptiles. You find that in alligators a certain bone in the jaw has elongated whereas in a species of chameleon the bone has shortened in the jaw. In both species the bone still helps control feeding. Is this bone and skeletal morphology a homology? a. Yes, it is a homology b. No, it is not a homology c. Not enough information to tell d. The answer depends on the specific diet of each speciesarrow_forwardFossils of a dwarf species of human, Homo floresiensis, has been discovered on the Indonesian island of Flores. There has been debate as to who are the immediate ancestors. New fossils have just been discovered and dated at 700,000 years ago. This strongly suggests that their immediate ancestors are A. Homo habilis B. Homo neanderthalensis C. Ardipithecus D. Homo sapiens E. Homo erectusarrow_forwardWhat do the Homo erectus fossils from Sangiran, Java, demonstrate? A. H. erectus spread to Eastern Asia after spreading to Europe. B. H. erectus fossils are older in Asia than in Africa. C. H. erectus inhabited parts of Eastern Asia prior to living in Western Asia. D. H. erectus spread rapidly eastward from Western Asia.arrow_forward
- In your Introduction to Biological Anthropology class, your instructor asks you to examine a fossil skull and determine which species it is. You note there is a sagittal keel at the top of the skull. Based on this information alone, to which species does the skull belong? A. Australopithecus boisei B. Homo habilis C. Australopithecus garhi D. Homo erectusarrow_forwardFossilized remains of prehistoric mastodons show anatomical similarities to modern-day elephants. These similarities provided the first evidence that mastodons were related to modern-day elephants. Which of the following is the BEST additional evidence that mastodons were related to elephants? A. Mastodons walked on four legs like modern-day elephants. B. Mastodon tissues contained proteins with similar amino acid sequences compared to modern-day elephants. C. Mastodon fossils were found in the same area where modern-day elephants live. D. Mastodons ate a diet similar to that of modern-day elephants.arrow_forward.The skeletons of early fossil Homo and archaic Homo sapiens are marked by very ____ skeletons; this pattern demonstrates a dramatic ____ with the origin of modern humans. a. well designed; increase b. robustly built; decrease c. gracile; increase d. sturdy; increasearrow_forward
- A. Sex” refers to the observable physical characteristics that distinguish two kinds of humans, females and males. Select one: True False B. Palaeoanthropologists are biological anthropologists who study a. biological variation in living human populations. b. the fossils and remains of ancient human ancestors. c. human evolution using mitochondrial DNA. d. the material remnants of early human societies.arrow_forwardClassic Neanderthal limb bones suggest that: A. the Neanderthals probably had limited manual dexterity, which probably accounts for the crudeness of Mousterian (= Middle Paleolithic) stone tools. B. even Neanderthal children had difficulty walking erect. C. the Neanderthals were stocky, heavily muscled people. D. the Neanderthals averaged over six feet tall. E. the Neanderthals had apelike limb proportions, including exceptionally long arms.arrow_forwardWhat evidence is found in the fossil record that shows that early ancestors of humans walked upright and used bipedal locomotion? Select all that apply. a On the bottom of the skull, there is a place where the backbone attaches. b Fossilized bones of the hip and pelvis are shorter in height. c The feet evolved five toes from three toes. d The backbone was attached to the back of the skull.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education