Concept explainers
The unexpected discovery that humans interbred with Neanderthals was a triumph for the experts who developed the techniques for extracting, isolating, and sequencing ancient DNA. But perhaps the most stunning revelation made possible by ancient DNA was the discovery of the Denisovans, a hominin species whose existence would still be unknown if not for analysis of its ancient DNA. The fossil fragments from which the DNA was extracted were too few, too small, and too nondescript to have even been recognized as belonging to a previously unknown species. A newfound ability to identify new extinct species on the basis of DNA alone raises the intriguing possibility of future discovery of other previously unsuspected species, hommin and otherwise.
Like Neanderthals, Denisovans left a genetic trace in modern humans. One example is the Denisovan gene variant that helps Tibetans live at high altitude. Additionally, the people native to New Guinea and other Pacific islands carry a substantial number of Demsovan sequences. Almost 5% of the genome of these people is of Demsovan origin. This finding suggests that Denisovans interbred with the ancestors of Pacific Islanders, either in mainland Asia before the islands were first cotonized by people, or later, if Denisovans were somehow able to get to multiple islands.
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Biology: Life on Earth with Physiology (11th Edition)
- 8) Each of the observations provides evidence that supports the idea of common ancestry and evolution. Which one is from the field of molecular biology? A) Mammals have two openings in the skull behind each eye socket, whereas reptiles and bird only have one opening. B) DNA analysis shows that the DNA of Neanderthals is more similar to the DNA of non‑African humans than that of Africans. C) Two closely related but distinct species of squirrels inhabit the north and south rims of the Grand Canyon. D) The embryos of both birds and mammals divide in a radial cleavage pattern instead of a spiral cleavage pattern present in insects.arrow_forwardIn the book, Jurassic Park, by Michael Crichton, scientists are able to reconstruct dinosaurs by getting dinosaur DNA from a mosquito that had been well-preserved in amber since the era of dinosaurs. Do you believe this can actually happen in real life? Why?arrow_forwardExplain how evidence from modern human genomes supports a recent African origin for Homo sapiens. How have findings from ancient DNA altered the simple out-of-Africa model? this question is from a past paper i found, can it please be answered in extensive detail and in essay form as i feel it would benefit my personal revision to be able to answser a question of this nature about the topic.arrow_forward
- Cat DNA is much more similar to dog DNA than to tortoise DNA. Why? (a) Cats and dogs are both carnivores and take in similar nutrients. (b) Cats and dogs have lived together with humans for a long period of time, so they have grown more similar. (c) Cats and dogs have more offspring during their lifetime than tortoises have, so their DNA changes less rapidly. (d) Cats and dogs have a common ancestor that is more recent than the common ancestor of cats and tortoises.arrow_forwardAdvances in biotechnology have revolutionized the study of ancient remains. In Ötzi's case, a genetic study showed that his DNA most closely matched up with people that currently live in Sardinia. One hypothesis for this is that at Ötzi's time, a group of people with similar DNA spread throughout Europe including Sardinia. Sardinia is somewhat isolated so the DNA of the population living there has changed very little since that time. On mainland Europe, where his remains were found, there was more mixing of populations so there have been changes to the DNA profiles of the people living in that region. Questions: 1.) Based on the genetic results, do you think Ötzi should be considered Sardinian even though he lived in the Alps? Why or why not?arrow_forwardWhat do you think might be some of the problems associated with isolating and sequencing DNA from ancient samples, such as that of the 4000-year-old Saqqaq man from Greenland?arrow_forward
- There are two hypotheses to explain the pattern of Human Evolution: 1) Progressive Evolution of a Single Lineage ; 2) Evolutionary Radiation Which of these hypotheses are supported by evidence, and briefly explain why? Please explain in detailsarrow_forwardFill the blank New genes can arise during evolution through: (i) exonshuffling, which can alter the domain structure of proteins;(ii) duplication and divergence that generates gene families;and (iii)_______ mutations in intergenic DNA sequences.arrow_forwardcreate a phylogeny of human evolution. It should include all known hominids beginning with the earliest and ending with modern Homo sapiens. In your version of a future, humans will create a phylogeny of human evolution. It should include all known hominids beginning with the earliest and ending with modern Homo sapiens and your version of a future human. The requirement is to put the genus and species name of the hominid, beginning with the earliest one, which is Sehelanthropus tchadensis, in the phylogeny along with its dating age.arrow_forward
- A large public and private effort went into sequencing the human genome. What did this project hope to accomplish; how did emerging technology assist the project (ie recombinant DNA, super-computing, automated sequencing), was it successful and what is the usefulness of what was learned in this massive effort?arrow_forwardEven though paleontologists and anthropologists are continually finding new fossils, there is still a lack of fossils overall. Explain.arrow_forwardhttps://youtu.be/z9HIYjRRaDE?si=iysZqALCGUupgJlk Note: This video can also be found under the "What is evolution and how does it occur?" introduction tab in your lab module. You have already learned about how mutations can change the function of DNA and create new alleles. Write a short reflection (at least 5-6 sentences) connecting the main point of this video (that some mutations--such as duplicating a section of DNA--can lead to new genes) to your prior understanding of mutations from Life 102 lab. Focus on making connections and exploring your own thought processes. If you need help getting started, consider the following questions: •Did parts of the video reinforce or extend your understanding of mutations? How so? •Were there any parts of the video that were confusing to you or challenged your existing understanding of mutations? Why were those parts confusing or challenging? •What further questions do you have about mutations and the emergence of new genes as a result of…arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning