speciation

The world’s simplest animal is trichoplax adhaerens. It is so simple that researchers wisely decided to forego the venerable Biological Species Concept that depends on an animal’s form (tricoplax doesn’t have much of a form) and just use genetics. But when evolutionary biologist Michael Eitel sequenced the genomes of several thousand of them, he was in for a surprise: A quarter of the genes were in the wrong spot or written backward. Instructions for similar proteins were spelled nearly 30 percent differently on average, and in some cases as much as 80 percent. The Hong Kong variety was missing 4 percent of its distant cousin’s genes and had its own share of genes unique to itself. Overall, the Hong Kong Read More ›

Earlier this month, 15 genomes were released. The Vertebrate Genomes Project aims to sequence every extant vertebrate species—there are about 66,000—and to make them of the highest possible value. … “What we thought was a ‘genome’ back [when G10K was launched] really wasn’t suitable for in-depth studies,” G10K cofounder David Haussler, a computational biologist at the University of California, Santa Cruz, tells Science. “I think we’ve reached a turning point.” Jef Akst, “Massive Animal Sequencing Effort Releases First Set of Genomes” at The Scientist Given how much genome mapping has done to debunk straightforward Darwinism, just from the genomes released to date, however complete, one can only guess at what all 66k would do. It was nice to see the Read More ›

The pythons invading Florida have been found to be Burmese-Indian hybrids, which means that they may be more adaptable than hoped. From ScienceDaily: The study also found that at least a few of the snakes in the invasive South Florida population are not 100 percent Burmese pythons. Instead, the genetic evidence shows at least 13 snakes out of about 400 studied are a cross between two separate species: Burmese pythons, which mostly inhabit wetlands, and Indian pythons, which prefer higher ground. The interbreeding between Burmese and Indian pythons probably took place before the animals became established in the South Florida environment, and may have given them greater adaptability in their new habitats. The South Florida pythons spring from a tangled Read More ›

Consider this item on the recent find of the remains of a girl from 90,000 years ago: The discovery of the first-known offspring of parents from two different hominin species took scientists by surprise. While evidence has been pointing to interbreeding among the ancestor species of modern humans, the direct link is being hailed as a significant finding.Kevin Kelleher, “A Neanderthal Mom and a Denisovan Dad: 90,000-Year-Old Bone Fragment Reveals Startling Human Hybrid” at Fortune “Species” “hybrid” “interbreeding”? What kind of talk is this about humans getting together? Yet it is everywhere. A reader wrote to ask, I’m not an expert on how ancient human species were defined, but I would assume that the authors aren’t using the biological species Read More ›

From ScienceDaily: Animals that have either migrated to or been introduced in Central Europe — such as the Asian bush mosquito or the Asian ladybeetle — feel extremely comfortable in their new homes due to changing climatic conditions. If these newcomers are genetically compatible with local species, they may crossbreed and produce hybrids, which can continue to evolve under local environmental conditions — a process that has been shown to have taken place during human evolution, between Homo sapiens and Neanderthals for example. New genes contributed by foreign species provide new genetic combinations that can be beneficial and are thus favoured by natural selection. According to hybrid swarm theory, interbreeding between hybrid species and parent species may then lead to Read More ›

From Sukanya Charuchandra at The Scientist: Two species of yeast, one of which is used in the biotechnology and food industries to make bioethanol and sourdough bread, while the other causes yeast infections, have been found to be one and the same, according to research published in PLOS Pathogens today (July 19). And, the researchers report, fungi from both settings are similarly resistant to antifungal drugs. The differences in the appearance of the sexual and asexual forms of the species and the underdeveloped nature of molecular methods were likely responsible for the varying names of the same organism. “It’s too common in fungi,” says Antonis Rokas, a comparative fungal genomics expert at Vanderbilt University who was not involved in this Read More ›

The “biological species concept” is yet another textbook dead zone. From ScienceDaily: Dr Addisu Mekonnen and colleagues at The University of Oslo, Norway, looked at the genetic diversity of the two populations of Bale monkeys. Analysis of mitochondrial DNA suggested strong genetic differences between the Bale monkeys who lived in continuous forests or fragmented forests. The researchers found that the populations of Bale monkeys were so different from each other that the Bale monkeys from fragmented forests were more similar to vervets and grivets than Bale monkeys from continuous forests. Dr Addisu Mekonnen, corresponding author of the study, explains: “Remarkably, our phylogenetic analysis showed that Bale monkeys in fragmented forests are more closely related to their sister species, vervets and Read More ›

Yesterday, PaV drew our attention to this story from Marlowe Hood at Phys.org: Sweeping gene survey reveals new facets of evolution Here’s another swatch from it, of interest: “another unexpected finding from the study—species have very clear genetic boundaries, and there’s nothing much in between. “If individuals are stars, then species are galaxies,” said Thaler. “They are compact clusters in the vastness of empty sequence space.” The absence of “in-between” species is something that also perplexed Darwin, he said.” More. If this replicates, it will do for textbook Darwinism what the Cambrian explosion did. Paper. See also: Startling Result–90% of Animals Less than 200 kya and Researchers: Cambrian explosion was not an explosion after all (It was just an intense Read More ›

From ScienceDaily: With individuals weighing in at more than 140 pounds, the critically endangered Chinese giant salamander is well known as the world’s largest amphibian. But researchers reporting in the journal Current Biology on May 21 now find that those giant salamanders aren’t one species, but five, and possibly as many as eight. The bad news as highlighted by another report appearing in the same issue is that all of the salamanders — once thought to occur widely across China — now face the imminent threat of extinction in the wild, due in no small part to demand for the amphibians as luxury food. … “We were not surprised to discover more than one species, as an earlier study suggested, Read More ›

About time too. From Jim Daley at The Scientist: The biological species concept, proposed by Ernst Mayr in the 1940s, defines a species as a group of individuals that can make fertile offspring only with one another, a notion he termed “reproductive isolation.” But that idea doesn’t jibe with Detwiler’s observations of monkeys in Gombe. By analyzing the mitochondrial DNA from epithelial cells found in 144 monkeys’ poop, she showed that red-tailed guenons (Cercopithecus ascanius) and blue guenons (C. mitis) have been mating and producing hybrid offspring for many generations. Using the sequencing data, she found that all of the monkeys in the park—hybrids, red-tails, and blues alike—can trace their ancestry back to an original group of female red-tailed guenons Read More ›

From Phoebe Weston at the Daily Mail, who offers a convenient bullet point format: Revealed: The worrying state of Earth’s species in numbers as scientists warn the sixth mass extinction is here and wildlife is in a ‘global crisis’ Two species of vertebrate, animals with a backbone, have gone extinct each year Currently more than a quarter of mammals are threatened with extinction There are an estimated 8.7 million plant and animal species on our planet About 86% of land species and 91% of sea species remain undiscovered Starting Saturday, a comprehensive, global appraisal of the damage, and what can be done to reverse it, will be conducted in Colombia More. The problem is, if we takes ecology seriously, how Read More ›

From ScienceDaily: Modern humans co-existed and interbred not only with Neanderthals, but also with another species of archaic humans, the mysterious Denisovans. Research now describes how, while developing a new genome-analysis method for comparing whole genomes between modern human and Denisovan populations, researchers unexpectedly discovered two distinct episodes of Denisovan genetic intermixing, or admixing, between the two. This suggests a more diverse genetic history than previously thought between the Denisovans and modern humans. … What is known about Denisovan ancestry comes from a single set of archaic human fossils found in the Altai mountains in Siberia. That individual’s genome was published in 2010, and other researchers quickly identified segments of Denisovan ancestry in several modern-day populations, most significantly with individuals Read More ›

What? Someone noticed? From Manchester University: A comprehensive new study looking at variations in Ichthyosaurus, a common British Jurassic ichthyosaur (sea-going reptile) also known as ‘Sea Dragons’, has provided important information into recognizing new fossil species. Professor Judy Massare (SUNY College at Brockport, NY, USA) and Dean Lomax (The University of Manchester) have studied hundreds of specimens of Ichthyosaurus. After their latest research project the pair urge caution in naming new fossil species on the basis of just a few fragmentary or isolated remains. For their research Prof Massare and Lomax focused on one particular part of the Ichthyosaurus skeleton, the hindfin (or back paddle). The purpose was to evaluate the different forms among the six-known species of Ichthyosaurus. They Read More ›