New pygmy seahorse species discovery


This 15 August 2018 video says about itself:

This New Species of Pygmy Seahorse is the Size of a Lentil | Nat Geo Wild

This pygmy seahorse is tiny—the size of a grain of rice. Researchers recently discovered that the colorful animal is a distinct species. Its name is Hippocampus japapigu, Latin for “Japan pig” seahorse, as some believe it resembles a baby pig.

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Messel, Germany Eocene animal fossils


This 17 July 2018 video says about itself:

The Mystery of the Eocene’s Lethal Lake

In 1800s, miners began working in exposed deposits of mud near the town of Messel, Germany. They were extracting oil from the rock and along with the oil, they found beautifully preserved fossils of animals from the Eocene. What happened to these Eocene animals? And why were their remains so exquisitely preserved?

Two additional notes!

-At 00:56, we incorrectly labelled a Darwinius fossil as Thaumaturus. Thaumaturus was a fish and the fossil we show is definitely not a fish.

-Also, an additional image credit is required: Dmitry Bogdanov illustrated the fish we used to show scavengers.

Peppered moths and evolution, new study


This 1 June 2016 video says about itself:

Insect icon Peppered moth mystery solved: BBC News

From the University of Exeter in England:

Study confirms truth behind ‘Darwin‘s moth’

August 17, 2018

Scientists have revisited — and confirmed — one of the most famous textbook examples of evolution in action.

They showed that differences in the survival of pale and dark forms of the peppered moth (Biston betularia) are explained by how well camouflaged the moths are to birds in clean and polluted woodland.

“Industrial melanism” — the prevalence of darker varieties of animals in polluted areas — and the peppered moth provided a crucial early example supporting Darwin‘s theory of evolution by natural selection, and has been a battleground between evolutionary biologists and creationists for decades.

The common pale form of the moth is camouflaged against lichen growing on tree bark. During the Industrial Revolution — when pollution killed lichen and bark was darkened by soot — a darker-winged form emerged in the UK.

Later, clean air legislation reduced soot levels and allowed lichen to recover — causing a resurgence of pale peppered moths.

The example has been well supported by many studies, but nobody had ever tested how well camouflaged the moths were to the vision of their key predators — birds — and how their camouflage directly influenced survival.

Now scientists at the University of Exeter have shown that, to the vision of birds, pale moths are indeed more camouflaged against lichen-covered trees than dark moths — making pale moths less likely to be eaten by birds in unpolluted woodland and giving them an evolutionary advantage.

“This is one of the most iconic examples of evolution, used in biology textbooks around the world, yet fiercely attacked by creationists seeking to discredit evolution”, said Professor Martin Stevens, of the Centre for Ecology and Conservation on the University of Exeter’s Penryn Campus in Cornwall.

“Remarkably, no previous study has quantified the camouflage of peppered moths, or related this to survival against predators in controlled experiments.

“Using digital image analysis to simulate bird vision and field experiments in British woodland, we compared how easily birds can see pale and darker moths, and ultimately determine their predation risk.

“Our findings confirm the conventional story put forward by early evolutionary biologists — that changes in the frequency of dark and pale peppered moths were driven by changes in pollution and camouflage.”

Most birds can perceive ultraviolet light — invisible to human eyes — and see a greater range of colours than humans, and the Exeter scientists analysed how well pale and dark moths matched lichen-covered and plain tree bark, as seen by birds.

To do this, they used museum specimens including some from the collections of Bernard Kettlewell, who conducted famous research on the evolution of the species in the 1950s.

The researchers also created artificial moths, baited them with food and observed predation rates in UK woodland, mostly in Cornwall.

“Through a bird’s eyes, the pale peppered moths more closely match lichen-covered bark, whereas darker individuals more closely match plain bark”, said first author Olivia Walton, who conducted the research as part of her master’s degree at Exeter.

“Crucially, this translates into a strong survival advantage; the lighter moths are much less likely to be seen by wild birds when on lichen-covered backgrounds, in comparison to dark moths.”

In the experiment using artificial moths, lighter models had a 21% higher chance of “surviving” (not being eaten by birds).

“We provide strong direct evidence that the frequency of the peppered moth forms stems from differences in camouflage and avian predation, providing key support for this iconic example of natural selection,” Professor Stevens said.

The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

The paper, published in the journal Communications Biology, is entitled: “Avian vision models and field experiments determine the survival value of peppered moth camouflage.”

The birds that most commonly eat peppered moths include sparrows, great tits, blue tits, robins and blackbirds.

Prehistoric horses in North America


This 14 August 2018 video from the USA says about itself:

How Horses Took Over North America (Twice)

The ancestors of modern horses became so successful that they spread all over the world, to Europe, Asia, South America, and Africa. But in their native range of North America, they’ll vanish for 10,000 years. Until another strange mammal brings them back.

The illustration of Equus simplicidens–also known as the Hagerman Horse–is by Roger Hall. You can check out more of Roger’s work here.

Tyrannosaur family various species, video


This video says about itself:

Tyrannosaur family species comparison

13 August 2018

Welcome to the second round of the new dinosaur comparison videos. In this comparison video, we shall compare the different Tyrannosaurus family species or also known as Tyrannosaurids.

These dinosaurs have a strong jaw and are among the largest terrestrial predators to have existed in the world.

Tyrannosaurus rex, T-rex, is one of the largest land predators to have ever existed while Tarbosaurus is also on the top ten list along with others like Albertosaurus, Gorgosaurus, Daspletosaurus, Zhuchengtyrannus, Qianzhousaurus etc.

There are 11 tyrannosaurids that have been confirmed from fossils and these tyrannosaurus species differ in size and comparison so much that the smallest of them weighs less than one tonne and the largest weighs more than 10 tonnes.

The smallest tyrannosaurid measures only 5-6 meters in length while the largest measures more than 12-13 meters in length. These tyrannosaurus species all have one thing in common, the noticeable strong and rounded skull.

In this video of the Tyrannosaurus family species comparison, we shall take a more detailed look at the 11 tyrannosaurids, their size, where and when they existed.

So enjoy this video on Tyrannosaurus family species comparison.

Scarlet macaws, new research


This 2014 video says about itself:

Scarlet MacawsCosta Rica

Videos from Scarlet Macaw conservation projects in Costa Rica.

I saw scarlet macaws in Costa Rica.

From Penn State university in the USA:

Scarlet macaw DNA points to ancient breeding operation in Southwest

August 13, 2018

Somewhere in the American Southwest or northern Mexico, there are probably the ruins of a scarlet macaw breeding operation dating to between 900 and 1200 C.E., according to a team of archaeologists who sequenced the mitochondrial DNA of bird remains found in the Chaco Canyon and Mimbres areas of New Mexico.

Remains of a thriving prehistoric avian culture and breeding colony of scarlet macaws exist at the northern Mexican site of Paquimé, or Casas Grande. However, this community existed from 1250 to 1450, well after the abandonment of Chaco Canyon, and could not have supplied these birds to Southwest communities prior to the 13th century, said Richard George, graduate student in anthropology, Penn State.

Historically, scarlet macaws lived from South America to eastern coastal Mexico and Guatemala, thousands of miles from the American Southwest. Previously, researchers thought that ancestral Puebloan people might have traveled to these natural breeding areas and brought birds back, but the logistics of transporting adolescent birds are difficult. None of the sites where these early macaw remains were found contained evidence of breeding — eggshells, pens or perches.

“We were interested in the prehistoric scarlet macaw population history and the impacts of human direct management”, said George. “Especially any evidence for directed breeding or changes in the genetic diversity that could co-occur with different trade networks.”

The researchers sequenced the mitochondrial DNA of 20 scarlet macaw specimens, but were only able to obtain full sequences from 14. They then directly radiocarbon-dated all 14 birds with complete or near complete genomes and found they fell between 900 and 1200 CE.

“We looked at the full mitochondrial genome of over 16,000 base pairs to understand the maternal relationships represented in the Chaco Canyon and Mimbres regions,” said George.

Mitochondrial DNA exists separate from the cell nucleus and is inherited directly from the mother. While nuclear DNA combines the DNA inherited from both parents, mitochondrial DNA can show direct lineage because all siblings have the same mtDNA as their mother, and she has the same mtDNA as her own siblings and mother, all the way back through their ancestry.

Scarlet macaws in Mexico and Central America have five haplogroups — genetically similar, but not identical mitochondrial DNA lines — and each haplogroup has a number of haplotypes containing identical DNA lines. The researchers found that their scarlet macaws were all from haplogroup 6 and that 71 percent of the birds shared one of four unique haplotypes. They report the results of this analysis today (Aug 13) in the Proceedings of the National Academy of Sciences.

The researchers found that the probability of obtaining 14 birds from the wild and having them all come from the same haplogroup, one that is small and isolated, was extremely small. A better explanation, especially because these specimens ranged over a 300-year period, is that all the birds came from the same breeding population and that this population existed somewhere in the American Southwest or northern Mexico.

“These birds all likely came from the same source, but we don’t have any way to support that assumption without examining the full genome”, said George. “However, the genetic results likely indicate some type of narrow breeding from a small founder population with little or no introgression or resupply.”

However, no one has found macaw breeding evidence dating to the 900 to 1200 period in the American Southwest or northern Mexico.

“The next step will be to analyze macaws from other archaeological sites in Arizona and northern Mexico to narrow down the location of this early breeding colony,” said Douglas Kennett, professor and head of anthropology, Penn State, and co-director or the project.

Why young salmon leap


This 11 October 2012 video from North America says about itself:

Pacific Sockeye Salmon – Oncorhynchus nerka

Fall is the time of the Sockeye Salmon as they return to the same river beds they originated from to spawn and die, finishing their life cycle.

The sockeye eggs hatch in winter and the young salmon make their way down to the sea, sometimes hundreds of kilometers away. In the ocean they grow, if they can evade their predators which include everything from birds when they are smaller to whales, seals and fishermen as they grow into a prized commercial and sport game fish.

Then 4 years into their short life they return to the rivers, retracing their journey just 4 years earlier back to the same riverbed where they started life, spawning and dying afterwards, the cycle of the Pacific Sockeye Salmon continues.

From Simon Fraser University in Canada:

Young salmon may leap to ‘oust the louse’

August 13, 2018

A study by Simon Fraser University aquatic ecologists Emma Atkinson and John Reynolds reveals that young salmon may jump out of water to remove sea lice.

“Ideas about why fish leap include getting over obstacles during their upstream migration as adults, catching food and avoiding predators”, says Atkinson.

“However, these reasons may not apply to young salmon since their diet is composed almost exclusively of underwater zooplankton and their tendency is to scatter rather than leap when escaping from predators.”

Atkinson hypothesized that the leaping behaviour could be the fish’s way of removing parasitic sea lice, which is a common condition for wild and penned salmon off the B.C. [British Columbia] coast. Heavy sea-louse infestation is correlated with reduced growth, impaired swimming and competitive foraging ability for young salmon.

To test her hypothesis, Atkinson and her team caught wild juvenile sockeye salmon during their coastal migration away from the Fraser River. They held the fish in flow-through net-pen enclosures, half of which were covered with netting to prevent leaping and the other half were left uncovered to allow leaping. After three days, the team counted the lice on each fish.

The researchers found that, on average, the salmon that were allowed to leap in the uncovered pen had 22 per cent fewer sea lice compared to those that weren’t allowed to leap in the covered pen.

The researchers also found that it may take more than 50 leaps for a young salmon to dislodge a sea louse, which Atkinson acknowledges is a substantial amount of energy to expend. She says these costs may be offset by the benefits of successfully removing sea lice, but will have to be investigated in another study.