Although it may never be possible to recover DNA from dinosaurs, ancient DNA of more recent vintage can help us understand more about the physiology and behavior of extinct animals. For example, researchers have extracted DNA from 43,000-year-old wooly mammoths that were preserved in the permafrost of Siberia. (Cold climates are especially favorable for preserving ancient DNA.) The investigators were able to sequence some of the DNA, including the genes that produced hemoglobin (a protein that transports oxygen in the blood). The researchers then inserted the mammoth hemoglobin genes into bacteria. The bacteria produced hemoglobin molecules just like those that circulated in the mammoth’s blood when it was alive.
Unlike hemoglobin from modern elephants, mammoth hemoglobin releases oxygen readily not only at core body temperature, but also at temperatures near freezing. Thus, though a modem elephant must keep its legs warm in order to provide oxygen to its leg muscles, a mammoth’s legs could get very cold and still function, an adaptation that helped the animals survive in ice-age Siberia.
In the end, mammoths became extinct, as do all species, eventually. What was responsible for history’s largest waves of extinction?
Want to see the full answer?
Check out a sample textbook solutionChapter 18 Solutions
Biology: Life on Earth with Physiology (11th Edition)
- 2b)An ancient gene underwent duplication during the course of evolution to yield two chain genes designated as δ and ε genes. Jessica’s final year project deals with the metagenomic studies of anfH homologous genes from freshwater lake samples in Kampar Eastlake. She successfully cloned and sequenced two partial anfH homologous gene sequences.BlastX analyses revealed that one of the DNA sequences showed highestsimilarity to AnfH protein from a Brazilian soil bacteria isolate while the second sequence showed highest identity to the AnfH protein sequence of a bacterium that was isolated from Tonle Sap, a freshwater lake in Cambodia. To determine their evolutionary relationship, she subsequently constructed a phylogenetic tree using the corresponding protein sequences. Describe the steps that are required toperform the analysis.arrow_forwardYou just graduated from college and started working at a biotech startup called Scrofabulous. Your first job assignment is to clone the pig gene for the hormone prolactin. Assume that the pig gene for prolactin has not yet been isolated, sequenced, or mapped; What would be the most useful and economical first step to go about identifying and cloning the pig gene for prolactin? use the amino acid sequence of mouse prolactin to design a pair of degenerate oligonucleotide PCR primers to PCR-amplify the pig prolactin gene. RNAseq the pituitary gland of the pig, the most abundant gene is likely to to be prolactin Conduct a proteome search for peptides that match parts of mouse prolactin protein Sequence the pig genome, then translate the genome to find the gene predicted to encode for prolactin Crystalize the mouse prolactin protein and use Google's DeepMind Al to find the closest amino acid sequence in the pig proteomearrow_forwardA molecular geneticist hopes to find a gene in human liver cells that codes for an important blood-clotting protein. He knows that the nucleotide sequence of a small part of the gene is GTGGAСTGACA. Briefly explain how to obtain the desired gene.arrow_forward
- Which of the following statements concerning recombinantDNA technology is false?(a) Thus far, no illnesses in laboratory workers have beentraced to genetic recombinants.(b) Production of large amounts of proteins such as insulinand human growth hormone has been made possible us-ing recombinant DNA technology.(c) Recombinant DNA technology offers specific benefitsto the scientific, medical, and general populations.(d) Mutant strains of bacteria produced by genetic re-combination are often unable to survive in the naturalenvironment.(e) Recombinant DNA technology provides a high degreeof risk to the health of the general populations.arrow_forwardThe Selfish Gene is a radical theory that argues that all living creatures are essentially vehicles for their genes- hence, we all are a “survival machine" for our genes. In the light of what you have learned about the molecular structure and function of the gene, is this perspective still relevant? Cite specific biological phenomena to prove your point. References:arrow_forwardNucleic acids are isolated and analyzed from different cells in a mammal. How would the DNA sequence of a skin cell be different from the DNA of a nerve cell? How would the RNA isolated from a skin cell and a nerve cell be different? A stem cell is a cell that is not currently differentiated into a specific cell type but that retains the capacity to differentiate into different cell types (such as nerve and skin). How does the existence of stem cells help verify your answer to the preceding questions?arrow_forward
- A fairly conserved gene is compared between a human, a chimpanzee, a bear and a banana. How would you expect their DNA sequences to relate?arrow_forwardHighly conserved genes such as those for ribosomal RNA are present as clearly recognizable relatives in all organisms on Earth; thus, they have evolved very slowly over time. Were such genes “born” perfect?arrow_forwardPlease asaparrow_forward
- Scientists have observed that individuals with LOW birthweight are MORE likely to become obese as teenagers. To study this observation in more depth, a scientist compared the methylation of the promoter region of the leptin gene in low birthweight (LBW) and normal birthweight (NBW) individuals by treating isolated DNA from these individuals with bisulfite and comparing the results to untreated DNA. The results are shown below. What conclusion can you draw? Untreated: ATTCGATTCGCGAA Treated NBW: ATTCGATTCGCGAA Treated LBW: ATTTGATTCGTGAA Scientists have observed that individuals with LOW birthweight are MORE likely to become obese as teenagers. To study this observation in more depth, a scientist compared the methylation of the promoter region of the leptin gene in low birthweight (LBW) and normal birthweight (NBW) individuals by treating isolated DNA from these individuals with bisulfite and comparing the results to untreated DNA. The results are shown below. What…arrow_forwardA genetics research group has determined the sequence of a rat gene thought to be involved in controlling the fertilising ability of rat sperm. They believe a similar gene may control fertility in humans. Describe how what is known about the rat gene can be applied in PCR to clone the complementary human gene. You should explain the experimental approach taken and how it could confirm that the human gene in question does indeed correspond to the rat gene.arrow_forwardDifferent mutations in the WDR62 gene that inactivate gene function were found in the genomes of many different people with microcephaly. This information provided strong support for the idea that the WDR62 gene mutation causes microcephaly. A.The human genome sequence identified WDR62 as one of the approximately 27, 000 genes in the human genome. What information about the function of WDR62 do you think was learned originally from the DNA sequence of the normal human genome?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