The migratory locust is polyphenic. It has a solitary phase and a gregarious phase. This is a type of polymorphism where a single genotype produces two or more phenotypes. During development, an environmental factor causes a switch from one morph to another.
For the migratory locust, the switch is caused by population density. As the density of the population increases the locust transforms from the solitary phase to the gregarious phase, with intermediate phases.
The colour and size of the migratory locust changes according to its phase and its age. "Gregarious larvae" have a yellow to orange covering with black spots. "Solitary larvae" are green or brown. The "gregarious adult" is brownish with yellow, the latter colour becoming more intense and extensive on maturation. The "solitary adult" is brown with varying extent of green colour depending on the colour of the vegetation. "Gregarious adults" vary in size between 40 and 60 mm according to the sex. They are smaller than the solitary adults.
Kow Swamp archaeological site
The Kow Swamp archaeological site is on the eastern side of Kow Swamp in northern Victoria. A number of Pleistocene burials have been found in a sand dune, known as a lunette. Archaeologist Alan Thorne dug up the skeletons of more than 22 people between 1968 and 1972.
The discovery of human remains included skulls which appeared to be 'pre-sapiens', that is, earlier than modern man. Later studies did not confirm this.
Kow Swamp is named for an Aboriginal word, "Ghow", from the Yorta Yorta language. It means white gypsum soil which is found in the area. Kow Swamp is now a lake used to store irrigation water. It is 15 kilometres in circumference and about 3 metres deep. It was once a low lying swamp which only filled when the Murray River was in flood or running at high levels.
Australian aborigines have lived at Kow Swamp. There are canoe trees where the bark has been taken from the tree to make a canoe. There are also middens, which are rubbish heaps with evidence of what people ate. Early European settlers described an Aboriginal ceremonial site on the north side of the swamp. In 1925 part of a skull was found on the west side of the swamp during digging works. It was called the "Cohuna Cranium". The editor of the local newspaper "Cohuna Farmers Weekly" notified authorities and the importance of the discovery was realised. In the 1960s, Alan Thorne also found an ancient bone in the collection at the Museum of Victoria, and traced the find spot to Kow Swamp. Archaeological excavations took place between 1968 and 1972 by Thorne for the Australian National University in Canberra. Further remains were found around the swamp by a local person, Gordon Spark. By 1972 the remains of at least forty individuals had been excavated and studied. These discoveries helped prove the wide range of Aboriginal genetic history. They have been used to show that there were different waves of immigrants to Australia before European discovery.
Radiocarbon dating has shown that most of the burials took place between 13,000 and 10,000 years ago. The youngest burial was about 6,500 years old. Optically stimulated luminesence (OSL) dating in 2003 showed the burials were between 22,000 and 19,000 years old. However, these dates have been questioned due to the difficulty of making sure the dated sand is the same age as the actual burials. Dating research on bones from other sites in the region such as Nacurrie and Coobool Creek, support the 13,000 to 9,000 date range for Kow Swamp.
At first the skulls from Kow Swamp were thought to be from "Homo erectus", not modern "Homo sapiens". Thorne believed that it showed "the survival of "Homo erectus" features in Australia until as recently as 10,000 years ago". However, Donald Brothwell disagreed and said size and shape of the skulls at Kow Swamp had been caused by artificial cranial deformation.
The size and shape of the skulls are different from modern Aboriginal skulls. They are also different to Pleistocene remains found at Lake Mungo and Keilor. These differences have been used to suggest that different people came to Australia at different times in the past. However, more recent studies do not support this theory. Most of the skulls were in small fragments, and only two were reasonably complete.
Aboriginal community groups have asked for the human remains from Kow Swamp be returned from Australian and overseas museum collections. The Kow Swamp skeletons were returned to the area and reburied. Casts of some of the Kow Swamp skulls are held by the Archaeology and Human Sciences department at the Australian National University. Some casts are also at London Natural History Museum and other institutions.
Toni Basil
Mary Antoinette Hoole (stage name Toni Basil; September 22, 1943) is an American singer-songwriter, dancer and actress. She is best known by the 1982 hit single "Mickey". In addition, she has performed in many movies. Basil was born in Philadelphia.
Polyphenism
Polyphenism is a kind of polymorphism where different forms of an animal are caused a single genotype. The animal inherits the capability, but the environment determines which form develops. This contrasts with genetic polymorphism, where each morph (form) inherits a slightly different genome.
Polyphenism occurs when the animal inherits a developmental switch. The switch is sensitive to some environmental cue or trigger. For example, the sex of crocodiles is determined by the prevailing temperature. Their gender is a polyphenic trait, and is not determined by the usual sex linkage.
The caste system of social insects is the division of labor between genetically identical individuals. Polyphenism determines whether larvae develop into queens, workers, and in some cases soldiers. In the case of the ant, "P. morrisi", an embryo must develop under certain temperature and photoperiod conditions in order to become a reproductively-active queen. This allows for control of the mating season, but like sex determination, limits the spread of the species into certain climates.
In bees, "royal jelly" provided by worker bees causes a larva to become a queen. Royal jelly is only produced when the queen is aging or has died.
Polyphenic pigmentation is adaptive for species which reproduce several times a year. Different pigment patterns provide camouflage throughout the seasons, and alter heat retention as temperatures change. Because insects cease growth and development after they are adults, their pigment pattern is set in adulthood. In the case of the peppered moth, "Biston betularia", the caterpillars are polyphenic. Their trigger is switched by the colour of the plants they are eating: see "this".
Sarah Kofman
Sarah Kofman (September 14, 1934 - October 15, 1994) was a French philosopher and writer. She wrote many books about many topics. She committed suicide at age 60.
Antonov An-26
The Antonov An-26 is soviet built twin-engine transport aircraft. It is used by both airlines and air forces. It is a short takeoff and landing aircraft.
It is built under licence in China like "Y-7H". An-26 is a modernized variant of An-24.
Mount Unapproachable
Mount Unapproachable is a mountain in the southwest of the Northern Territory, Australia. It is on the northern side of Lake Neale. It is about above sea level. The area is far apart from other towns. The nearest towns are Kaltukatjara (116 km away), Kintore (135 km away) and Yulara (138 km away). The mountain is mostly made of sandstone.
The mountain was named by explorer Ernest Giles in 1872. Giles was on an expedition to find a way across the desert from east to west. He had just found and named Lake Amadeus. He could see the mountain rising to the west, and hoped to find water there. But, he was unable to get to the mountain because his path was blocked by the lake. Giles in fact over-estimated the size of Lake Amadeus and missed the bridge of land between Amadeus and Lake Neale.