How did we Get Here? Mk.2 (Part 1)

After a stretched out and stressful exam period I'm finally back!! Hi again guys!

I realise I've kept you all waiting for far too long since the last post and so I've spent a few days reading up and researching to make this a good one, some of you may remember that a few months ago I released a post called "How did we get here" which told the story of how humans reached all the far corners of the Earth. Now this was back when I was revising for exams and I had no time so honestly, although the routes and general information is right, there's probably one or two mistakes, and I personally feel that it was a bit weak and lacked something.

But today I will correct that. Having spent days reading and watching various YouTube content, I'm fairly proud to present How did we Get Here Mk 2: Evolution.

To call the story of human evolution long is one hell of an understatement. Because technically our story starts as soon as the big bang happened. But let's fast forward a little to Africa in the Miocene era, a brief 13 million years ago, because this is where the story of the homo genus begins.

A lot of people say that we evolved from chimps, which is completely wrong. However, we did evolve from monkeys, somewhere between 13 million years ago (the Miocene era) and 4 million years ago (the Pliocene era), an ancient monkey species split into different species, the most notable of which are the homo (human) genus and the pan (chimpanzee) genus. So we didn't evolve from chimps, we merely evolved alongside them. It is thought to have been a long and difficult process but eventually resulted in the two species diverging largely by the time that the Pliocene era rolled around, but first, an important ancestor. Sahelanthropus.

Sahelanthropus is an important discovery because it is such an early point on our timeline. We have found extremely few parts of it, a partial skull (called Toumaï, "hope of life" in the dialect indigenous to the region of Chad where it was discovered), some jawbone and some teeth. While this isn't much to go on, we have managed to discover that it had a brain around 4 times smaller than our own and it has so many chimp - like characteristic that some experts argue that it should be classed as a member of the pan genus.
(see right - a cast of a Sahelanthropus skull)

At the moment Sahelanthropus' role remains a mystery mainly because we don't know when the human - chimp divergence occurred. Therefore, there is the possibility that it could be an early homo, an early pan or a common ancestor of both of them. As there is no general consensus yet, there's very little that I can say so let's fast forward to the late Miocene 6.1 million years ago to Orrorin, a controversial and disputed potential human.

Orrorin tugenensis (or just Orrorin) was postulated to be a species of homininae. Generally, the australopithecines are considered to be the human ancestors, but recently this has threatened their position by being a viable candidate for an even earlier ancestor of humans between the australopithecines and the human - chimp divergence. The fossils which we have discovered (pictured left) are currently being held in a secret bank vault in Nairobi, Kenya.

Now let’s get back to people, specifically, Australopithecus afarensis. This is one of the longest lived species of early human - like apes lasting from 3.85 to 2.95 million years ago. It is also extremely famous because of its discovery in 1974 where it was instantly assumed to be the missing link between the homo genus and the monkey like ancestors. The fossil discovered was nicknamed "Lucy" by Donald Johanson, after the Beatles song "Lucy in the Sky with Diamonds". This fossil turned out to be several hundred pieces of bone, making up 40 percent of the Australopithecus's skeleton and has been toured around the US although it now resides in the National Museum of Ethiopia.

This early hominin species lived primarily in Eastern Africa, and although it may have ventured a little according to fossil record, it didn't really seem to be in any hurry to colonise the world. This however changed with later species as Australopithecus Africanus (the first early apelike species to be classified as hominin) was discovered at 4 separate sites in southern Africa, the most famous of which being Taung in 1924 at which the "Taung Child" was discovered. A large variety of Australopithecus species eventually evolved and spread out around Africa where they continued to develop. However, it is important to note that these creatures were nothing like the humans we see today or even the cavemen that we picture, being our evolutionary predecessors, they were still much closer to apes than the homo genus.

So this seems to be where I'm going to leave off, to summarise, creatures like Sahelanthropus existed before the homo - pan divergence, although as we don't know exactly what species diverged or when it happened, we have trouble pinning down the exact time and saying what came when for this time period. Eventually, the species did in fact separate and evolved into animals such as Orrorin tugenensis which might have been a direct ancestor of humans and also the Australopithecus genus who we currently think were our direct predecessor. Eventually the Australopithecus genus spread out across large sections of Africa as the Pliocene era was coming to a close about 3 million years ago.

This post is getting fairly long and I still have about 2 or 3 million years of human evolution to cover so I'm going to leave this post here for now and hopefully release part 2 in the next day or two. I hope you guys enjoyed reading this, it feels pretty great to be back!

See you soon!

Daredevil

Superheroes are designed to be idols, I mean that's the whole idea right? They are characters able to do impossible things that exceed normal human ability and so we all think "Woah I'd love to be like that " and suddenly they become an aspiration, an idol.

And its pretty evident how trial and error has been used and new characters have been created to refine this process. I mean back at the dawn of comics you've got superman in 1938 - A man who is today criticised as overpowered simply because he can do everything, fly, shoot lasers, move fast, super strength; if you think of a power, odds are that he could manipulate his own extensive powers in one way or another to have that power. So there we have the prototype, appealing to a large audience.

Of course as time went on you get more and more superheroes made and each one is made to appeal to a particular audience so their morals, backstory, costume, weapons of choice and such are all moulded and designed to resonate with particular people. I mean you've got characters like the fantastic four for those who like science, more gothic characters like batman and punisher, and Deadpool to appeal to that little bit of crazy in all of us.

But one which I think is possibly my favourite character and origin story in the marvel or DC universes is Daredevil. I mean this is a superhero who is completely BLIND! Now that is an interesting choice.

Before I go any further with this I just want to make clear that yes this post is because I just finished watching daredevil season 2, no I am not just saying that he is awesome because I am currently obsessing over it and I am going to explain where necessary as if the reader has no knowledge of the subject so sorry to any seasoned marvel veterans reading!

So the premise of daredevil is that he loses his sight in a horrible accident when he pushes a man out of the way of an oncoming lorry. However due to radioactive exposure and the fact that he has gone blind, his other senses are heightened extraordinarily. 

Now this is all well and good but I want to ask just how realistic is this idea? You hear stories of people being able to hear better and use clicking like sonar to see after sight loss but how much science is there really behind these cases.

Lets get into it then.

So firstly this heightening of the senses is not fiction, it is 100% fact. In fact a paper published in the journal of neuroscience also provides an explanation.

It is shown that when a person goes blind, the part of the brain that would normally process visual data doesn't just go to waste, it is effectively rewired in order to process information from the other senses. So people without sight gain a greater capacity to use their other senses right off the bat thanks to this phenomena known as cross-modal neuroplasticity.

Then there's the fact that humans are nothing if not adaptable. Anyone can relate that after doing any one task for a time, they pick up small things about it and learn how to do that task better, improving at it as they practise. This is called learned behaviour and is how we learn how to do anything. It also means that even people blinded in later life will still learn to use their their other senses more acutely.




And this effect isn't even one way! People who go deaf experience a similar effect which makes them less susceptible to optical illusions and gives them better processing of visual information.

But what is the extent of these abilities? It is hard to say for certain because everybody is different and few large scale studies have been done to test this. There are however several spectacular cases in which people are actually able to navigate in a similar way to bats and dolphins by using clicking noises to create a sort of sonar, I'm including a video below of a man called Daniel Kish who has improved his ability enough to actually be able to ride a bike. 

So there you have it! That is why daredevil isn't as completely bizzare as it seems, even if it is a little exaggerated, it is based on hard science. Even if blind people can't her people's heartbeats or fight crime with their super senses, they are still able to train themselves even to the extent to being able to see with sound, which is a pretty incredible thing.

Once again thank you all for reading now if you'll excuse me Game of Thrones beckons....

How did we get here?

People are everywhere. Seriously we're like a bloody ants nest, every continent, every mountain, every habitable area. We're all over it. Even in place where humans really shouldn't be able to survive like the icy depths of Siberia or the scorching dunes of the Sahara, there's always a group of humans to be found just hanging in there at the limits of survival.

But how did we get here? It's an age old question that has perplexed even the greatest minds among us, with some looking to nature, some looking to religion and some even looking to the expanse of space above us! So today I'm going to talk about how humans spread all across the world from our humble beginnings in Africa! (You weren't expecting that were you?)

One thing that most people agree on in this area is that we came from Africa. Even among deeply religious people it is often accepted purely due to the extensive fossil evidence that shows our ancestors living there 2 million years ago. So humans popped up in Africa, and by humans I mean something like Australopithecus which wasn't really human but was nearly there.

Now as anyone who has been out in the wilderness or played a video game will know, humans have a tendency to explore. Whether its because they got hungry, curious or there just wasn't enough room, these early humans began to spread out and settle all over Africa. At the same time there were a lot of potential candidates for humanity existing at the same time, three of the largest being homo erectus, homo neanderthalensis and of course, homo sapien.

Homo erectus did quite well for itself, although it was really more of a stepping stone to more advanced species. Despite the fact that its brain wasn't enormous and it was only the first species to walk on two legs, it still managed to inhabit basically all of Africa and then eventually spread to what are now Saudi Arabia and Spain. From Saudi Arabia, they spread all throughout the middle East and Southern Asia, eventually even managing to get about halfway through Indonesia which is a pretty mazing achievement. This map shows their progress:


Next up is probably the most famous other human - the Neanderthal (homo neanderthalensis). These guys were much closer to modern humans in terms of evolution, in fact their DNA is less than 0.5% different to ours and there was a lot of cross breeding between the two species. In fact they are so close to our own species that they are often classified as a subspecies of homo sapiens. Ultimately, however, the dominant genome of homo sapiens caused the Neanderthals to die out either through absorption by interbreeding or maybe violent conflict. Either way they're not about any more and nobody is certain as to why.

But how far did Neanderthals get? They left Africa through Saudi Arabia much like homo erectus, but they took a completely different direction afterwards. Instead of sticking to warmer climates around the equator, they headed for what is now central Europe and north western Asia. However there is one catch that didn't really effect our upright amigos in the equatorial regions, the Earth was in the middle of a little cold period at that time. An ice age in fact.

This ice age limited the distance that the Neanderthals could go North as even areas further south than Russia could have been completely uninhabitable due to the cold. This pushed them further West towards the popular holiday destinations of Spain, France, Portugal and the like. They did this a long time before humans were even considering it and were habiting a big section of Eurasia  This is the sort of region they ended up in:

So homo erectus did surprisingly well for such an early species and Neanderthals probably could have done better if it wasn't for the pesky glaciers all over the place, but what about homo sapiens? How did we get here and there and everywhere?

We started off just like everyone else, in Africa. And in what was probably some sort of tradition at this point, we took the route out though the middle east and Spain. However instead of going anywhere really new, we just sort of hung around with our relatives in the areas already established as habitats, south Eurasia, Africa and the Philippines.

However shock and horror, about 60000 years ago there was another cold snap, but this one was pretty big and effected everything. It is thought that this cold snap reduced the population of humanity to under 10000, meaning we were hanging by a thread. However this ended and conditions eventually began to finally improve.

Branching out from the Philippines, humans made the next big leap in migration by managing to get to Australia and Indonesia, forming colonies about 50000 years ago.

When the ice age finally began to recede, a little after 50000 years ago, settlers finally began to poise themselves to explore and settle in the cold climates of northern Europe and Asia, A feat that was previously impossible due to climates that would freeze everyone really really fast.

However, a group of Asian homo sapiens then made the next great leap about 20000 years ago where they discovered an enormous ice bridge in north East Russia. In crossing it they became the first people on Earth to reach the Americas and colonies formed either side of the Rockies, eventually stretching down through Mexico to South America as well.

Of course there are places like Madagascar and New Zealand which we didn't colonise for a long time later until society had developed enough to invent boats, However from then on out, humans had colonies and civilisations on every continent except Antarctica. They which thrived and grew and squabbled and divided themselves with religion and politics and war and finally became this divided mess that we're living in today.

Humans used to be united, maybe not on an individual scale, but as a species, they would devote themselves to the cause of survival even managing to bounce back from being reduced to a few thousand in a cold, perilous world with nothing but their own brains to keep them alive. One day maybe we will put aside the borders and selfishness that divides out world currently and learn to live live this again but for the moment, lets just enjoy the good in this strange, broken world.

Thanks again for reading guys :) see you soon!

Why Gravitational Waves are Relativily Amazing!

Today I'm going to write about gravity. And not the ironically scientifically inaccurate film of 2013, but the enormous scientific breakthrough that was announced earlier today.

For those of you who haven't heard yet, it was announced earlier today that gravitational waves have been picked up by the LIGO detector in The United States. I was originally intending to do a post on either how we learn or why plants are green today but lets face it, I'm not just going to sit around and write about biology while my favourite science has made what is debatably the biggest discovery since the Higgs boson.

So I guess I should start by explaining what gravitational waves are and why they are so important? Okay. 100 years ago a pretty smart guy called Einstein realised why nobody could detect variations in the speed of light no matter how hard they tried, because it was a universal constant. And he postulated that that in order to keep it constant, even time and space would bend. And so, the theory of general relativity was born.

The theory that says that space and time are one thing called space-time, like the fabric of the universe and we're all like little bugs wandering around on our speck of dirt. However space-time isn't constant, as I said its like a big piece of fabric, and as a result, it is able to stretch, contract and twist. The thing that causes it to stretch and contract is mass. Yeah that's right, anything with mass, even you, warps the space around it. When it warps this space, things around it are drawn towards it and so it gives the illusion of gravity.

So what has this got to do with gravitational waves? Einstein predicted a lot of amazing things with his theory of relativity, gravitational lensing, Frame dragging, time dilation etc. And amazingly each one of these has been tested and proven experimentally one by one. Except for gravitational waves.

Gravitational waves are when an enormous amount of mass disturbs the fabric of space-time enough to cause what are effectively ripples of physical space. This can only happen however, if the object moves in an uneven way. A circular object spinning doesn't produce them, but a non uniform supernova explosion does. They are in the form of what are known as quadrupole waves, waves which oscillate in a similar way to a slinky, except its in three dimensions and instead of a string stretching, its space. So gravitational waves are like ripples in a pond, but in the universe itself.

So why can't we detect them? Even the biggest gravitational collisions caused by neutron stars merging, super massive black holes and even hypernova explosions, produce waves which only change the size of our space on Earth by a factor of 10^-21. And such extreme events are enormously rare across the universe! So in order to detect these, we need an extremely long piece of space to measure, and something to measure it against which is smaller than the fluctuation in space, as well as a really rare powerful event to happen a long time ago in a galaxy far far away (they travel at the speed of light but still might take millions of years to reach us).

How did we do it then? We're physicists so lasers are the obvious go-to answer. So physicists in America built the LIGO (Laser Interferometer Gravitational-Wave Observatory) with two detectors, one in Washington, and one in Louisiana. In each one, a singular laser beam is split into two and travel down two tunnels which are perpendicular to each other. At the end of the tunnel they are reflected off a mirror and come straight back. As the waves have travelled equal distances, they should come back together to make a wave which  exactly the same as the initial one, however if a gravitational wave passed through the system, it would mean that the space would contract in one direction more than the other and so the resulting beam would be different to the one that set off to begin with.

On September 14th 2015, a signal was measured which, looked promising, and various observatories were consulted to look for astronomical events which could have been the cause. This signal is now known to coincide with  the collision of 2 super-massive black hole which produced more than 500 times the energy of the starts in the visible universe. The statistical evidence also shows that the chance of it being a fluke are roughly 1 in 6 million. So in summary well done them!

This marks a new age for astronomy, now that we know that gravitational waves exist and can be detected, it could pave the way towards gravitational telescopes which would let us image our universe in entirely new ways! In fact the LISA project is currently looking at how to build  gravitational wave detector in space because, although the eventual goal for these devices is astronomy, they have  long way to go yet.

It is a true demonstration of human perseverance and intelligence that, 100 years after we predict something, we are still searching for it until we find it. Personally my favourite quote is by Isaac Newton - "If I have seen further, it is by standing on the shoulders of giants." and this has never been more evident than now. The work we do today was inspired by Albert Einstein, a Giant, like Newton and Pythagoras before him, and we can only hope that one day, maybe even we may be held in such regard.

Once again thank you all so much for reading and see you next time :)

Where are the Werewolves?

They prowl in the night and howl at the moon. They transform into the form of a bloodthirsty beast when the moonlight touches their skin. They tend to produce either completely fantastic or utterly awful TV and movies. That's right, today lets forget science for a bit and delve into the realm of monsters and magic with the topic of werewolves.

Ever since man has lived alongside wolves, there have been legends of a crossover between the two. Legends have sprung up all over the world from Norway to Mexico about men who turn into wolves, whether it's because of magic, a gift from the Gods or a disease, many different cultures around there world have their own version of this tale of human - canine combinations.

Firstly Norway - the Norse belief system was widespread across the northern regions due to the large amount of colonies in areas such as Iceland. As a result, places like Iceland and Norway both had the same legends about werewolves despite the 1500km gap between then. Northern Europe had a lot of wolves, like anywhere else, and as a result legends sprung up like wildfire. Norse mythology includes many wolf based creatures such as Fenrir, the monstrous wolf which was bound up to prevent it from becoming a threat. The respect for wolves is shown as Fenrir in fact bites off the hand of the god Týr in the process and it was said that he would kill Odin in the events of Ragnarök (the end of the world). However Norse werewolf tales stem from the tales of the Ulfhednar. In the same way that beserkers were considered to be warriors who became bears, the Ulfhednar were warriors who "became wolves". This is as close as the Norse got to werewolves - angry guys running around wearing wolf pelts, however some other culture took a more direct approach.

Native Americans (American Indians) have a hell of a lot of wolf legends because they weren't so much people - as they were a lot of smaller tribes with slightly varying belief systems and different legends in each tribe. Also there were wolves absolutely everywhere in North America. A lot of the legends involve the Gods granting humans gifts or curses brought upon people. However there is another legend which isn't specifically about wolves that has drastically contributed to the Hollywood image of werewolves. This is the legend of skin-walkers or the yee naaldlooshii. Seen as evil creatures, skin-walkers were said to be able to change into any animal that they wished at will. Sound familiar? This was generally associated with black magic and taboo, meaning that they were generally seen as evil and dark beings and were widely associated with death and fear. This legend probably arose from the culture being in constant close contact with the world of nature and the deep spiritual respect which they had for the Earth and animals around them.

Finally lets look at a completely different culture in a completely different area. Some of the oldest myths about werewolves aren't from the deep forests of native america, or the frosty north of Scandinavia, but instead from the picturesque Caribbean landscape of ancient Greece. Greek werewolf legends stem from the story of king Lycanon who, for reasons that scholars can't agree on, attempted to feed Zeus human meat, some say it was the meat of his son, some say that it was an attempt to kill Zeus. However what scholars do agree is that in the legend, Zeus discovered the attempt and turned king Lycanon and all of his offspring into wolves as punishment. The word Lycanthorpy (werewolfism) is actually thought to have come from this legend.

So there you have it, werewolf legends from across the globs. Inspired by the ferocity of nature and the begrudging respect that man had for the wolf. However some doctors have attempted to find medical explanations for possible cases of Lycanthorpy, refusing to accept that it is a figment of our imagination. 

One possible explanation, proposed by Dr Lee Illis is that historical werewolves were in fact sufferers of a type of disease known as Porphyria. Symptoms of this disease include reddish teeth, psychosis and photosensitivity which, to superstitious and religious people, could seem like and undeniable case of Lycanthorpy.

So ironically, looking to the past to find evidence, is more of a witch hunt. Originating separately in several cultures, and then twisted and romanticised by Hollywood, the story of the werewolf is one of sorcery and Gods. Nevertheless it may not exactly be science but it really is interesting.

Once again thanks so much for reading guys, see you all again soon! :)

How Big can Animals Get?

As humans, we're pretty small. Sure we're not like bacteria or insects, but in the animal kingdom, a lot of things are bigger than us. In today's animals, there's elephants, giraffes and rhinos, and as we go further back in time we see even more creatures that were enormous, giant sloth and beavers, and of course dinosaurs. So some animals are pretty big, but how big can an animal actually get?

To answer this, we need to consider what helps, and what limits, animals from growing. Obviously there's no one point after which and animal simply can't grow, but as animals get larger and larger, the problems become more and more evident. 


All animals need energy every day, we get it through food and drink where we eat stuff, then our body breaks it down and releases energy from it. However the bigger the animal, the more it needs. This trend was noticed by Dr Max Kleiber ho came up with this lovely graph that shows basal metabolic rate (the lowest amount of energy an organism uses) against body mass. Known as the mouse - elephant curve, it shows that an organisms basal metabolic rate is proportional to the mass to the power of 0.734. Basically the bigger something is, the more energy it needs.


So why is this such a problem? well we get our energy from our environment, from eating, drinking and in some cases sunbathing, but the more energy we need, the more we need to consume and so the more we have to eat and drink and eventually it would reach a point where groups of these animals would decimate any environment through trying to get enough food to survive.

Next up is movement. Its a little known fact that the more mass something has, the more it weighs! This shocking fact, dictates that the larger the mass of an object, the larger the force of gravity on the object. Why is this important? Because animals with legs spend the whole time that they're standing up fighting against this force. Sure animals like whales could get around it by not standing on land, however if they were in a non buoyant environment (AKA not the ocean), their organs would be crushed by the force of their blubber's weight.


There is a mathematical law called the square cube law, which says that as an object's size increases by a factor, the volume increases by the same factor cubed, so as animals get a bit bigger, their volume increases a lot more. This volume would also cause problems with heat transfer making it likely to be prone to overheating and therefore vulnerable to certain illnesses and potentially cause it to struggle with ordinary enzyme based functions.

So what other problems would an organism of that size face? Well it would need an immense amount of oxygen which would have to be circulated entirely around the body of the animal and so the blood pressure, amount of vessels and the speed at which it goes around the body would have to be enormous.

On top of this it would find it extremely difficult to find shelter from the elements or escape from any predators. 

So in summary, in the unlikely event that its skeleton could handle the immense weight of its own mass, it would be likely to be eaten by predators, starve, cook itself with its own body heat or simply stop working because homoeostasis would be impossible on a massive scale.

So that's it for now, I really enjoyed writing this, it feels like my first actual post in months. Thank you all so much for reading and see you soon :)

Deadpool!! :D

Wassup internet? I'm personally a geek, and being a geek, I love superheroes. That's right, everything from Batman to Spider-man, I am a very big fan of superheroes.

But for me one superhero (if he can be called that) stands out above all the others, and since he's getting so much publicity right now, I thought its a good time to do a post about him. Therefore without further ado, lets talk about Deadpool!

What you thought this was going to be a blog post about science? Well Surprise! This is a different kind of blog post.

In this I'm just going to talk about Deadpool, the character, the feasibility and hopefully make more bad jokes along the way. (Guys seriously if you haven't seen it watch the trailer first).

So who is he? Deadpool is awesome in its purest form. A by-product of the same government that created wolverine, Deadpool was formerly Wade Wilson, a cancer sufferer who was promised a cure. To be fair the government kept their promise, as a healing factor was implanted into him from a mutant, however he was later experimented on in an inhumane manner before being left for dead where his sheer anger kick-started his healing factor and so our hero was born.

Deadpool is scarred, both body and mind, as a result of the experiments performed on him, as a result this allows for an extremely interesting mindset for the writers to explore when writing his stories. However the most defining trait by far, is that he breaks the fourth wall!

Deadpool is in fact aware that he is a character in a comic book and often addresses his readers directly, allowing for even more interesting angles to take. Basically he is a character that you can do literally anything with, and a stroke of genius on the behalf of the creator.

Secondly, the feasibility. So what is it Deadpool can do? As previously mentioned, he has one hell of a healing factor, one of the most extensive ones in the marvel universe, to the level where he can survive stabbings, being blown up, being blown up by nukes, the vacuum of space and even the odd decapitation. Is this possible?



Nah.


It's highly likely that regeneration could be spiced into the human genome, especially as regenerative capabilities are demonstrated many people who have regrown small sections of fingers and toes and in each and every one of us in our livers and kidneys. But regrowing an arm? this would simply require an amount of energy and efficiency which our bodies can't achieve.

Deadpool also breaks the fourth wall, now for this to be possible, we would have to be living in an artificially created world and constantly observed by more intelligent beings for amusement. However this concept has reminded me of another interesting ideas.

Until recently it was accepted largely that it was possible that our entire universe could have been a hologram which we simply existed inside. However somehow they actually managed to test it recently and found no sign of us living in a hologram. Which is good I guess because that way nobody can accidentally turn off the universe.

http://www.iflscience.com/universe-probably-not-hologram

Also I should probably mention that Deadpool isn't actually intentionally breaking the fourth wall. He is insane and thinks that he is in a comic book, but as luck would have it he is actually right.

Anyway guys that's Deadpool, an inappropriate, crazy, violent merc with a mouth.

Sorry about the lack of posts but I'm swamped at the moment, see you all soon! :)