Mammoths Meted Beyond Species Boundaries

A new study suggested that different species of mammoths meted in North America. A new research study on the DNA structure of the mammoth genome suggests that they meted beyond their species boundaries. Several species of mammoth are thought to have roamed across the North American physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring.

A species can be defined as a group of similar animals that can successfully breed and produce fertile offspring. By using differences in the size and shape of their fossilized teeth, a number of North American mammoth species have been identified. But some scientists are not confident this method of species categorization tells the whole story.

North American mammoths such as the Colombian mammoth and the Wooly Mammoths were historically thought to originate from two separate primitive species. However, the latest DNA analysis agrees with a more recent idea that all North American mammoths originated from a single primitive species, the Steppe Mammoth. So, while mammoths clearly method of differences in their physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring. 

Despite this apparent adaptability, which should surely be a recipe for success, mammoths disappeared from the face of Earth 10,000 years ago. 

As well as challenging the classic method of defining a species, scientists believe the findings of this study are just the start of understanding mammoth evolutionary history. Techniques to extract and analyses ancient DNA have undergone a tremendous improvement in recent years and as these technologies continue to improve we can expect further breakthroughs.

New Models Predicting where to Find Fossils

An international team of scientists have developed a way help locate fossils of long-extinct animals.The models were developed for Australia but the researchers provide guideline on how to apply their approach to assist fossil hunting in other continents.

The research team made use of modelling techniques commonly used in ecology. They modeled past distribution of species, the geological suitability of fossil preservation and the likelihood of fossil discovery in the field. They applied their techniques to a range of Australian megafauna that became extinct over the last 50,000 years, such as the giant terror bird Genyornis, the rhino-sized wombat Diproton and the marsupial lion.

To produce the species distribution models of these long-extinct animals, the researchers used 'hindcasted global circulation models' to provide predicted temperature and rainfall for the deep  past and matched this with the estimated ages of the fossils.

In the model they build a probability map for each of these layer -- the species distribution, the right sort of geological conditions for fossil formation and the ease of discovery. They combined each of these for an overall. The methods predict potential fossil locations across an entire continent which is useful to identify potential fossil areas far from already known sites. It's good exploration filter, after which remote-sensing approaches and fine-scale expert knowledge could complement the search.

The model showed areas south of Lake Eyre and weest of Lake Torrens in South Australia and a large area around Shark Bay, Western Australia and other areas in south-western Australia with a high potential to yield new megafauna fossils.

Source: PLOS ONE