Evolution: What the lizard or the Egg came first?

0
505

Biologists at the University of Sydney, have observed for the first time that an Australian lays smooth lizard first eggs and, later, a living young animal brings to the world. Sounds bizarre, but it makes a lot of sense.

First of all, the Australian native lizard laid three eggs, and then weeks later brought the smooth lizard Saiphos equalis also a living young animal from the same pregnancy. This is the first Time that such an event was documented in a single throw of vertebrate animal-young animals.

Researcher Camilla Whittington, with another smooth echsenart, a Stachelskink

Two-Fold Reproductive Ability

“It’s a very unusual discovery,” said Camilla Whittington of the “School of Life and Environmental Sciences” at the University of Sydney. The observation is published this week in Biology Letters, together with a detailed microscopy of the Eiabdeckungen.

The Skink species originates from the East coast of Australia. In the Northern high country of New South Wales, the animals normally living young animals to the world, but in and around Sydney, living animals lay eggs. Smooth lizards belong to the rare species of vertebrates, in which both reproductive variants, watch – where some individuals lay eggs, and other live Young. But, so far, has never been observed that vertebrate animals do both in a litter.

The smooth lizard Saiphos equalis remains flexible through its mixed reproductive ability

Hedge against environmental fluctuations

According to Whittington, it is in vertebrates at least 150 evolutionary Transitions of eggs, legend to viviparous. “The first vertebrate animals laid eggs, but in the course of Evolution some species have developed the ability to carry embryos longer in the body. We generally only think of humans and other mammals, which give birth to live. But there are also many species of reptiles that do that.” Both methods have their advantages and disadvantages.

“In the context of the evolutionary biology of animals, which can switch between Laying eggs and live birth are able to insure their Offspring according to environmental conditions,” the biologist Whittington.


  • The Cabinet of curiosities of the reptiles

    Animal Camouflage

    Well, where is the mini lizard? With its green color, this small, grass-green day Gecko barely differs from the sheet. This genus has no eyelids. In the course of Evolution, the upper and lower eyelids are axis to a transparent membrane. Usually you meet these diurnal animals on the Islands of the Indian ocean or Madagascar.


  • The Cabinet of curiosities of the reptiles

    Please don’t touch!

    This Lizard lives up to its name: The entire body is covered with thorns. The thorny devil Lizard is exclusively located in Australia. The life in the drought, they adapted perfectly, because the grooves in the rain, transporting the body, and condensation directly into the mouth.


  • The Cabinet of curiosities of the reptiles

    Not my collar size!

    Tried the frilled lizard, now when you set up your flap of skin on the neck. She threatens to enemies, predators or rivals. Up to 30 centimeters in diameter, and the neck ruff. Collar lizards belong to the agamid. They live exclusively in Australia and new Guinea.


  • The Cabinet of curiosities of the reptiles

    A small Sensation

    Brookesia micra is the smallest known reptile in the world. Due to its tiny length of 23 to 29 mm, and its brown coloration, it falls to the forest floor. The tiny chameleon lives on an island in the North of Madagascar. About his life almost nothing is known yet.


  • The Cabinet of curiosities of the reptiles

    Colourful Long Nose

    A representative from the species-rich Madagascar: Panther chameleons are one of the most colorful of its kind. The color spectrum ranges from grey through Green to Pink and Purple. Characteristic of the entire back-running ridge that ends in an extension of the nose.


  • The Cabinet of curiosities of the reptiles

    Dwarves-Triceratops

    Slightly smaller than its dinosaur counterpart, the three-horned chameleon. With 38 centimeters in body length the males of this species are considerably larger than many of its Relatives. The three-horned chameleon in the rain in the mountains of East Africa home forests.


  • The Cabinet of curiosities of the reptiles

    Seaweed diving in the Galapagos

    A truly good a diver for the Marine iguana on the Galapagos Islands. Up to 30 minutes, she goes under water in search of food. In the process, your heartbeat slows down to ten beats per Minute. Their skin is mostly dark, in order for it to warm up after the bath in the cold water as quickly as possible.


  • The Cabinet of curiosities of the reptiles

    Giant Dragon

    Up to 70 kilograms, the largest living Lizard on the scale! Even deer and wild boar are not the Komodo dragon as prey. His secret weapon is the poisonous saliva, which can reduce blood clotting, and shock. The Komodo dragon lives exclusively on the smaller Islands of Indonesia.


  • The Cabinet of curiosities of the reptiles

    Green Air Snake

    The Green tree Python is like living with a view. In up to 25 meters in height, the snake wraps itself around tree Branches. So hidden she lies in wait for potential prey. The striking green animals live in the North of Australia and on new Guinea.


  • The Cabinet of curiosities of the reptiles

    Small head with a big impact

    An impressive example of how the outer appearance can be deceiving. The skin in the jaw area of the egg-eating snake is three to four times stretchy. The just thumb thick snake. even chicken eggs to eat The entire process will be.only farmers in sub-Saharan Africa, where the egg-eating snake is on the prowl


  • The Cabinet of curiosities of the reptiles

    Awesome quirky!

    At first glance, the appearance of this fringe seems to turtle everything other than intended. However, the fringes on the body are awesome: you are in the fresh water of South America living turtle under water appears to be almost invisible. Since each chameleon would envy!

    Author: Valentin Betz