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Asiatic Lion - Data, Pictures & Videos
Asiatic Lion - Data, Pictures & Videos
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Asiatic Lion - Data, Pictures & Videos
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 (06-16-2014, 02:28 AM)Pckts Wrote:(06-14-2014, 09:48 PM)'tigerluver' Wrote:(06-14-2014, 05:17 PM)'Vinod' Wrote:  (06-16-2014, 04:27 AM)'tigerluver' Wrote:(06-16-2014, 02:28 AM)'Pckts' Wrote:There is no study that shows Tsavo lions having more testosterone than others, That I know of. That is my point, even if they did, that would specifically disprove this theory that testosterone is the main contributor to mane lentgth or color.(06-14-2014, 09:48 PM)'tigerluver' Wrote:(06-14-2014, 05:17 PM)'Vinod' Wrote:
Regarding testosterone and mane, you are missing my point. Do not think greater testosterone increases hair, it is most probably the opposite. Greater testosterone is linked to hair loss, thus smaller manes, in theory. Note I said Tsavo lions are said to have more testosterone," as in theorized, not fact. Such theory is derived from the seemingly greater aggresson and territoriality.
What do you mean by "see these results"? Are you refer to the excerpt posted? If so, the author published the conclusions of the study derived from statistical data taken by professionals in the field, why should one say the results are meaningless? I think we're actually on the same page, as you said, "that would specifically disprove this theory that testosterone is the main contributor to mane lentgth or color," but something is unclear in our points. I'll reword my initial point, the study shows that Asiatic lions have no low testosterone problem or genetic botteneck based on an actual study, and thus the twitter post is false. (06-16-2014, 10:29 PM)'tigerluver' Wrote: Regarding testosterone and mane, you are missing my point. Do not think greater testosterone increases hair, it is most probably the opposite. Greater testosterone is linked to hair loss, thus smaller manes, in theory. Note I said Tsavo lions are said to have more testosterone," as in theorized, not fact. Such theory is derived from the seemingly greater aggresson and territoriality.I asked to see the results. As in the actual numbers gotten from the captive lions and tigers, which ones were higher. Was it species specific or individual specific. Did the locations of the captive lions and tigers chance the testosterone levels? etc... Way to many questions to just take these alleged "results'' as fact. Your ''study" shows nothing more than excerpts on a few captive lions and tigers with no stud books, or results posted. It by no means can prove or disprove anything. Now about Manes length being shorter for higher testosterone. That is false, in serengetti lions the larger blacker manes, have a direct adaption to higher testosterone and physical health status, in gir or tsavo it doesn't matter. In captivity it is affected by climate same as in wild lions. So obviously the idea of testosterone levels affecting mane size or color is not the only factor.
The book is a secondary source to the study, and thus the excerpt doesn't have those details. One could dig up the citation of the study and go from there if that is such a problem. I don't have the book with me at the time so I can't give you the citation of the primary source, unfortunately. I can't seem to get my point across, it's getting off topic, and the mockery isn't too appreciated, so I'll stop here.
Regarding your second point, are you deriving that from Brown et al. 1991, or somewhere else?
Mockery?
I am simply asking for the results of the study which you are claiming disproves the twitter post. Here is the Serengetti research from Packer "Males with darker manes had higher testosterone levels," "Thus the lion’s mane appears to be a sexually selected signal by which a male advertises his quality to other lions. Our study also highlights the importance of temperature to lion ecology and behavior—which will become increasingly relevant in the face of global climate change: the Serengeti lions are already developing lighter and shorter manes than in the past. These findings were presented by Science magazine in a paper entitled “Sexual Selection, Temperature and the Lion’s Mane” by Peyton West and Craig Packer." http://lionresearch.org/ Read the entire article under "mane research"
Putting "study" and "results" in quotes when I brought up a legitmate source came off as mockery to me if that explains anything, but that's besides the point and I'll move on.
The primary source: http://www.iisc.ernet.in/currsci/nov10/articles19.htm (06-17-2014, 05:30 AM)'tigerluver' Wrote: Putting "study" and "results" in quotes when I brought up a legitmate source came off as mockery to me if that explains anything, but that's besides the point and I'll move on. Ok, thanks for posting the info. So looking at the study, they used 6 lions from 3 zoos. That is all, none wild and the animals where put under and electrically ejaculated which I am sure has its own effect on sperm production. Probably why 5+ tiger didn't ejaculate at all. This also is one study that is only captive and it also specifcally makes mention to another study where the indian lion has a higher deformity rate, lower sperm count etc... That is why one single study could never discredit another study of wild lions. like this one "T[font]he study revealed that the Serengeti group was genetically more heterozygous compared to the other two populations and the Asiatic lions were genetically monomorphic and showed significant decrease in motile spermatozoa per ejaculate and an increase in pleiomorphic spermatozoa to 66% (ref. 7). Based on these studies it was concluded that the Asiatic lion which has experienced a severe population bottleneck and has been inbreeding eversince is a highly endangered animal.[/font]" Not trying to be disrespectful, but why would this study mean more to you than the other? On to the 2nd part of the debate: You said "Do not think greater testosterone increases hair, it is most probably the opposite. Greater testosterone is linked to hair loss, thus smaller manes, in theory. Note I said Tsavo lions are said to have more testosterone," as in theorized, not fact. Such theory is derived from the seemingly greater aggresson and territoriality." So after I posted the link and quotes from Packer, what is your stance on this statement above?
This isn't proof one way or another, but I use it to show how large the differences can be between captive and wild animals.
 *This image is copyright of its original author
(06-17-2014, 09:29 PM)Pckts Wrote:(06-17-2014, 05:30 AM)'tigerluver' Wrote: Putting "study" and "results" in quotes when I brought up a legitmate source came off as mockery to me if that explains anything, but that's besides the point and I'll move on. Correct if I'm wrong, but according to this: "Wildt et al.7 based on the ejaculate characteristics, levels of LH and testosterone in serum and allozyme heterogeneity studies of lions from Sakkarbaug Zoo, concluded that the Asiatic lions are highly inbred and exhibit low genetic variation. However, the results of this study on 16 tigers and 11 lions from three zoos in India clearly indicate that a good majority of the animals do not show inbreeding depression effects." The more recent studies has lions from 3 programs, while the former has from only 1. That is why I favor the recent study. Dr. Packer's data shows that high testosterone leading to hair loss surely does not carry over from primates to lions, and obviously I accept that. Previously I was bringing uo "ifs" and theories, not intending them to be read as facts, just speculation. Nice evidence to prove otherwise Pckts, I think I've spent too much time on prehistoric felidae. (06-18-2014, 01:00 AM)'tigerluver' Wrote:[font]"lions namely an outbred population in the Serengeti National Park (Africa), a second group living in the Ngorongoro Crater (Africa) thought to have originated from the inbreeding of six to fifteen original founders and a third group of Asiatic lions from the Sakkarbaug Zoo (India). The study revealed that the Serengeti group was genetically more heterozygous compared to the other two populations and the Asiatic lions were genetically monomorphic and showed significant decrease in motile spermatozoa per ejaculate and an increase in pleiomorphic spermatozoa to 66% (ref. 7)[/font]"(06-17-2014, 09:29 PM)'Pckts' Wrote:(06-17-2014, 05:30 AM)'tigerluver' Wrote: Putting "study" and "results" in quotes when I brought up a legitmate source came off as mockery to me if that explains anything, but that's besides the point and I'll move on. Here the study compared two wild lions and two different locations and the 3rd Asiatic Lions where from the Sakkarbaug Zoo. But that is my point, Zoo lions showing completely different outcomes. And when compared to their wild counterparts, they appear to be inbred. Which is why wild animals should be keystone to any results that matter.
I agree wild animals are better than captive specimens, but the only functional data we have is of captive specimens. I wouldn't disregard data derived from captive specimens, as many great studies, such as those done by Dr. Christiansen, are based off of captive specimens.
Again, the Wildt et al. study only compared to lines of one zoo, and thus one lineage. The Shivaji studies uses three zoos and thus three lineages. So essentially we have this: out of 4 sample areas, 1 showed effects of inbreeding while 3 did not. In the available data, the majority rules. Furthermore, the Shivaji study is backed up by, "These results confirm the findings and conclusions of Singh et al.14 who, based on the observed genetic variation in Indian tigers and Asiatic lions, concluded that the genetic variability was a characteristic feature of these species and was not due to intensive inbreeding." Thus we have two sources favoring no inbreeding against one saying inbreeding is a problem, but this study essentially consisted of only one sample, and one sample is a much weaker representation of a population than three cited by the Shivaji study. Finally, see this, "In fact, the mean testosterone value of the Indian lions was very similar to that observed for the outbred lions of Serengeti7." This is the counterevidence to the Wildt et al. study, derived from 3 samples instead of 1. Here we have captive specimens showing similarities with wild, outbred specimens, favoring the validity of using captive specimens in this case.
The study consisted of actual Wild animals from two different locations and showed the difference between them and their captive counter parts.
In fact, the study consisted of 28 wild bred and captive lions compared to just 7 for the other. Other studies have shown the same thing "Lions in the Ngorongoro Crater form a small and naturally isolated population. In 1962, the Crater lions suffered an epizootic that reduced the population to nine females and one male; seven males apparently immigrated into the Crater in 1964-1965, and only one additional male has moved into the Crater in the past 45 years. By 1975, the population had recovered to 75–125 animals, but subsequently dropped to 29 in 1998 and 32 in 2003, and there has been considerable variance in the reproductive success of both sexes. The Crater was likely colonized by lions from the Serengeti ecosystem, and the Crater lions showed a significant lack of genetic diversity compared to the much larger Serengeti lion population by the 1980s. Computer simulations suggest that the Crater population may have passed through previous bottlenecks before 1962 and that the level of heterozygosity in the breeding population has likely been declining since the mid-1970s." "The Asiatic lions in the Gir Forest Sanctuary in the state of Gujarat, India, descend from a population totaling fewer than 250 individuals by the 19th century. The Gir lions show far lower levels of genetic diversity than the Crater lions, suggesting a drastic population bottleneck followed by even more intense inbreeding than in Ngorongoro. Many studies of inbreeding in livestock and laboratory animals have shown that reduced heterozygosity can adversely affect spermatogenesis, ovulation and perinatal mortality and morbidity. Comparing reproductive profiles of male lions from the Serengeti, Ngorongoro Crater and Gir Forest, sperm abnormalities were most common in the most inbred populations." The fact that gir lions show far lower levels of genetic diversity than Crater lions, which already are extremely low levels for genetic diversity is in itself telling that the girs look to be quite inbred. http://www.cbs.umn.edu/research/labs/lio...h/genetics
Semen and blood samples collected from 28 wild-caught and captive-bred lions from the Gir forest showed a high incidence (79%) of morphologically abnormal spermatozoa compared to free-ranging African lions, which is nearly always associated with infertility. The Gir lion population may have suffered a drastic population bottleneck or series of bottlenecks followed by inbreeding in their recent history.[8]
In the course of a later study, semen and blood samples were collected from seven lions in three Indian zoos. These samples showed high percentage of motile spermatozoa and low incidence of abnormal spermatozoa, thus implying that inbreeding depression had not affected these animals. The low genetic variability may be a feature of the species and not a result of inbreeding in recent times.[24] The RAPD techniques used in this population genetics research have been criticized as being imprecise and having major technical and analytical drawbacks.[25] 28 different Wild Caught and captive bred where used for the first study compared to just 7 lions all captive for the 2nd study you are using. "The RAPD techniques used in this population genetics research have been criticized as being imprecise and having major technical and analytical drawbacks.[25]"This was also written about the 2nd study
Also not only are these lions most likely inbred, their dna is almost identical to Barbary Lions as well. Most lions are actually very closely related and I believe there really should only be two sub species of lions. Gaute is far more knowledgable about this and he has provided tons of info on it. I am sure he will shed much more light on the subject.
Gaute wrote: "The new study of Dr Dubach, which presents the largest database on lion DNA, shows that lions from Ethiopia are NOT unique after all, and are better fit with those from the East Africa region. Lions of West Africa are closer related with Barbary lions (together with those of India) and these also weight " http://animalsversesanimals.yuku.com/top...6C3v7GfY08 |
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