Australian fairy-wren females prefer red


This video, recorded in Australia, is called IRES Red-backed Fairy-wren Research.

By Nidhi Subbaraman, NBC News, today:

Fooled by a Sharpie! Cheating birds steered to fidelity with red marker

Out in the Australian scrubland, scientists are using Sharpies to trick promiscuous female fairy-wrens from mating outside their subspecies, an “extra-marital” behavior that may be stalling evolution in its tracks.

Two groups of fairy-wrens live in Northwestern Australia: You can tells the males apart easily — one group has an orange band of feathers on their backs and the others are crimson red.

Females find partners within their subspecies — orange to orange and red to red — to nest and raise their brood with. But they also seek out other mates, aside from their “social” fathers-to-be, and that’s when they look for a bit of variety, Daniel Baldassarre and Michael Webster, ornithologists at Cornell University have found: They recorded how female birds from the orange group had a clear preference for red males outside their main relationships.

Not a natural red-back: A coat of non-toxic marker on an orange-backed fairy-wren (right) makes it as attractive to females as the naturally scarlet subspecies (left), photo by Daniel Baldassarre

Over two breeding seasons, the birders tracked 39 male fairy-wrens. They painted the feathers of one group of 13 red, coated another 13 in clear marker, tracked how the remaining 13 did with their natural orange back.

It turned out that just a coat of Sharpie-like coloring was enough to fool the females — orange-backed males with the PrismaColor Carmine Red dye job fathered twice more offspring than naturally orange males who lived in the same area, Baldassare and Webster found. Also, the redback males only attracted female birds that were cheating on their primary mate, they explain in the Wednesday issue of the Proceedings of the Royal Society B.

Was the red color irresistible to the females? Were they curious because it was new? “We don’t know that,” Webster told NBC News, that’s something they’re exploring in studies this year.

Webster says the orange and red subspecies of fairy-wren are in the process of diverging into two distinct species — something we know birds and mammals and reptiles do naturally over time, ever since Darwin observed his various species of finches on the Galapagos Islands.

When the orange-back females mate outside their species, they mix genetic material, stalling the usual course of divergent evolution.

For the Aussie fairy-wrens, this roadblock isn’t a big deal in itself. (And, the researchers won’t be trying to alter the birds’ behavior, chasing after orange birds with a red Sharpie any time soon.)

But this behavior does suggest that other related species of birds, mammals and reptiles that are being brought closer because of human factors could be “melding together into one species,” West said.

Daniel Baldassarre and Michael Webster are authors of “Experimental evidence that extra-pair mating drives asymmetrical introgression of a sexual trait.

See also here.

Extinct ape didn’t walk upright


This video says about itself:

The Ape That Took Over the World (Documentary)

14 Jan 2013

In 2001, scientists announced an amazing discovery: the oldest skull of a human ancestor ever found. The 3½ million year old fossil was remarkably complete, and unlike any previous fossil find. Its discovery – by a team led by Meave Leakey of the famous Leakey fossil-hunting family – has revolutionised our understanding of how humans evolved.

The great mystery of our evolution is how an ape could have evolved into the extraordinary creature that is a human being. There has never been another animal like us on the planet. And yet ten million years ago there was no sign that humans would take over the world. Instead the Earth was dominated by the apes. More than 50 different species of ape roamed the world – ten million years ago Earth really was the planet of the apes. Three million years later, most had vanished. In their place came something clearly related to the apes, but also completely different: human beings!

From the India Times:

Ancient Apes Didn’t Walk Upright

July 27, 2013, 3:46 pm IST

WASHINGTON: The ancient ape did not walk on two legs like humans do, as was previously believed, a new study has found, contradicting long-held assumptions.

The new study, led by University of Texas at Austin, found a 9- to 7-million-year-old ape from Italy did not, in fact, walk habitually on two legs. The findings refute a long body of evidence, suggesting that Oreopithecus had the capabilities for bipedal (moving on two legs) walking.

The study, published in the Journal of Human Evolution, confirms that anatomical features related to habitual upright, twolegged walking remain exclusively associated with humans and their fossil ancestors. “Our findings offer new insight into the Oreopithecus locomotor debate,” said anthropologists Gabrielle A Russo.

“While it’s certainly possible that Oreopithecus walked on two legs to some extent, as apes are known to employ short bouts of this activity, an increasing amount of anatomical evidence clearly demonstrates that it didn’t do so habitually,” said Russo.

The researchers analysed the fossil ape to see whether it possessed lower spine anatomy consistent with bipedal walking.

According to the findings, the anatomy of Oreopithecus lumbar vertebrae and sacrum is unlike that of humans, and more similar to apes, indicating that it is incompatible with the functional demands of walking upright as a human does.

Canadian fossil horse DNA discovery


This video is called Evolution Of The Horse.

From the BBC:

26 June 2013 Last updated at 17:46 GMT

Ancient horse bone yields oldest DNA sequence

By Jonathan Ball, BBC News

A fragment of a fossilised bone thought to be more than 700,000 years old has yielded the genome of an ancient relative of modern-day horses.

This predates all previous ancient DNA sequences by more than 500,000 years.

The study in the journal Nature

I have replaced the not working link to that Nature article on the BBC site with a link which does work.

was made possible because the bone was found preserved in Canadian permafrost following the animal’s demise.

The study also suggested that the ancestor of all equines existed around four million years ago.

A remnant of the long bone of an ancient horse was recovered from the Thistle Creek site, located in the west-central Yukon Territory of Canada.

Palaeontologists estimated that the horse had last roamed the region sometime between a half to three-quarters of a million years ago.

An initial analysis of the bone showed that despite previous periods of thawing during inter-glacial warm periods, it still harboured biological materials – connective tissue and blood-clotting proteins – that are normally absent from this type of ancient material.

DNA puzzle

And this finding was significant as study co-author of the paper, Dr Ludovic Orlando from the University of Copenhagen, explained to the BBC World Service programme Science in Action.

“We were really excited because it meant that the preservation was really good,” he told the BBC. …

From the resulting equine DNA fragments, they reconstructed a draft of its genome. Although the derived sequence data only covered around 70% of the entire genome, this was sufficient foundation for some revealing analyses.

The tell-tale presence of Y chromosome markers showed that the Thistle Creek bone had belonged to a male.

But the DNA also enabled them to reconstruct the evolutionary history of the larger Equus genus, which includes modern-day horses and zebras.

To do this, the scientists also determined the DNA sequence of a donkey, an ancient pre-domestication horse dating back around 43,000 years, five modern horses and a Przewalski’s horse, which possibly represents the last surviving truly wild horse population.

Family trees, based on similarity of the DNA sequences, revealed the relationships between these equine stable-mates and their longer evolutionary history.

Heirs and grazes

The Thistle Creek genome was reassuringly ancestral to the modern horses – positioned as it was at the base of the tree.

Geological dating evidence meant that the researchers could calibrate the rate of evolution in the different branches, and from this look back into the depths of the tree to approximate the age of the Equus genus ancestor – the forerunner to the donkey, zebra and horse.

Horse bone fragments DNA was extracted from pieces of the ancient bone

The results suggested it grazed the grasslands between 4 and 4.5 million years ago – twice as long ago as most previous estimates. …

Over the last two million years horses had experienced significant population expansions and collapses associated with climatic changes, and one collapse coincided with the date when the Thistle Creek and modern horses diverged. …

But would we recognise the Equus ancestor as a horse?

“Even if you look at the Przewalski horse, which has a divergence time of only about 50,000 years ago… and compare it to the domestic horse, you can already see differences,” observed Prof Willerslev.

“I would definitely say it would not look like a horse as we know it… but we would expect it to be a one-toed horse.”

See also here. And here. And here.

Galápagos Darwin’s finches evolution, new study


This video says about itself:

May 14, 2012

Darwin’s Finches in the Galapagos: Small Ground-finch, Large Ground-finch, Sharp-beaked Ground-finch (Vampire Finch), Common Cactus-finch, Small Tree-finch, Warbler finch.

From the Biological Journal of the Linnean Society in Britain:

Adaptive divergence in Darwin’s small ground finch (Geospiza fuliginosa): divergent selection along a cline

Article first published online: 14 JUNE 2013

Abstract

We examine here, in a single year (2005), phenotypic divergence along a 560-m elevation gradient in Darwin‘s small ground finch (Geospiza fuliginosa) in the Galápagos Islands. In this sample, four composite measures of phenotypic traits showed significant differences along the 18-km geographical cline extending from lowlands to highlands.

Compared with lowland birds, highland birds had larger and more pointed beaks, and thicker tarsi, but smaller feet and claws. Finches in an intervening agricultural zone had predominantly intermediate trait values. In a second, mark–recapture study we analyse selection on morphological traits among birds recaptured across years (2000–2005) in lowland and highland habitats.

Birds were more likely to survive in the highlands and during the wet season, as well as if they had large beaks and bodies. In addition, highland birds exhibited higher survival rates if they had small feet and pointed beaks – attributes common to highland birds as a whole. Lowland birds were more likely to survive if they possessed the opposite traits. Selection therefore reinforced existing morphological divergence, which appears to reflect local adaptation to differing resources during the predominantly drought-ridden conditions that characterized the 5-year study. Alternative explanations – including genetic drift, matching habitat choice, deformation by parasites, and the effects of wear – received little or no support.

Why Philornis downsi, the fly that “loves birds”, poses a risk to Finches on Galapagos Islands: here.

Sacred lotus closest to ancestor of flowering plants


This video from India says about itself:

Fruit and unripe seed pod of lotus or Nelumbo nucifera

Dec 19, 2012

Nelumbo nucifera, known by a number of names including Indian lotus, sacred lotus, bean of India, or simply lotus, is a plant in the monotypic family Nelumbonaceae. The Linnaean binomial Nelumbo nucifera (Gaertn.) is the currently recognized name for this species, which has been classified under the former names, Nelumbium speciosum (Willd.) and Nymphaea nelumbo, among others. Names other than Nelumbo nucifera (Gaertn.) are obsolete synonyms and should not be used in current works.

This plant is an aquatic perennial. Under favorable circumstances its seeds may remain viable for many years, with the oldest recorded lotus germination being from that of seeds 1,300 years old recovered from a dry lakebed in northeastern China.

A common misconception is referring to the lotus as a water lily (Nymphaea), an entirely different plant, as can be seen in the center of the flowers, which lack the structure that goes on to form the distinctive circular seed pod in the Nelumbo nucifera.

Native to Tropical Asian nations and Queensland, Australia, it is commonly cultivated in water gardens. It is also the national flower of India and Vietnam.

This footage is part of the professionally-shot broadcast stock footage archive of Wilderness Films India Ltd., the largest collection of imagery from South Asia.

From Big News Network (ANI), Saturday 11th May, 2013:

Sacred lotus bears closest resemblance to ancestor of flowering plants

A team of researchers has reported that they have sequenced the sacred lotus genome, and the results offer insight into the heart of some of its mysteries.

The sacred lotus (Nelumbo nucifera) is a symbol of spiritual purity and longevity. Its seeds can survive up to 1,300 years, its petals and leaves repel grime and water, and its flowers generate heat to attract pollinators.

The sequence reveals that of all the plants sequenced so far – and there are dozens – sacred lotus bears the closest resemblance to the ancestor of all eudicots, a broad category of flowering plants that includes apple, cabbage, cactus, coffee, cotton, grape, melon, peanut, poplar, soybean, sunflower, tobacco and tomato.

The plant lineage that includes the sacred lotus forms a separate branch of the eudicot family tree, and so lacks a signature triplication of the genome seen in most other members of this family, said University of Illinois plant biology and Institute for Genomic Biology professor Ray Ming, who led the analysis with Jane Shen-Miller, a plant and biology professor at the University of California at Los Angeles (who germinated a 1,300-year-old sacred lotus seed); and Shaohua Li, director of the Wuhan Botanical Garden at the Chinese Academy of Sciences.

“Whole-genome duplications – the doubling, tripling (or more) of an organism’s entire genetic endowment – are an important events in plant evolution,” Ming said.

Some of the duplicated genes retain their original structure and function, and so produce more of a given gene product – a protein, for example, he said. Some gradually adapt new forms to take on new functions. If those changes are beneficial, the genes persist; if they’re harmful, they disappear from the genome.

Many agricultural crops benefit from genome duplications, including banana, papaya, sugarcane, strawberry, watermelon and wheat, said Robert VanBuren, a graduate student in Ming’s lab and collaborator on the study.

Although it lacks the 100 million-year-old triplication of its genome seen in most other eudicots, sacred lotus experienced a separate, whole-genome duplication about 65 million years ago, the researchers found. A large proportion of the duplicated genes (about 40 percent) have been retained, they reported.

“A neat thing about the duplication is that we can look at the genes that were retained and see if they are in specific pathways,” VanBuren said.

The researchers found evidence that duplicated genes related to wax formation (which allows the plant to repel water and remain clean) and survival in a mineral-starved watery habitat were retained, for example.

By looking at changes in the duplicated genes, the researchers found that lotus has a slow mutation rate relative to other plants, Ming said.

These traits make lotus an ideal reference plant for the study of other eudicots, the researchers said.

The researchers reported their finding in the journal Genome Biology.

Family tree of all snakes and lizards


This video is called The Beauty of Snakes (Animal Planet Documentary).

From George Washington University in the USA:

Biologist Maps the Family Tree of All Known Snake and Lizard Groups

A George Washington University biologist and a team of researchers have created the first large-scale evolutionary family tree for every snake and lizard around the globe.

The findings were recently published in the journal BMC Evolutionary Biology. Alex Pyron, the Robert F. Griggs Assistant Professor of Biology in GW’s Columbian College of Arts and Sciences, along with researchers from the City University of New York and Arizona State University, detail the cataloging of 4,161 species of snakes and lizards, or squamates.

Squamates include all lizards and snakes found throughout the globe, including around 9,500 species on every continent except Antarctica, and found in most oceans,” said Dr. Pyron. “This is everything from cobras to garter snakes to tiny geckos to the Komodo Dragon to the Gila Monster. They range from tiny threadsnakes that can curl up on a dime to 10 feet monitor lizards and 30 foot pythons. They eat everything from ants to wildebeest.”

The evolutionary family tree, or phylogeny, includes all families and subfamilies and most genus and species groups, said Dr. Pyron. While there are gaps on some branches of the tree, the structure of the tree goes a long way toward fully mapping every genus and species group.

“It’s like building an incomplete family tree for your family, but with half of the ‘children’ sampled. You’re in it, but not your brother, one of your cousins is, but not another. However, because it’s so complete, we know where the missing relatives go because there’s no longer as much mystery as to how the missing species, or cousins, are related, with a few notable exceptions for some remaining species.

“This is also a community effort. We sequenced hundreds of these species ourselves but took thousands more from public databases, building on the work of others.”

Understanding how various snakes and lizards are connected to each other fills a major gap in knowledge, said Dr. Pyron, because before this, there were no single reference for how all lizards and snakes were related or what their classification was.

“A phylogeny and taxonomy is fundamental for all fields of biology that use lizards and snakes, to understand how to classify the species being studied, to interpret biological patterns in terms of relatedness, and even at a more basic level, to count how many species are in an area, for example, for conservation management purposes.”

This project has been in the works since 2008 with the last five years being the most intense. It was funded by the National Science Foundation Postdoctoral Research Fellowship in Biological Informatics.

The researchers used DNA sequencing technology to genotype, or identify, the DNA of thousands of lizards and snakes.

“We have laid down the structure of squamate relationships and yet this is still the beginning,” said Dr. Pyron. “As hundreds of new species are described every year from around the glove, this estimate of the squamate tree of life shows us what we do know, and more importantly, what we don’t know, and will hopefully spur even more research on the amazing diversity of lizards and snakes.”