speciation

But the giraffe turned out to be four species. From ScienceDaily: Evolutionary biologists have now discovered that the Pygmy Marmoset — the world’s smallest monkey — is not one species but two. Weighing in at just 100 grams — roughly the size of a large tomato — the insect-eating primate was first described scientifically in 1823 by German naturalist Johann Spix as Cebuella pygmaea, with a sub-species subsequently found. Now a team led by the University of Salford, using the latest techniques in genomics and phylogenetics, have established proof of two clades or branches of pygmy marmosets, that have diverged from one another around 2 — 3 million years ago. The study was restricted to monkeys in the Brazilian Amazon, Read More ›

Ah, start the day with fond memories. Most people who were kids in the mid-twentieth century grew up with the icons of horse evolution, starting with grubby little Eohippus and ending with Black Beauty. Of course, the story didn’t need to be true and as Jonathan Wells pointed out in Icons of Evolution, it wasn’t really true, at least not in a factual way. It was more the idea of evolution that was supposed to sink in for us. As CS Lewis has pointed out, Darwinian evolution was a great story, not necessarily to be confused with facts of nature. Meanwhile, at ScienceDaily: There are no such things as “wild” horses anymore. Research published in Science today overturns a long-held Read More ›

Theology can lead us to some weird places. From Evolution News and Science Today, in a continuing series on Adam and the Genome, As if on cue, science news today reports a remarkable discovery: cave art in Spain from upwards of 64,000 years ago, apparently by Neanderthals. The Wall Street Journal aptly summarizes the takeaway: Neanderthals, once considered the low-brows of human evolution, may have been among the world’s first artists, creating cave paintings long before modern humanity arrived on the scene… “Once considered”? This is timely because in the book Adam and the Genome, which we’ve been reviewing here, theistic evolutionist and biologist Dennis Venema discusses DNA that has been extracted from fossils of extinct members of the genus Read More ›

Culturally that’s a big one. From Carolyn Gramling at ScienceNews: The once-lengthy list of “definitely a dinosaur” features had already been dwindling over the past few decades thanks to new discoveries of close dino relatives such as Teleocrater. With an April 2017 report of Teleocrater’s skull depression (SN Online: 4/17/17), yet another feature was knocked off the list. … “I often get asked ‘what defines a dinosaur,’ ” says Randall Irmis, a paleontologist at the Natural History Museum of Utah in Salt Lake City. Ten to 15 years ago, scientists would list perhaps half a dozen features, he says. “The only one to still talk about is having a complete hole in the hip socket.” The abundance of recent discoveries Read More ›

From ScienceDaily: The number of recognized mammal species has increased over time from 4,631 species in 1993 to 5,416 in 2005, and now to 6,495 species. This total includes 96 species extinct within the last 500 years, and represents nearly a 20% increase in overall mammal diversity. The updated tabulation details 1,251 new species recognitions, at least 172 unions, and multiple major, higher-level changes, including an additional 88 genera and 14 newly recognized families. The new study documents a long-term global rate of about 25 species recognized per year, with the Neotropics (Central America, the Caribbean, and South America) as the region of greatest species density, followed closely by tropical regions of Africa, Asia, and the Indo-Pacific. Previous sporadic releases Read More ›

From Brian Owens at Nature: More than 98% of entomology papers contain so little species information on the insects being studied that they are essentially impossible to replicate, according to a survey of more than 550 articles published in 2016. aurence Packer, an entomologist at York University in Toronto, Canada, and his colleagues examined every paper published in 2016 in nine major entomology journals published by the United Kingdom’s Royal Entomological Society, the Entomological Society of America and the Entomological Society of Canada. Less than 2% of the papers included three key pieces of information: a description of how an insect was identified; evidence that biological samples had been documented and placed in a repository; and a reference to a Read More ›

Extinct species’ DNA suggests so, according to researchers. From Ewen Callaway at Nature: Scientists had assumed from fossil evidence that an ancient predecessor called the straight-tusked elephant (Paleoloxodon antiquus), which lived in European forests until around 100,000 years ago, was a close relative of Asian elephants. In fact, this ancient species is most closely related to African forest elephants, a genetic analysis now reveals. Even more surprising, living forest elephants in the Congo Basin are closer kin to the extinct species than they are to today’s African savannah-dwellers. And, together with newly announced genomes from ancient mammoths, the analysis also reveals that many different elephant and mammoth species interbred in the past. More. Speciation ain’t what it used to be. Read More ›

From ScienceDaily: Finding a new species is a rare event in easy-to-see and well-studied organisms like butterflies, especially if they inhabit well-explored areas such as Europe. Researchers have now discovered the previously unknown South-Russian blue using an array of modern research techniques. Furthermore, the new species was found to possess 46 chromosomes, just like a human, whereas its closest relative has 68 chromosomes. … Discovered by Vladimir Lukhtanov, entomologist and evolutionary biologist at the Zoological Institute in St. Petersburg, Russia, and Alexander Dantchenko, entomologist and chemist at the Moscow State University, the startling discovery was named South-Russian blue (Polyommatus australorossicus). It was found flying over the northern slopes of the Caucasus mountains in southern Russia. The study is published in Read More ›

It ranks right up there with “What is a species?” From Derek J. Skillings at Aeon: Evolution itself is meant to tell us which entities count as individuals. Because natural selection is the engine of evolution, Hull said, we need to account for individuality in terms of what is required for selection. At their most basic, evolutionary individuals are entities that vary among each other, their variability causes variations in fitness, and that variation and fitness is passed along to the next generation. These individuals are also often referred to as ‘units of selection’ because they are the unit upon which the process of natural selection operates. It is the selective pressure over evolutionary time that explains why organisms have Read More ›

At this point, is “species” just homage to Darwin’s Origin of Species? From ScienceDaily: The Atlantic sea nettle is one of the most common and well known jellyfish along the U.S. East Coast, especially in the Chesapeake Bay and Rehoboth Bay where they commonly sting swimmers in large numbers. Since it was described nearly 175 years ago, the jellyfish has been assumed to be a single species. The discovery that is was actually two distinct species, Gaffney said, was made possible by DNA sequencing techniques. “Before DNA came along, people in museums looked at organisms and counted spines and bristles, measured things, and sorted organisms by their physical characteristics in order to identify species,” Gaffney said. “In the case of Read More ›

From Jason G. Goldman at National Geographic: On November 20, 2013, the Sumatran Orangutan Conservation Programme got a call about an injured orangutan found in the mountainous region of Tapanuli. The orangatang had been fatally injured by humans. But Raya lives on as the representative member of a new orangutan species, Pongo tapanuliensis, or the Tapanuli orangutan—the rarest great ape species on the planet. At 800 members. Eventually, the scientists teamed up. Krützen’s group sequenced the entire genome of 37 wild orangutans throughout Sumatra and Borneo… The results, published November 2 in the journal Current Biology, show that Bornean orangutans, Sumatran orangutans, and the new species from Batang Toru comprise three distinct evolutionary lineages. Incredibly, the oldest lineage belongs to Read More ›

From ScienceDaily: A British enthusiasm for feeding birds may have caused UK great tits to have evolved longer beaks than their European counterparts, according to new research. … The specific gene sequences which had evolved in the British birds were found to closely match human genes known to determine face shape. There were also strong similarities with genes identified with beak shape in Darwin’s study of finches — one of the best-known examples of how physical traits have adapted to different environments in the wild. This led the researchers to think that great tit beaks were evolving by natural selection in British great tits, perhaps in response to the widespread use of bird feeders.Paper. (paywall) – Mirte Bosse, Lewis G. Read More ›

From Mikhail Tikhonov at The Scientist: More profoundly, microbial ecosystems are a strange world where many familiar concepts start to break down, including “species,” “fitness,” and maybe even “organism.” In our everyday experience, we are rarely in doubt whether a given creature is a fox or a rabbit. Further, it seems very easy to delineate where an “individual” ends, and its “environment” begins. Our ability to do so is often taken for granted, and underlies how we think about both ecology and evolution. Whether these assumptions remain adequate for microbes is, however, increasingly doubtful. … The issue of microbial species being ill-defined is a hot topic in the biological literature. In a recent paper in Physical Review E, I try Read More ›

Using “cutting edge DNA technology.” From ScienceDaily: Meladema coriacea is among Europe’s largest water beetles and has been considered common across the south of the continent and in North Africa since the early 19th century. But academics from the University of Plymouth and the Institute of Evolutionary Biology in Barcelona have now shown what was long thought to be one common species is actually two. Using DNA sequence data and detailed analysis of morphology, they have described a new species — Meladema lepidoptera — which appears virtually identical to Meladema coriacea at first glance, but is very divergent genetically. Meladema lepidoptera is restricted to Corsica, Sardinia, adjacent small islands and some areas of the Italian mainland, where it apparently occurs Read More ›

From Irby Lovette at All About Birds: Just a few steps from my desk here at the Cornell Lab of Ornithology, a tall cabinet holds 800 stuffed reminders of how difficult it can be to define the exact boundaries between bird species. These specimens are hybrids between what we now know as the Baltimore Oriole (which breeds in eastern North America) and Bullock’s Oriole (which breeds in the West). In between, Baltimore and Bullock’s Orioles meet up and interbreed in the cottonwood-lined corridor formed by the Platte River valley in Nebraska. In the 1950s, a team of Cornell scientists—motivated by then-new ideas about what hybridization might mean for how we define bird species—traveled along the Platte collecting specimens of orioles Read More ›