evolution of life on earth

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The Silent Flying of an Owl. 

The video shows how effortlessly an owl fly’s compared to other bird species. 

A pigeon that has a relatively large body and small wings needs to flap furiously to produce enough lift. A falcon has large wings that move more aggressively so the bird can gain much faster speeds. 

Both birds create large turbulence in the air and noise as a result. Comparatively, the owl is the perfect night time hunter, silently flying through the sky.

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When Scientists Get Accidentally Artsy

A new exhibit at the Smithsonian’s National Museum of Natural History lies right at the intersection of art and science, showcasing the inherent beauty of skeletons — that is, fish skeletons.

ERAS OF THE EARTH

It wasn’t long ago that our Earth was thought to be only a few thousand years old and having been created in a matter of days. However during the scientific revolution that was taking place in the 18th and 19th centuries, minds like Darwin, Hutton and Lyell were challenging these age old theories. It was Charles Lyell that pioneered the theory that the forces of physics have remained the same throughout history, James Hutton also expressed that we can interpret the ancient past by studying modern day natural processes because the past and present are governed by the same laws. His findings reported that layers of sediment accumulated at around 2cm per year, he deduced that since mountains are sedimentary formations and thousands of metres high that the planet is more than a few thousand years old, but hundreds of millions. 

Our Earth is actually 4600 million years old, this staggeringly long time is almost impossible for the human mind to comprehend. As far as we know, life emerged as single celled organisms around 3800 million years ago, for the next 3 billion years it would remain as these minute unicellular organisms. This is the Precambrian, 4600 - 570 million years ago. 

To help us grasp the immense history of the Earth, a geological timescale was developed with each period marking a milestone in evolution and life.

CAMBRIAN 540 - 488 million years ago
Named after Cambria, an ancient name for Wales where rocks of this age are greatly exposed.
The Cambrian period sees explosive development of multicellular life with all the main modern phyla being established. Complex eyes and food chains evolve as well as active predation. Life is confined to the sea.

See Hallucigenia Opabinia Anomalocaris  

ORDOVICIAN 488 - 440 million years ago
Named for an ancient welsh tribe, the ordovices who lived in areas where rocks of this age are well exposed. Th oceans flourish with huge diversity of jawless fish, trilobites and gastropods and arthropods begin to dominate. The period ends with arthropods taking the first steps onto land. The end of the ordovician is marked by the first of the five major mass extinctions to hit the planet.

See Pterygotus Cameroceras 

SILURIAN 444 - 416 million years ago
Named for another welsh tribe, the silures, who inhabited areas where rocks of this age are abundant. Life in the oceans recovered from extinctions, magnificent coral reefs thrive in warm seas. Small plants begin to colonise the land and jawed fishes evolve.

DEVONIAN 416 - 359 million years ago
Named after the English county of Devon which is rich in Devonian age rocks and fossils. The Devonian period is also known as the age of the fishes. Jawed fish and placoderm fish rule the oceans, trilobites still thrive. Plants move from the coastal areas deep into land and the first forests spring up. Shark species increase in numbers and early forms of amphibian begin to spend more time on land.

See Dunkleosteus 

CARBONIFEROUS 359 - 299 million years ago
Known as the age of amphibians and named for the ancient coal deposits which were laid down during this time. The land is overrun with lush forests and swamps, The two main continents of the time, Eurasia and Gondwana are colliding to form the supercontinent Pangea. Winged insects take over the skies, oxygen content is much higher that today allowing insects to reach great sizes and the first true reptiles evolve, these are the first truly terrestrial vertebrates.

PERMIAN 299 - 251 million years ago
Named after Perm in Russia where rocks of the age are well exposed. Pangea is covered in harsh deserts, the number of species goes into decline, eventually 95% of them are wiped out in the worst mass extinction ever seen. Mammal like reptiles evolve. The first dinosaurs evolve towards the end of the Permian, they start as a few isolated groups and begin to increase rapidly in numbers.

See Scutosaurus Helicoprion Dimetrodon Gorgonops 

TRIASSIC 251 - 200 million years ago
Named after the word “Trias” referring to 3 rock divisions in Germany called bunter, muschelkalk and keuper. The climate of Pangea is warm and dry and dinosaurs have gradually assumed dominance in the land, skies and oceans. Mammals only exist as a few small species. Ichthyosaurs and plesiosaurs reign in the sea and reach phenomenal size.

See Proterosuchus Tanystropheus 

JURASSIC 200 - 146 million years ago
Named for the Jura mountains. Dinosaurs still dominate the land and the oceans flourish with marine reptiles and ammonites. The first bird start to appear towards the end of the Jurassic.

See Liopleurodon Megalosaurus 

CRETACEOUS 146 - 65 million years ago
Named for the latin “creta” meaning chalk which is laid down during this period and found widely now. Dinosaurs continue to dominate, the first flowering plants evolve. Sea levels are up to 300m higher than today in some areas, much of the land is covered in shallow seas. Carbon dioxide concentrations rise, slowly choking the atmosphere. The end of the cretaceous is marked by the extinction of the dinosaurs due to possible meteor impact.

See Archelon Deinosuchus Ankylosaurus 

PALEOGENE 65 - 23 million years ago
The world begins to recover, mammals and birds begin to flourish and exploit the vacant niches left behind by the dinosaurs, in doing so they grow to incredible sizes. The climate is gradually cooling and will continue to do so bringing the earth into an ice age. In these cooler conditions the first grasses evolve.

See Gastornis Paraceratherium Entelodon Andrewsarchus Ambulocetus

NEOGENE 23 - 2.5 million years ago
The climate is still cooling, ice sheets begin to spread down from the poles, as a result sea levels slowly drop. The size of forests reduce and grasslands take over resulting in vast open planes. Mammals dominate the earth due to their ability to adapt to changing environments and harsh conditions. Towards the end of the period early hominids begin to appear.

See amphicyon Glyptodonts Megalodon

QUATERNARY 2.5 million years ago to present
With an enduring ice age much of the mammalian megafauna have become extinct. Hominids have continued to evolve, only the homo sapiens survive as they are able to adapt.

See Megatherium 

Louis Agassiz - Earth’s Crust with the Evolutionary History of the Species, “Comparative Physiology”, 1851.

This diagrammatic history of life, proposed by Swiss-American naturalist Louis Agassiz, is very different from Darwin’s. Agassiz, an opponent of Darwin’s theory of evolution, shows the beginning of time as the center of a circle and the present day as the perimeter. According to a divine plan, different groups of animals appear in the various “spokes” of the wheel and then go extinct. Humans enter only in the outermost layer, and at the top, as the crowning achievement of all Creation.

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This is a “Penguin rover” used to study Emperor penguins in Antarctica.

It’s equipped with a spy cam to assist in studying these shy animals. Researchers found that approaching these emperor penguins normally would result in their heart rates rising, producing unreliable data.

This rover works very well, enough to even entice communication from the penguins. According to researchers the penguins were “very disappointed” when the rover didn’t respond, prompting the researchers to plan to have the rover playing penguin songs on it’s next trip.

(Via Cnet, Nature)

Think about shapeshifting, though.

Okay, because imagine somewhere along a planet’s evolutionary line, some or many species evolve shapeshifting abilities. Maybe slowly at first, but once those abilities really get going they evolutionary change isn’t slow, it’s fast. It looks like the bad science creationists always mistake for evolution, “If evolution is real, how come we never seen monkeys having human babies? How come I’ve never seen a crocodile turn into a bird?” Well maybe that’s never happened on earth, but shapeshifters are able to make selective breeding a sport and the best evolutionary advantage they have, making temporary form changes in themselves the default for their offspring. 

But, okay, imagine the development of a civilization of newly sentient intelligent shapeshifters. Imagine how you’d approach problem solving. 

Because the basic impetus of evolution, right, is that life changes to suit its habitat. But here on earth, life changes really slowly. So one of the most advantageous abilities earth life can have is the ability to change its habitat to suit it. Whether that’s building a beehive or inadvertently spreading good seeds around or hiding acorns or building giant industrial civilizations with paved roads and plentiful agriculture. 

Because that is honestly the fastest way to ensure you’ll be safe in your environment as a human (or not shapeshifting creature). Mess with the environment you’re in until it suits you (even if you wind up creating possibly catastrophic ecological disasters in the process, woops!)

But imagine how civilization would develop if it was always faster to change yourself to suit the environment instead. 

Like, we are only just discovering gene therapies, but I imagine in a shapeshifting society things like that would be discovered straight away. Aside form the fact that it’d probably be more easily accessed and developed because you’d naturally already have some capability for it without interference (’cause, you know, you have some level of shapeshifting), it’d also just likely be the way your society would have evolved to think about the problem. 

An early human sees something across a river that they can’t get to, they think “What can I build to get me across this river?” or “How can I divert or slow down this river so it is no longer in my way?” and they build a bridge or a dam or a boat. 

But an early alien see the river and thinks “How can I change myself so I can survive this river?”

Human thinks, “I wish I could travel farther faster” and domesticates horses and builds cars. Alien thinks the same thing and grows itself longer legs. 

So when humans approach the problems of space travel, FTL travel, wanting to see far away, wanting to see the very small, we build tools for ourselves: giant combustable cans that launch themselves into space, powerful telescopes, precise microscopes. 

The aliens address problems by developing medical technologies to change their internal makeup to push their forms further and further in their abilities to change to what’s needed. They’ve mastered gene therapy in a way we can’t begin to comprehend. 

They don’t build houses, they change to be comfortable wherever they want to be. They don’t build cars, they change to be faster. They don’t wear clothes, they just grow different skin. 

They travel through space on their own power, creating their own black holes and surviving them. 

It turns out this is what’s normal. Most planets with life eventually evolve some kind of advanced shapeshifting ability. It’s so clearly beneficial that, like sensitivity to light, if it can appear it always will and will always become better and more complex. 

Earth is weird

And the aliens don’t understand us at first. One time some of the healing microbes they all use get spread to a human, one of the first humans they’d ever seen up close, in her sleep. They didn’t mean to, having been watching this bizarre society from a distance for a while. The whole planet confused them, the choices this intelligent species would make. So they just wanted to get a closer look without interfering, but they messed up and got some regenerative microbes on this girl. They’re a little worried about the effects, but the microbes are smart (they were specially developed by the smartest bio-engineers in the universe, after all) and are able to figure out how a human is probably supposed to function and fix her up a bit without getting too wild or invasive. 

They hide when she wakes up. And when she wakes up she puts on her glasses. Then takes them off, confused. She holds the up to her face and then lowers them again. 

Nervous, she calls out “Mooom?”

Her mom opens the door, “What is it?”

“I can see.” 

The aliens watching don’t necessarily understand all the words, but the understand the body language well enough, and are confused. That can’t be right. But when they see the mother giving the girl and impromptu vision test, it seems like it is

The reasons these creatures wore things like that on their bodies, things like this girl wore on her face, lived in these strange boxes… the animals on this planet had reached an unprecedented intelligence level for animals who couldn’t shift. They weren’t just weird cultural choices. That girl had owned those inanimate things for a purpose

“Is it even possible?” their scientists wonder, “for that kind of intelligence to develop in a species that can’t change its own form?” 

We go down in all the records as an anomaly. Have you heard of Earth? That planet where intelligent life exists that can’t shift? They cannibalize their own planet to create environments suitable to them, to move through space, to fix their forms when they break. Instead of just adjusting their eyes to whatever space they are in, they have to build whole separate lenses to attach. They know things we don’t, about materials and “construction”. They are ancient. It took their species hundreds of millions of years to develop and they have existed for hundred of thousands of years. Any change their species’ form makes is slow over the course of thousands of generations. They are older than us all. Yet they do not even know what it is like to have wings. 

Science is Spiritual.

We can state, with high confidence, that even if there are other intelligent creatures in the universe, even humanoid ones, they won’t be like us. We are the only humans in the cosmos, the product of a very particular set of cosmic, geochemical and evolutionary circumstances.  To go from nonliving to living chemistry, and then from single-celled to multicellular organisms, such as sponges, many extremely complex steps had to be undertaken. To go from multicellular organisms to dinosaurs and then to mammals and eventually to primates took more complex steps, all resulting from random mutations and selective pressure, all unique and unreproducible.

Life should exist elsewhere but, if it does, the probability is that it will be simple, some kind of alien bacteria. Intelligent aliens may be out there in Earth-like planets, or in more exotic environments, but if they are, they are very far away. This is the striking revelation from modern science, one that should grab everyone’s attention:  We matter because we are rare, and our planet matters because it is unique. At the very least, it should inspire us to re-evaluate our relationship to one another and to the planet, beyond petty ideologies and short-sighted tribal disputes that fill so much of our time.

So the next time you hear a scientist saying something like “the more we know about the universe the less important we become,” beg to differ. The reality is precisely the opposite: The more we know about the universe, the more unique we become. What we do with this knowledge is, of course, a personal choice for each of us. To have this choice is the privilege of being human.

  ~   Marcelo Gleiser, theoretical physicist and cosmologist; professor of natural philosophy, physics and astronomy at Dartmouth College

World’s Oldest Fossils Found in Greenland

Geologists recently found evidence of ancient life in Greenland which they think dates to 3.7 billion years ago. If their findings are confirmed, that would make the fossils the oldest evidence of life yet known. The great age of the fossils makes reconstructing the evolution of life from the chemicals naturally present on the early Earth more difficult. You see, the fossils are too old. It leaves little time for evolution to have occurred, and puts the process of life emerging and evolving close to a time when Earth was being bombarded by destructive asteroids.

Most life on Earth depends on sunlight, but inside deep caves, darkness reigns. Despite being mostly cut off from the outside world, caves shelter an amazing array of organisms. Many of these animals have adaptations like long limbs and well-developed sensing organs that help them move and find food without light.

Waterfall climbing cave fish, found in just two caves in Thailand, lack eyes and skin pigment. But they have enlarged fins, which they use to hold onto or climb up rocks in fast moving streams.

Check out these models and other amazing cave-dwellers in the new exhibition, Life at the Limits: Stories of Amazing Species, now open!

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Charles Darwin [left] & Alfred Wallace [right]


Charles Darwin, a naturalist and geologist, would have celebrated his 208th birthday yesterday, Februrary 12th. He is well known for his contribution to the theory of evolution and our understanding of natural selection, explaining the diversity of life on Earth.

Alfred Russel Wallace, a naturalist, explorer, geographer, anthropologist, and biologist independently formulated the theory of evolution. He and Charles Darwin co-authored on several publications concerning evolution by natural selection. He is considered the “father of biogeography”.


On April 22nd, 2017, we will march for science, and we will march for these men, whose legacies have inspired generations of scientists driven towards understanding the complexity and enigma of life. 

It’s a family reunion 32 million years in the making! The fossilized shell (and partial skeleton) in my hand is the first genus of dry land tortoise ever discovered in the United States! They existed from the late Eocene to the early Oligocene, living in subtropical regions of Europe, Asia and North America. This ~32 million year old specimen was found in South Dakota. The living critter is an endangered Burmese Mountain Tortoise (Manouria emys), found in fragmented pockets from India to Indonesia. They grow to become the largest tortoise in mainland Asia and the fourth largest on Earth! Based on morphological and molecular studies they are the most primitive of all living tortoises and they are the only tortoise species to build an above ground nest, which is constructed out of leaf litter. The mother will actually protect her nest, doing her best to chase away predators! These are both specimens freely on display at the Prehistoria Natural History Centre and we have every intention of breeding our mountain tortoise to assist in the longterm survival of their species.