Journal+Articles

1. Parthenogenesis in Komodo Dragons. NATURE|Vol 444|21/28 December 2006. 2. This article is about a study of two Komodo dragons that were able to reproduce by parthenogenesis. Parthenogenesis is when a lack of males in a population causes the females to reproduce asexually. Parthenogenesis was previously unknown to occur in Komodo dragons. The first case of Parthenogenesis occurred in the Chester Zoo, UK with a Komodo dragon named Flora. She had never been kept with a male Komodo dragon but produced a clutch of 25 eggs. 11 of those 25 eggs were viable. 3 of the eggs collapsed during the early stages of incubation and were used to provide embryonic material for genetic fingerprinting. When the article was written the remaining eggs were developing normally and were expected to hatch in January of 2007. The second case of parthenogenesis in Komodo dragons occurred in the London Zoo, UK with a Komodo dragon named Sungai. Sungai had been in contact with a male 2.5 years previous to her production of a clutch of 22 eggs, with 4 of them viable. The eggs hatched 7.5 months later and the young were healthy. A second clutch of eggs was later laid by Sungai after she had mated with a male. Only one of these eggs hatched. After the parentage of the eggs was analyzed it was determined that all of the offspring were parthenogens. The offspring were homozygous, although they were not identical clones. Because of this Parthenogenesis was confirmed by exclusion. Because Sungai resumed sexual reproduction, it was determined that parthenogenesis is not a fixed reproductive trait and that asexual reproduction among Komodo dragons most likely only occurs when necessary. Only about 70 vertebrate species have been reported to have parthenogenesis. Parthenogenesis was unexpected to occur in such large reptiles as Komodo dragons. It has been reported in captive snakes and in one other species of monitor lizard (//Varanus panoptes//). Parthenogenesis could be a problem for the genetic management of Komodo dragons. Captive breeding is an important part of conservation; this occurrence could mean that the studbook records are inaccurate. Another concern is the instantaneous homozygosity of the genome, because of the risks of interbreeding. However, the 4 Komodo dragon parthenogens in the London Zoo are healthy and developing normally. Another negative effect is that parthenogenesis can bias the sexual ratio. In the //Varanus// species the females have dissimilar chromosomes (Z and W) and the parthenogenesis only produces homozygous (ZZ of WW) organisms and no females because of this. It is thought that parthenogenesis is an adaptive trait because the offspring are always viable males. There are currently less 4,000 Komodo dragons in the wild and less that 1,000 of them are female. 3. ** Genetic Fingerprinting: ** A technique to distinguish between individuals of the same species using only samples of their DNA. ** Reproductive Plasticity: ** ** Genetic Load: ** the extent to which a p opulation deviates from the theoretically fittest genetic constitution ** Viable: ** Able to germinate 4. This applies to my goals because it is a study of the evolustion of Komodo dragons and it was done through the use of a journal article.

 Lizard Questions   1. ** Standby  ** - One that is held in reserve ready for use ** Smorgasbord  ** - an extensive array or variety ** Species  ** - a class of individuals having common attributes and designated by a common name ** Lineage  ** - descent in a line from a common progenitor ** Herpetologist  ** - A person who studies the branch of zoology dealing with reptiles and amphibians ** Grueling  ** - trying or taxing to the point of exhaustion ** Delicacy  ** - something pleasing to eat that is considered rare or luxurious ** Parthenogenesis  ** - reproduction by development of an unfertilized usually female gamete that occurs especially among lower plants and invertebrate animals ** Hybrid  ** - an offspring of two animals or plants of different races, breeds, varieties, species, or genera  2. Cloning is a good solution to for a species in an adverse environment, when there is pollution, or over hunting because it allows the species to propagate quickly and survive until there are better living conditions. It wouldn’t be necessary or useful in other situations because then the species would overpopulate and there wouldn’t be enough food, a species need to reproduce sexually so that there can be genetic variation and thus further evolve and change the species for its benefit.  3. The scientist was intrigued by the tank of reptiles because it was something that he hadn’t seen before or herd of and he was curious and wanted to investigate in case it was something new. His friend dropped everything for much the same reason.  4. Scientific knowledge is the official, catalogued knowledge of the world. Local knowledge is the common, spoken and known knowledge of an area, about an area. I suppose about 65% of the worlds knowledge is catalogued.  5. Academics decide what knowledge is worth knowing based on how useful it is and interested they are in it. They find this knowledge through research, and communicating with other scientists, and sometimes by accident. <span style="line-height: 150%; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1; text-indent: -0.25in;"> 6. It is important for scientist to catalogue species so that they know what animals there are and so that other scientists can know of their discoveries and not “rediscover” them. <span style="line-height: 150%; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1; text-indent: -0.25in;"> 7. I don’t think it would have occurred to anyone in South Vietnam to alert scientists of these lizards because they see them every day so they aren’t something new or strange and there is no reason to tell scientists about it. <span style="line-height: 150%; margin: 0in 0in 0pt 0.5in; mso-list: l0 level1 lfo1; text-indent: -0.25in;"> 8. People use local knowledge to know what animals are good to eat and what animals are dangerous, even though they don’t record it. <span style="line-height: 150%; margin: 0in 0in 10pt 0.5in; mso-list: l0 level1 lfo1; text-indent: -0.25in;"> 9. Scientists might make use of local knowledge by learning more about animals that they already know exist, because people will know a lot about the animals that they live around and about the place that they live. Historians can learn about local myths, legends, and stories from the local people.