Age and growth estimates of bowhead whales (Balaena mysticetus) via aspartic acid racemization

1999 ◽  
Vol 77 (4) ◽  
pp. 571-580 ◽  
Author(s):  
John C George ◽  
Jeffrey Bada ◽  
Judith Zeh ◽  
Laura Scott ◽  
Stephen E Brown ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Standard Error ◽  
Sexual Maturity ◽  
Delta Method ◽  
Age And Growth ◽  
Eye Lens ◽  
Bowhead Whales ◽  
Aspartic Acid Racemization ◽  
Coefficients Of Variation ◽  
Age Estimates

A total of 48 eye globes were collected and analyzed to estimate ages of bowhead whales using the aspartic acid racemization technique. In this technique, age is estimated based on intrinsic changes in the D and L enantiomeric isomeric forms of aspartic acid in the eye lens nucleus. Age estimates were successful for 42 animals. Racemization rate (kAsp) for aspartic acid was based on data from earlier studies of humans and fin whales; the estimate used was 1.18 10-3/year. The D/L ratio at birth ((D/L)0) was estimated using animals less than or equal to 2 years of age (n = 8), since variability in the D/L measurements is large enough that differences among ages in this range are unmeasurable. The (D/L)0 estimate was 0.0285. Variance of the age estimates was obtained using the delta method. Based on these data, growth appears faster for females than males, and age at sexual maturity (age at length 12-13 m for males and 13-13.5 m for females) occurs at around 25 years of age. Growth slows markedly for both sexes at roughly 40-50 years of age. Four individuals (all males) exceed 100 years of age. Standard error increased with estimated age, but the age estimates had lower coefficients of variation for older animals. Recoveries of traditional whale-hunting tools from five recently harvested whales also suggest life-spans in excess of 100 years of age in some cases.

Age and growth estimates of bowhead whales (Balaena mysticetus) via aspartic acid racemization

1999 ◽  
Vol 77 (4) ◽  
pp. 571-580 ◽  
Author(s):  
John C. George ◽  
Jeffrey Bada ◽  
Judith Zeh ◽  
Laura Scott ◽  
Stephen E. Brown ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Age And Growth ◽  
Balaena Mysticetus ◽  
Bowhead Whales ◽  
Aspartic Acid Racemization

A new way to estimate the age of bowhead whales (Balaena mysticetus) using ovarian corpora counts

2011 ◽  
Vol 89 (9) ◽  
pp. 840-852 ◽  
Author(s):  
J.C. George ◽  
E. Follmann ◽  
J. Zeh ◽  
M. Sousa ◽  
R. Tarpley ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Sexual Maturity ◽  
Standard Errors ◽  
Reproductive Parameters ◽  
Balaena Mysticetus ◽  
Bowhead Whales ◽  
Aspartic Acid Racemization ◽  
Sexually Mature ◽  
Age Estimates

We used lengths and reproductive data for bowhead whales ( Balaena mysticetus L., 1758) harvested by Alaskan Eskimos to estimate female reproductive parameters and age. Data from 117 females determined that 75 were sexually mature and 42 were immature. Estimated length at sexual maturity was 13.35 m. Counts of ovarian corpora were obtained from 50 mature females. Corpora and baleen data were used with aspartic acid racemization (AAR) data to obtain estimated age at sexual maturity (ASM) at ≈26 years. The number of corpora counted in both ovaries (or estimated when only one ovary was counted) was used with ASM and estimated ovulation rate (OR) to obtain corpora age estimates ranging from 26 to 149 years. A stone harpoon tip recovered from whale 92B2 was consistent with her corpora age of 133 years. The correlation between corpora and AAR age estimates was 0.77. Estimated standard errors of corpora ages tended to be somewhat higher than those for comparable AAR ages. A sample of potentially mature females examined for maturity and presence of a corpus luteum and (or) fetus provided an OR value of 0.332·year–1 and an estimated pregnancy rate of 0.326·year–1, implying intervals between ovulations and pregnancies of 3.0 and 3.1 years.

scholarly journals Non-Concordance of Radiocarbon and Amino Acid Racemization Deduced Age Estimates on Human Bone

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 647-654 ◽  
Author(s):  
R E Taylor
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Human Bone ◽  
Amino Acid Racemization ◽  
Aspartic Acid Racemization ◽  
Order Of Magnitude ◽  
Direct Counting ◽  
Organic Fractions ◽  
Skeletal Samples ◽  
Age Estimates

Radiocarbon determinations, employing both decay and direct counting, were obtained on various organic fractions of four human skeletal samples previously assigned ages ranging from 28,000 to 70,000 years on the basis of their D/L aspartic acid racemization values. In all four cases, the 14C values require an order of magnitude reduction in age.

scholarly journals Accuracy of the Aspartic Acid Racemization Technique in Age Estimation of Mammals and the Influence of Body Temperature

2018 ◽  
Vol 10 ◽  
Author(s):  
Eva Garde ◽  
Mads F. Bertelsen ◽  
Susanne Ditlevsen ◽  
Mads Peter Heide-Jørgensen ◽  
Nynne H. Nielsen ◽  
...  
Keyword(s):  
Body Temperature ◽  
Aspartic Acid ◽  
Age Estimation ◽  
Postnatal Growth ◽  
Capra Hircus ◽  
Eye Lens ◽  
Mean Squared Errors ◽  
Aspartic Acid Racemization ◽  
Species Specific ◽  
Leave One Out

The aspartic acid racemization (AAR) technique has been applied for age estimation of humans and other mammals for more than four decades. In this study, eye lenses from 124 animals representing 25 mammalian species were collected and D/L ratios obtained using the AAR technique. The animals were either of known age or had the age estimated by other methods. The purpose of the study was to: a) estimate the accuracy of the AAR technique, and b) examine the effect of body temperature on racemization rates. Samples from four of the 25 species covered the range of ages that is needed to estimate species-specific racemization rates. The sample size from a single species of known age, the pygmy goat (Capra hircus, n = 35), was also large enough to investigate the accuracy of ages obtained using the AAR technique. The 35 goats were divided into three datasets: all goats (n = 35), goats >0.5 yrs old (n = 26) and goats >2 yrs old (n = 19). Leave-one-out analyses were performed on the three sets of data. Normalized root mean squared errors for the group of goats >0.5 yrs old were found to be the smallest. The higher variation in D/L measurements found for young goats <0.5 yrs can probably be explained by a period of continued postnatal growth of the eye lens. Normalized root mean squared errors from the leave-one-out cross-validation analyses based on goats >0.5 yrs old was for three age groups of the goats: 0.934 yrs for young goats <2 yrs (n = 16), 0.102 yrs for adult goats from 2–8 yrs (n = 15) and 0.133 yrs for old goats >8 yrs (n = 4). Thus, the age of an adult or an old animal can be predicted with approximately 10% accuracy, whereas the age of a young animal is difficult to predict. A goat specific racemization rate, as a 2kAsp value, was estimated to 0.0107 ± 3.8 x 10-4 SE (n = 26). The 2kAsp values from 12 species, four estimated in this study and another eight published, were used to examine the effect of core body temperature on the rate of racemization. A positive relationship between AAR and temperature was found (r2 = 0.321) but results also suggest that other factors besides temperature are involved in the racemization process in living animals. Based on our results we emphasize that non-species-specific racemization rates should be used with care in AAR age estimation studies and that the period of postnatal growth of the eye lens be considered when estimating species-specific D/L0 values and ages of young individuals.

Amino Acid Geochemistry of Fossil Bones from the Rancho La Brea Asphalt Deposit, California

1982 ◽  
Vol 18 (2) ◽  
pp. 174-183 ◽  
Author(s):  
Mark A. S. McMenamin ◽  
David J. Blunt ◽  
Keith A. Kvenvolden ◽  
Scott E. Miller ◽  
Leslie F. Marcus ◽  
...  
Keyword(s):  
Amino Acids ◽  
Los Angeles ◽  
Aspartic Acid ◽  
Equivalent Age ◽  
Aspartic Acid Racemization ◽  
Wide Range ◽  
Fossil Bones ◽  
Minimum Age ◽  
Rancho La Brea ◽  
Age Estimates

AbstractLow aspartic acid d:l ratios and modern collagenlike concentration values indicate that amino acids in bones from the Rancho La Brea asphalt deposit, Los Angeles, California are better preserved than amino acids in bones of equivalent age that have not been preserved in asphalt. Amino acids were recovered from 10 Rancho La Brea bone samples which range in age from less than 200 to greater than 36,000 yr. The calibrated rates of aspartic acid racemization range from 2.1 to 5.0 × 10−6yr−1. Although this wide range of rate constants decreases the level of confidence for age estimates, use of the larger rate constant of 5.0 × 10−6yr−1provides minimum age estimates which fit the known stratigraphic and chronologic records of the Rancho La Brea deposits.

scholarly journals Estimating narwhal ( Monodon monoceros ) age using tooth layers and aspartic acid racemization of eye lens nuclei

2019 ◽  
Vol 36 (1) ◽  
pp. 103-115 ◽  
Author(s):  
Cortney A. Watt ◽  
Barbara E. Stewart ◽  
Lisa Loseto ◽  
Thor Halldorson ◽  
Steven H. Ferguson
Keyword(s):  
Aspartic Acid ◽  
Eye Lens ◽  
Aspartic Acid Racemization ◽  
Monodon Monoceros

scholarly journals Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

2012 ◽  
Vol 31 (1) ◽  
pp. 15865 ◽  
Author(s):  
Eva Garde ◽  
Mads Peter Heide-Jørgensen ◽  
Susanne Ditlevsen ◽  
Steen H. Hansen
Keyword(s):  
Aspartic Acid ◽  
Eye Lens ◽  
Aspartic Acid Racemization ◽  
Monodon Monoceros

scholarly journals Estimating the Age of West Greenland Humpback Whales Through Aspartic Acid Racemization and Eye Lens Bomb Radiocarbon Methods

2020 ◽  
Vol 6 ◽  
Author(s):  
Tenna K. Boye ◽  
Eva Garde ◽  
Julius Nielsen ◽  
Rasmus Hedeholm ◽  
Jesper Olsen ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Humpback Whales ◽  
Eye Lens ◽  
West Greenland ◽  
Aspartic Acid Racemization ◽  
Bomb Radiocarbon

scholarly journals Use of AMS 14C Analysis in the Study of Problems in Aspartic Acid Racemization-Deduced Age Estimates on Bone

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 539-546 ◽  
Author(s):  
Paul Ennis ◽  
E A Noltmann ◽  
P E Hare ◽  
P J Slota ◽  
L A Payen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Chemical State ◽  
Fossil Bone ◽  
Aspartic Acid Racemization ◽  
Age Estimates

Major discordances between AMS 14C- and aspartic acid racemization (AAR)-deduced age estimates on bone samples have led to an examination of factors other than time and temperature that can fundamentally influence the degree of racemization observed in fossil bone. Our studies support previous suggestions that for many bone samples the chemical state of amino acids must be routinely considered if AAR-deduced age estimates are to be used to make meaningful chronologic inferences.

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