New Definition of 'Species' Could Aid Species Identification

Aug 24, 2006

Scientists at Texas Tech University argue that defining mammalian species based on genetics will result in the recognition of many more species than previously thought present. This has profound implications for our knowledge of biodiversity and issues based on it, such as conservation, ecology, and understanding evolution. Their study is published in the latest Journal of Mammalogy.

The classical definition of species was proposed by Ernst Mayr in 1942, defining it as reproductively isolated groups of organisms. According to this study, the problem with applying this concept is that it is hard to observe mating and to know whether there is interbreeding between populations and thus creation of hybrid species. Traditionally, species have been recognized based on physical characteristics, although it has been assumed that species differences are inherited and thereby reflect genetic differences.

Study researchers Robert Baker and Robert Bradley define “species” based on genetic data. The new definition distinguishes species that are genetically isolated from one another. Baker and Bradley’s genetic species concept also differs from the phylogenetic species concept proposed by Joel Cracraft in 1989 by emphasizing genetic isolation and protection of the integrity of the gene pool.

New molecular techniques for sequencing genes provide far greater resolution than was previously available. They also allow researchers to quantify problems in understanding the process of speciation. Using genetic data, it is now possible to distinguish species that are morphologically similar—those known as cryptic species. It is also possible to identify species that hybridize but have gene pools that are protected from one another.

The result of using genetic data is that species can be identified that cannot be distinguished using other methods. Baker and Bradley point out that this means there are doubtless many more species than previously thought. They hypothesize that there are 2,000 more mammalian species than are currently recognized.

According to the authors, this means that we will need to rethink the nature of speciation in mammals, barriers that evolve to produce genetic isolation between species, and how diverse mammals are, as well as other species-based issues such as those relating to conservation and zoonoses, communicable diseases from animals to humans.

To read the entire study, click here.

Source: Alliance Communications Group

Explore further: Japan to continue scientific whaling in Pacific: reports

add to favorites email to friend print save as pdf

Related Stories

Diverse gene pool critical for tigers' survival

4 hours ago

(Phys.org) —New research by Stanford scholars shows that increasing genetic diversity among the 3,000 or so tigers left on the planet is the key to their survival as a species.

Beneficial organisms react differently to parasite drug

Apr 14, 2014

The substance ivermectin has been used for more than thirty years all over the world to combat parasites like roundworms, lice and mites in humans, livestock and pets. The active ingredient belongs to the chemical group of ...

The science of anatomy is undergoing a revival

Apr 10, 2014

Only two decades ago, when I was starting my PhD studies at the University of California in Berkeley, there was talk about the death of anatomy as a research subject. That hasn't happened. Instead the science ...

One or two? How to decide how many species you have got

Apr 02, 2014

It is often difficult to decide whether two animals belong to the same or two distinct species. This can be especially challenging for animals which externally look very similar. In a recent study, published ...

Dingo a distinct species, study says

Apr 01, 2014

(Phys.org) —The dingo has been classified as a distinct Australian animal following research that sheds new light on its defining physical characteristics.

Legume research uncovers nitrogen uptake genes

Apr 01, 2014

(Phys.org) —Increased nitrogen-use efficiency of plants and an associated reduced need for nitrogen-based fertilisers may be a step closer following University of Adelaide research on legumes.

Recommended for you

Plants with dormant seeds give rise to more species

8 hours ago

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

11 hours ago

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Plants with dormant seeds give rise to more species

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...