Archive for February, 2012
This is epic. I had little, well to be honest NO, idea has to how whales slept. I always assumed they were similar in physiological terms to dolphins, which I believe have half their brain (one hemisphere) sleep at a time whilst the other half is awake. However, this photo, and some articles and videos I just looked up, shows a pod of sperm whales in deep sleep whilst floating vertically just under the water surface.
It seems that scientists only first learned of this, and documented it, back in 2008 in the waters off of northern Chile.
For scientists have filmed whales drifting off to sleep for the first time.
A pod of six sperm whales was captured on film floating motionlessly and upright just below the surface of the sea off the coast of northern Chile.
The footage confirmed data evidence from 59 tagged sperm whales around the world that they snatch brief periods of sleep lasting about 12 minutes at a time during their ocean voyages.
Here is the footage the scientists captured.
“Many mammals show species-typical sleeping behaviour, such as dogs circling before lying down, lending support to the idea that sperm whales sleep during these drift dives.
“One exciting aspect of this finding is that it suggests that they actually might sleep in a fashion that we recognise as similar to sleep in terrestrial mammals. The sperm whale behaviour we describe seems to allow normal-looking quiescent sleep, possibly including REM sleep which has never been clearly observed in any cetacean. “
It also raises the possibility that the sperm whale – the largest toothed whale which can be 60-feet in length and which has the largest brain of all whales – may also be capable of dreaming.
Dr Patrick Miller of the University of St Andrew’s School of Biology’s Sea Mammal Research Unit
This research shows that sperm whales may completely ‘switch off’ for short lengths of time in the wild, effectively having ‘cat naps’ whilst they perform slow rhythmic dives. The research team think this study shows that sperm whales could require less sleep than other wild mammals.
So I posted a few days ago about leucism and albinism, both genetic disorders that lead to the pigmentation of animals not being expressed normally, so they appear completely or partially white. Anyway, reading up a bit more on things apparently there is also a genetic disorder that lands on the opposite end of the shade spectrum at black. It’s known as melanism.
Melanism is effectively the complete opposite of albinism. Both of these genetic disorders involve the regulation of the melanin pigment in an animals cells, whereas leucism affects all pigment types not just melanin.
Unlike albinism, melanism is the result of a dominant gene. So just carrying a single allele for this gene leads to the expression of melanism in one’s phenotype, (they appear darker). From an evolutionary point of view this adaptive trait becomes selected for when darker individuals have a higher fitness compared to lighter individuals and are better camouflaged to either elude predation or aid in the capture of prey.
1. The peppered moth. This species was predominantly white with black dots, giving it a peppered appearance, before the industrial revolution. After the industrial revolution began the pollution killed off the lichen on which the moths would sit on trees to camouflage themselves. The trees then became blackened by soot leaving the white peppered moths much more visible to predators. In a very short time this white morph disappeared and a black morph, that could much better camouflage on the trees, became dominant. So melanism in this example evolved to avoid detection by predators.
2. Black panthers. These are not a specific species of their own. As it happens they are in fact a black colour variant of a number of large cat species including, cougars, jaguars and leopards. Black variants in all of these species have been documented, but most ‘black panthers’ seen in captivity will be melanistic leopards (below left). Unlike peppered moths, these cat species have evolved black morphs to aid them in hunting at night, and avoid detection by their prey items. Leopards and jaguars, specifically, are known to inhabit dense jungles in the Americas, Asia and Africa, where a darker appearance would be a great deal more beneficial than for say a cheetah or lion living in open plain environments (they could be seen from miles away by prey).
As well as being found in many wild species such as squirrels, deer, bobcats, insects, seals and penguins to only name a few, melanism is often selected for by breeders in a large number of domestic animals, sheep, guinea pigs, cows, rabbits, cats and dogs. My folks have a black labrador and black tabby cat. You can still see her tabby lines in the right light as even though the hairs are all the same black colour, they have a different shine to them.
Furthermore, something awesome I read about was that wolves that are totally black, you know those freaky ones with the epic yellow eyes, actually received the melanism from the domestic dog. The mutation first arose in the domestic dog, and due to wolf-dog hybridisation wolves gained this trait.
Here are a few more images of melanistic animals found via a quick Google images search.
The image of a woman, yes Christians A WOMAN, was found in the crosscut of a branch by a man doing some pruning in his backyard recently. Although, I’m sure the religiously inclined will no doubt see whatever else they want in this crosscut as long as it confirms their faith and can be portrayed as evidence of the miraculous!
This is awesome page put up by BBC News! It gives you an idea of how deep animals can dive, w
Icy cold, pitch black and with crushing pressures – the deepest part of the ocean is one of the most hostile places on the planet. Only two explorers have made the epic journey there: 11km (seven miles) down to the bottom of the Pacific Ocean’s Mariana Trench. As a new wave of explorers is gearing up to repeat this remarkable dive, take a look at the mysterious world that they will be plunging into.
It’s a webpage that takes you on a journey from the surface of the ocean down to the very deepest depths, and gives you information about each zone. Suss it out!
This is a picture of the largest man in the world in 1903, Big Joe.
The largest man in the world about 100 years later is probably this guy, Manuel Uribe.
On a side note: were people always that graceful in the ‘olden days’, who puts their foot up to get a photo taken anymore? And that kind of action shot for the world’s largest man too in 1903?