Research groups around the world are attempting to resurrect extinct species.
by Abby Olena
The only ever successful de-extinction was the birth of a baby bucardo (Capra pyrenaica pyrenaica)—a type of ibex specifically adapted to the Pyrenees Mountains in Europe—in 2003, though the young animal died soon after birth because its lungs did not function properly, according to BBC News. The clone was generated using frozen cells harvested in 1999 from the last bucardo, an old female that died in 2000. Now, the BBC reports that the Centre for Research and Food Technology of Aragon (CITA) in Zaragoza, Spain, will begin a new project to examine the burcado frozen cells to determine whether de-extinction efforts ought to be resurrected.
“At this moment, we are not initiating a bucardo recovery plan,” Alberto Fernandez-Arias, the head of the Service of Hunting, Fishing and Wetlands in the Aragon government, told the BBC. “We only want to know if Celia’s cells are still alive after having been maintained frozen during 14 years in liquid nitrogen.” Fernandez-Arias told the story of the 2003 bucardo de-extinction experiment in one of 25 talks at the TEDxDeExtinction meeting held this spring (March 15) in Washington, D.C…
A new species of wild cat has been identified in South America by using molecular markers, researchers claim. By comparing DNA sequences, the team revealed that two populations of tigrina in Brazil do not interbreed and are evolutionarily distinct.
Results also show the two populations have contrasting interactions with the closely related pampas cat and Geoffroy’s cat. The findings are published in the journal Current Biology.
There are at least seven species of small wild cat in the genus Leopardus in Central and South America, which are thought to have first colonised the region during the late Pliocene (2.5 - 3.5 million years ago).
A team of researchers led by Dr Eduardo Eizirik from the Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil collected samples of DNA from pampas cats (Leopardus colocolo) in the north of the country, Geoffroy’s cats (L. geoffroyi) from the south and two separate populations - north eastern and southern - of tigrina (L. tigrinus)…
About 54 million years ago, a semiaquatic deer-like creature headed into the water for good, giving rise to whales and their relatives. The newly sequenced genome of the minke whale, a baleen whale found worldwide, tells the story of how stressful this move to live underwater was.
An international team has decoded the genomes of four minke whales, a fin whale, a bottlenose dolphin, and a finless porpoise, comparing these cetaceans’ genes to the equivalent genes in other mammals. It found whale-specific mutations in genes important for the regulation of salt and of blood pressure and for antioxidants that get rid of charged oxygen molecules that can harm cells.
Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs
by Elizabeth Pennisi
The story of dogs began thousands of years ago, when gray wolves began sidling out of the shadows and into the company of humans. There’s little argument about that scenario—but plenty about when and where it took place, with the leading theories suggesting dogs were domesticated either in the Middle East or in East Asia. A study on page 871 draws on a new source of evidence, DNA from the fossils of ancient dogs and wolves, and comes to a third conclusion: Dogs originated in Europe, from a now-extinct branch of gray wolves.
The dogfight goes on. Based on the new study, “you will be hard-pressed to come up with a narrative about how dogs were not domesticated in Europe,” says Greger Larson, an evolutionary biologist at the University of Durham in the United Kingdom.
But some fans of the East Asia theory argue that the DNA examined, from cell organelles called mitochondria, cannot tell the whole story and that the analysis may be skewed because the ancient samples are primarily from Europe. “Critical observers will need more than mitochondrial DNA to be convinced,” says Stephen O’Brien, a geneticist at St. Petersburg State University in Russia, who says he is in neither dog origin camp…
The nematode wormCaenorhabditis elegans is an excellent model for understanding the genetic control of development and physiology. It was the first multicellular organism whose genome was completely sequenced.
Bats and Dolphins Evolved Echolocation in Same Way
by Elizabeth Pennisi
Dolphins and bats don’t have much in common, but they share a superpower: Both hunt their prey by emitting high-pitched sounds and listening for the echoes. Now, a study shows that this ability arose independently in each group of mammals from the same genetic mutations. The work suggests that evolution sometimes arrives at new traits through the same sequence of steps, even in very different animals. The research also implies that this convergent evolution is common—and hidden—within genomes, potentially complicating the task of deciphering some evolutionary relationships between organisms.
Nature is full of examples of convergent evolution, wherein very distantly related organisms wind up looking alike or having similar skills and traits: Birds, bats, and insects all have wings, for example. Biologists have assumed that these novelties were devised, on a genetic level, in fundamentally different ways. That was also the case for two kinds of bats and toothed whales, a group that includes dolphins and certain whales, that have converged on a specialized hunting strategy called echolocation. Until recently, biologists had thought that different genes drove each instance of echolocation and that the relevant proteins could change in innumerable ways to take on new functions…
Death by asexuality: IU biologists uncover new path for mutations to arise
"Contagious Asexuality" is Dominant in Sexual Genotypes
Univ. of Indiana media release
Ground-breaking new research from a team of evolutionary biologists at Indiana University shows for the first time how asexual lineages of a species are doomed not necessarily from a long, slow accumulation of new mutations, but rather from fast-paced gene conversion processes that simply unmask pre-existing deleterious recessive mutations.
Geneticists have long bet on the success of sexual reproduction over asexual reproduction based in a large part on the process known as Muller’s ratchet, the mechanism by which a genome accrues deleterious and irreversible mutations after the host organism has lost its ability to carry out the important gene-shuffling job of recombination.
The new work from the laboratory of IU Distinguished Professor of Biology Michael Lynch instead indicates that most deleterious DNA sequences contributing to the extinction process are actually present in the sexual ancestors, albeit in recessive form, and simply become exposed via fast-paced gene conversion and deletion processes that eliminate the fit genes from one of the parental chromosomes.
After sequencing the entire genomes of 11 sexual and 11 asexual genotypes of Daphnia pulex, a model organism for the study of reproduction that is more commonly known as the water flea, the team discovered that every asexual genotype shared common combinations of alleles for two different chromosomes transmitted by asexual males without recombination…
Gene for small horns lowers sexual fitness but boosts lifespan.
by Ewen Callaway
Alpha Red 78 — a ram with horns like elephant tusks — sired 95 lambs before he died at the ripe (for a ram) old age of nine. A gene with a role in horn growth explains his fertility and his longevity, finds a study of sheep on a remote Scottish isle. The work also explains how variation can persist in traits that offer big reproductive boosts.
Ample horns are a ram’s ticket to reproductive success. During the breeding season, males fight for access to females, and those with the largest horns win. But if big horns are a sexual asset, the genes underlying the trait should have become ubiquitous, says Susan Johnston, an evolutionary biologist at the University of Edinburgh, UK, who led the research. Yet some male sheep have short horns or none at all. “From an evolutionary perspective, it doesn’t really make sense,” Johnston says.
Johnston’s team turned to the sheep living on Hirta, an island 160 kilometres west of the Scottish mainland. The animals, a primitive breed called Soay (Ovis aries), are known for their diminutive size and their agility on cliffs…
Taxonomic Reassessment and Conservation Status of the Beaded Lizard, Heloderma horridum (Squamata: Helodermatidae) -
Heloderma alvarezi, H. charlesbogerti, H. exasperatum & H. horridum 
The beaded lizard (Heloderma horridum) and Gila monster (H. suspectum) are large, highly venomous, anguimorph lizards threatened by human persecution, habitat loss and degradation, and climate change. A recent DNA-based phylogenetic analysis of helodermatids (Douglas et al. 2010. Molecular Phylogenetics and Evolution 55: 153–167) suggests that the current infraspecific taxonomy (subspecies) of beaded lizards underestimates their biodiversity, and that species status for the various subspecies is warranted.
Those authors discussed “conservation phylogenetics,” which incorporates historical genetics in conservation decisions. Here, we reassess the taxonomy of beaded lizards utilizing the abovementioned molecular analysis, and incorporate morphology by performing a character mapping analysis. Furthermore, utilizing fossil-calibrated sequence divergence results, we explore beaded lizard diversification against a backdrop of the origin, diversification, and expansion of seasonally dry tropical forests (SDTFs) in Mexico and Guatemala. These forests are the primary biomes occupied by beaded lizards, and in Mesoamerica most are considered threatened, endangered, or extirpated…
The disease that sours oranges and leaves them half green, already ravaging citrus crops across the world, had reached the state’s storied groves. Mr. Kress, the president of Southern Gardens Citrus, in charge of two and a half million orange trees and a factory that squeezes juice for Tropicana and Florida’s Natural, sat in silence for several long moments.
“O.K.,” he said finally on that fall day in 2005, “let’s make a plan.”
In the years that followed, he and the 8,000 other Florida growers who supply most of the nation’s orange juice poured everything they had into fighting the disease they call citrus greening.
To slow the spread of the bacterium that causes the scourge, they chopped down hundreds of thousands of infected trees and sprayed an expanding array of pesticides on the winged insect that carries it. But the contagion could not be contained.
They scoured Central Florida’s half-million acres of emerald groves and sent search parties around the world to find a naturally immune tree that could serve as a new progenitor for a crop that has thrived in the state since its arrival, it is said, with Ponce de León. But such a tree did not exist…
For such tiny animals, Syllidae really get around.
These polychaete worms, most only a few millimeters long, are found from the intertidal to the deep sea. The over 200 species of Syllids, and potentially many more not yet recognized, are keeping some molecular biologists very busy. 133 species from 5 continents have DNA barcodes already, and our colleagues at the Moorea Biocode project just keep finding more, just waiting to be identified, or classified as new species.
700,000 Year Old Horse Becomes Oldest Animal To Have its Genome Sequenced
A genome sequence derived from a 700,000-year-old horse fossil (inset) sheds new light on equine evolution and confirms that Przewalski’s horse (pictured) is indeed genetically distinct from domesticated breeds.
by Gisela Telis
Scientists have sequenced the oldest genome to date—and shaken up the horse family tree in the process. Ancient DNA derived from a horse fossil that’s between 560,000 and 780,000 years old suggests that all living equids—members of the family that includes horses, donkeys, and zebras—shared a common ancestor that lived at least 4 million years ago, approximately 2 million years earlier than most previous estimates. The discovery offers new insights into equine evolution and raises the prospect of recovering and exploring older DNA than previously thought possible…
Scientists have long suspected that the killer whale, Orcinus orca, may actually be four different species or subspecies based of subtle differences in appearance and variations in behavior. The rarest of them all is known as type D. These fat-headed orcas, marked by tiny white patches around their eyes, were only recently observed in the wild, some 50 years after they were first identified in photographs from a mass stranding in New Zealand.
The skeleton of one of the type D whales that washed ashore in 1955 ended up at a museum in Wellington. In a new study, scientists analyzed DNA from the bones, showing, yes, type D is likely a distinct subspecies or species. The research, detailed in the journal Polar Biology, also suggests type D diverged from other killer whales about 390,000 years ago, making it the second oldest orca type…
We have many brightly-colored bird species, but few can compete with the North American tanagers. Molecular studies and other new research suggests the genus Piranga, including this Western Tanager (P. ludoviciana), are actually part of the cardinal Family (Cardinalidae), and not the tanager Family (Thraupidae) where they were originally placed.
The relationship is supported by their plumage: Piranga species are extensively red, orange or yellow - colors defined by carotinoid pigments - which is rarely seen in true tanagers but very common in the cardinal family. Despite the bright colors, they can often be hard to see as they spend much of their time high in the woodland canopy foraging on insects. Western Tanagers are a major consumer of the forestry crop pest Western Spruce Budworm (Choristoneura occidentalis).