Comments on: Did a disease kill the sloths? http://slothcentral.com/archives/20 A 12,000 year-old mystery in SW Iowa Tue, 20 Apr 2010 02:51:50 -0700 http://wordpress.org/?v=2.8.4 hourly 1 By: David http://slothcentral.com/archives/20/comment-page-1#comment-46 David Tue, 17 Jun 2008 18:49:18 +0000 http://slothcentral.com/?p=20#comment-46 Travis, You're right. We would have preferred cool and dry conditions for preservation. It would have been better still if we had found the sloths embedded in a glacier, but wet anoxic conditions similar to ours have yielded DNA too. (See Hagelberg and Clegg, 1991, Lawlor et al., 1991, Paabo et al., 1988) Even at a single site conditions can vary a lot and produce different results with respect to DNA recovery. (See Stone and Stoneking, 1999; Hagelberg, E, Clegg JB. 1991.) The other important point is the hydroxyapatite mineral structure of bone offers some protection to the biomolecules inside, including DNA--the better the bone preservation, the better the chances for DNA survival (Hagelberg et al. 1989). The first look at our bone says the histology is excellent. So there are good reasons to be hopeful. Hagelberg, E, Sykes, B, Hedges, R. 1989. Ancient bone DNA amplified. Nature 342: 485. Hagelberg, E, Clegg JB. 1991. Isolation and characterization of DNA from archaeological bone. Proceedings of the Royal Society of London. Biological Science 244: 45-50. Lawlor, DA, Dickel, CD, Hauswirth, WW, Parham, P. 1991. Ancient HLA genes from 7,500-year-old archaeological remains. Nature: 349: 785-788. Paabo, S., Gifford, JA, Wilson, AC. 1988. Mitochondrial DNA sequences from a 7000-year-old brain. Nucleic Acids Research 16: 9775-9787. Stone, AC, Stoneking, M. 1999. Analysis of ancient DNA from a prehistoric Amerindian cemetery. Philosophical Transactions. Royal Society of London, B. Biological Science: 354(1379): 153-159. Travis, You’re right. We would have preferred cool and dry conditions for preservation. It would have been better still if we had found the sloths embedded in a glacier, but wet anoxic conditions similar to ours have yielded DNA too. (See Hagelberg and Clegg, 1991, Lawlor et al., 1991, Paabo et al., 1988) Even at a single site conditions can vary a lot and produce different results with respect to DNA recovery. (See Stone and Stoneking, 1999; Hagelberg, E, Clegg JB. 1991.) The other important point is the hydroxyapatite mineral structure of bone offers some protection to the biomolecules inside, including DNA–the better the bone preservation, the better the chances for DNA survival (Hagelberg et al. 1989). The first look at our bone says the histology is excellent. So there are good reasons to be hopeful.

Hagelberg, E, Sykes, B, Hedges, R. 1989. Ancient bone DNA amplified. Nature 342: 485.

Hagelberg, E, Clegg JB. 1991. Isolation and characterization of DNA from archaeological bone. Proceedings of the Royal Society of London. Biological Science 244: 45-50.

Lawlor, DA, Dickel, CD, Hauswirth, WW, Parham, P. 1991. Ancient HLA genes from 7,500-year-old archaeological remains. Nature: 349: 785-788.

Paabo, S., Gifford, JA, Wilson, AC. 1988. Mitochondrial DNA sequences from a 7000-year-old brain. Nucleic Acids Research 16: 9775-9787.

Stone, AC, Stoneking, M. 1999. Analysis of ancient DNA from a prehistoric Amerindian cemetery. Philosophical Transactions. Royal Society of London, B. Biological Science: 354(1379): 153-159.

]]> By: David http://slothcentral.com/archives/20/comment-page-1#comment-36 David Tue, 03 Jun 2008 21:15:38 +0000 http://slothcentral.com/?p=20#comment-36 Rob, thanks for the terrific tip. Rothschild published a paper on the subject two years ago. see http://news.nationalgeographic.com/news/2006/10/061003-mastodons.html He believes it only weakened the animals and didn't kill them outright but that virtually every one was infected. Add tuberculosis to the list of pathogens that infects many species. Per NCBI, Mycobacterium tuberculosis and M. tuberculosis-like organisms have been identified in a wide range of species, including primates, elephants, ungulates, carnivores, marine mammals and parrots. However, it's normally limited to captive settings and does not occur naturally in free-living populations (that's the social system barrier MacPhee refers to). See http://www.ncbi.nlm.nih.gov/pubmed/11288517 Low virulence and poor transmission knock M. tuberculosis out of contention for the super bug, at least in its current form, but Rothschild would say keep your mind open for it still being a contributing factor. Thanks again. Rob, thanks for the terrific tip. Rothschild published a paper on the subject two years ago. see http://news.nationalgeographic.com/news/2006/10/061003-mastodons.html He believes it only weakened the animals and didn’t kill them outright but that virtually every one was infected. Add tuberculosis to the list of pathogens that infects many species. Per NCBI, Mycobacterium tuberculosis and M. tuberculosis-like organisms have been identified in a wide range of species, including primates, elephants, ungulates, carnivores, marine mammals and parrots. However, it’s normally limited to captive settings and does not occur naturally in free-living populations (that’s the social system barrier MacPhee refers to). See http://www.ncbi.nlm.nih.gov/pubmed/11288517 Low virulence and poor transmission knock M. tuberculosis out of contention for the super bug, at least in its current form, but Rothschild would say keep your mind open for it still being a contributing factor. Thanks again.

]]> By: travis foxx http://slothcentral.com/archives/20/comment-page-1#comment-33 travis foxx Tue, 03 Jun 2008 07:12:01 +0000 http://slothcentral.com/?p=20#comment-33 If the sloth fossils have been buried in wet clay for 12,000 years is there much chance you'll be able to recover any DNA? I understand that's about as bad as it gets, right? If sitting frozen in ice is best, wouldn't sitting DRY in a cave be your only other hope? If the sloth fossils have been buried in wet clay for 12,000 years is there much chance you’ll be able to recover any DNA? I understand that’s about as bad as it gets, right? If sitting frozen in ice is best, wouldn’t sitting DRY in a cave be your only other hope?

]]> By: Robert McAfee http://slothcentral.com/archives/20/comment-page-1#comment-28 Robert McAfee Thu, 29 May 2008 23:12:27 +0000 http://slothcentral.com/?p=20#comment-28 I'm reminded of evidence of tuberculosis that was either found in museum specimens (osteological) of modern elephants or in the extinct mammoths and/or mastodons . I really wish I could remember the exact source or citation, but such an occurrence does increase the potential of disease occurring in the extinct sloths. A better source to inquire about this would be Bruce Rothschild - although he tends to believe sloths show a number of pathologies which more than anything are just sloths being sloths! I’m reminded of evidence of tuberculosis that was either found in museum specimens (osteological) of modern elephants or in the extinct mammoths and/or mastodons . I really wish I could remember the exact source or citation, but such an occurrence does increase the potential of disease occurring in the extinct sloths.
A better source to inquire about this would be Bruce Rothschild – although he tends to believe sloths show a number of pathologies which more than anything are just sloths being sloths!

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