We’re slower than Cheetahs, less agile than a gazelle, lack the point teeth of a lion and can’t climb half as well as a chimp. Surely technology is our saving grace, the only thing we really have going for us?

Surprisingly, no. Contrary to the classic conceptualisation of people as totally reliant upon technology, we do have some surprising physical adaptations to Savannah life. In particular, we sweat.

As disgusting as this is, leopards look on with envy.

Sweating allows us to engage in endurance running. Now, again, running might not seem to be something people are particularly good at – there are a whole host of other animals that can easily outpace us – but they can’t out sweat us.

Combine running with sweat and you have a bipedal ape with the ability to run long distances in the blistering heat, which is something most animals can’t do. Steadily a running man would tire out his prey as he chased it across the Savannah until it collapsed of hyperthermia and he was able to claim his prize.

Endurance running is the ace up our sweaty sleeve and allowed us to become one of the dominant predators on the Savannah in a war of attrition. Which of course begs the question, when and how did this ability evolve?

Which of course calls for some SCIENCE!

The ability of our ancestors to manage heat (or thermoregulate, if you want to sound sophisticated)  has long been an avenue of research in EvoAnth since it ties into that other interesting question – when did we loose our fur? Unfortunately, that means that running and thermoregulation has been an area that was somewhat neglected since people care more about where all our fur went.

This means that all the mathematical models used to calculate the heat management abilities of hominins are based around someone who is standing still which isn’t particularly pertinent to those studying running. So some researchers decided to sort out this oversight and adapted an existing model to be applicable to a running man.

The result is pages and pages of rather complicated maths which I in no meaningful way understand. However, I do know that when they inputed the data for modern Homo sapiens the predictions the model made were accurate when compared to actual, non-imaginary Homo sapiens. So it is seems to be the mathematics is fairly sound, even if I am in no way qualified to comment on it.

I'm not technically qualified to comment on EvoAnth either, but I think I hide that fact quite well

Satisfied the model works, they then ran the calculations for to work out the thermoregulatory abilities of other species of hominin in an effort to see when endurance running became physically possible. Unfortunately, they didn’t have all the data needed to make the model as accurate as possible.

Assumptions had to be made regarding the sweating ability of the past species, as well as how much fur they had and how efficiently they could run. If they used the data from modern humans to fill in these blanks then surprisingly, they found that pretty much every species of hominin could endurance run.

However, for some species these assumptions are particularly weak. Australopithecines weren’t as good at bipedal locomotion as later species, suggesting they couldn’t run as efficiently as modern humans meaning this figure isn’t accurate for them and they would likely be unable to engage in long distance running.

Then there’s the evolution of the human louse, which indicates that hair loss only got to human or near human levels during the time of Homo erectus, eliminating Homo habilisand other earlier members of our genus from those capable of long distance running.

So what about sweating? Was Homo erectus a good enough sweater? Well the maths reveals that provided they could sweat at >80% of the efficiency as modern humans then they could engage in endurance running. Since they had a body that is physically rather similar to modern people this does not seem like much of a stretch.

The predictions for Homo erectus, with the horizontal lines reflecting their ability to loose heat and the curved lines being how much heat is generated by their running.

So, it would seem that Homo erectus was the first hominin that could’ve engaged in long distance running – except for during midday – although that doesn’t mean they actually did. Which leads to the follow-up question of how did they evolve this ability?

Well, given that endurance running requires that they can simply run, sweat and not have much fur (all of which could develop for other reasons) then it might well be that long-distance running is simply a side-effect of other selection pressures.Our ancestors got good at running to sprint and escape from predators/chase prey/whatever and were able to sweat well because the climate was so hot and bingo, they’d accidentally developed the ability to run for long periods of time.

Of course, there might have been other factors involved and I await any further research that tries to shed light on exactly why endurance running emerged. Also, as the field of recreating the bipedal abilities of past hominins expands, the data regarding the running efficiency of these species will improve and so more accurate results can be obtained.

However, given how Homo erectus is already known to be rather human in terms of physiology, I doubt more accurate results will drastically alter the findings of this paper.

For example, say you lived your whole life in a town where every fast food restaurant sold 1 burger in each meal.  Then, you moved to a new town with two fast food restaurants. One advertises it sells 2 burgers in each meal, for the same price as another outlet which does not say how many burgers are in its meals.

Now, having just moved in all your cooking stuff is still in boxes so you decide to go to one of these fast food places. Which one? Likely you’d go for the one which gives you 2 burgers in each meal since it’s better than the average meaning it’s a good deal and, on top of that, the other place will probably only give you 1 burger.

There is the chance it does 3 burgers, but given all your past experience this is unlikely so are rather adamant about visiting the one which you know for sure gives you extra burgers. “A bird in the hand is worth 2 in the bush” and all that.

Birds...burgers...this metaphor is rapidly spiralling out of control

However, there are some situations in which using this method isn’t the best way to maximise ones return. However, short of being able to see into the future and identify which option gives the best reward, it is the most efficient using what we know.

So it’s quite easy to see how it would be beneficial in a survival context. If our ancestors stumbled across a particularly rich fruit tree, it would be unwise of them going off and trying to find an even better one. Given the average rate of return, it is unlikely they would.

Even though there might be an even better fruit tree just round the corner, overall basing our decisions on the average rate of return is the best. Always looking for better fruit isn’t the best method.

Especially in Vegas

Now, if one were to design an experiment around this principle how would one do it? The simplest way would likely to be to repeatedly present a test subject with 2 boxes of rewards but only show what is inside one of them.

If they were using the average rate of return to make their decision, one would expect that they choose the known amount when it is an above average reward (based on the boxes they had been made to choose from so far) and the unknown amount when the known reward is below average. If the amount is the average reward then the test subject shouldn’t really care which box they choose, unless they’re a fan of the gamblers fallacy.

Now, what if the test subjects are capuchin monkeys (the coolest kind of monkey)? Would we expect them to perform in a similar manner? Well, you can stop hypothesising because some researchers actually ran this experiment and found that they calculated risk in a very similar manner to humans, picking unknown v known based upon the average rate of return.

In other words, monkeys use the same method for dealing with uncertainty as people do. Or perhaps that should be we use the same method for dealing with uncertainty monkeys do. Humans, after all, could deal with eating a little bit of humble pie.

Make that a lot of humble pie

Ordinarily I would place this within an evolutionary context, perhaps making some final conclusion based around evolutionary pychology. With this study however, I will not.

It isn’t that the study is flawed – it controls for a larger variety of variables some of which even me, as awesome as I am, didn’t think of. It’s just that using this technique doesn’t seem to be a product of our monkey heritage.

Using the average rate of return seems to be the method, and the people and monkeys involved in the test got pretty close to getting a perfect score. How then do we know that it is not convergent evolution, rather than a product of our ancestry? Given it seems to be the ideal state, most species would surely drive towards it regardless of their heritage.

Further, it seems to have a fairly major basis in learning. Whilst the biology behind learning might be evolved, ultimately the  specific techniques such as this one need not be, Pavlovian conditioning – or any of a whole host of other possible explanations – could do the rest. All that is required is that an animal can identify the best strategy, not evolve it.

Which is something the researchers seem to agree on, avoiding mentioning evolutionary psychology through the length of the paper.

So the big conclusion of this paper is to further help us understand how animals think, not evolution. Which is pretty cool in of itself, I think.

Given all of this, it’s easy to forget that the environment has been constantly changing since our planet first formed. It isn’t just a current issue, everything you see and hear has been shaped by aeons of climate variability.

When I say aeons, I mean aeons: humanity has only existed since around the "r" in "warmer"

Including us, Homo sapiens. We are the children of climate change. And not just in the sense that it was one of the many factors that influenced our evolution. No, a paper published last summer purports that climactic variability was one of the primary driving forces behind the emergence of the lineage which gave rise to you and I.

And not just us either. Back before everyone’s favourite closest relative, Homo neanderthalensis, we lived alongside dozens of related species. Several variates of Australopithecines, Paranthropines and Homo(ines?) lived side by side in ancient Africa. Most of them eventually went extinct, but our ancestors continued on to become the success story. Why? Once again, the answer seems to be climate change.

But let’s not get ahead of ourselves. Before understanding how the climate picked us over our cousins, lets look at how this much maligned process did something creative and prompted the development of many new species.

Yes that's a silly question, but then people also ask how explosions create order. The world is full of silly questions.

Evolution, ya’see, does this thing called “adaptive radiation” in which, upon entering  a new environment, an organism will diversify into a variety of forms. It does this because this new environment will be full of new niches a range of organisms can exploit. Thus, instead of having just one organism trying to be the best at one thing, there is room for many organisms doing many things.

“But,” I hear you say, “look at the graph you just posted. There isn’t any new environments appearing, it’s just constant variation.” Ah, but climate variation can have a similar effect as the creation of a new environment.

If there’s just a warm environment, only warm adapted organisms will flourish. If it’s an environment that fluctuates between hot and cold, suddenly there’s space for cold adapted creatures to start developing. New niches are created by new variability, even if the absolute environment remains pretty much the same.

And if you look at when the climate was the most variable in the past few million years, sure enough you see it’s ~2.5-1.5 mya, when the hominin lineage starts to diversify into a myriad of forms.

The grey bit is when the climate is extra variable

Amongst the variety of new possible specialisations a variable climate creates, it also creates the opportunity to not specialise. If an environment is fluctuating between hot and cold, both cold and hot adapted animals will be favoured. But if an animal is well suited to both the hot and the cold? It’ll kick evolutionary ass!

And – as you should already know – that’s what we (or, more accurately,Homo erectus) did. We decided “jack of all trades, master of none” was actually a fairly good motto and became specialised at being generalists.

But is not the “master of none” part a concern? Although we might have been well suited to a variety of environments in each of those we would be second place to someone who was well adapted. However, in a fluctuating environment even being second best can win you cold.

For example, if you have a generalist and a warm specialist in an environment that fluctuates warm/cold the following would happen. First year is warm, you (the generalist, remember?) have 2 babies, the specialist has 3. The next year is cold so you have another 2, the specialist has none. Third year is warm again, so he has another 3 and you have 2 bringing the total to…6 each?

Not quite. See, your babies also had babies and have been geometrically increasing. He has 3, you have 2. Then you have 2, your babies each have 2 (they’re fast growers) and you have 6 total members of your species. Then the specialist has another 3, making them 6 total whilst your 6 individuals double again to become 12.

Still with me?

So, climate variability made room for new species and allowed us to diversify. One of these organisms was a generalist and so coped well with increasing variability and eventually out-competed all these variants. This species gave rise to Homo sapiens.

Well….

This study isn’t perfect. For starters, it merely identifies a correlation between when diversification/generalisation occurred and when the climate is variable. And, as you all should know, correlation does not mean causation.

The second flaw was pointed out when this work was presented at HOBET: the climate data used covers a wider area than Africa where we evolved. Thus, the specifics of the climate our ancestors lived in might be different which would alter the results somewhat.

However, all the modelling is set up. All the researcher needs to do is input some African data and see if his conclusions still hold true.

I look forward to that.

The reason this pattern has appeared across most of my posts is because it’s a pattern that appears across most of evolutionary anthropology. That’s because bones, whilst providing a lot of information on the past, do not answer every question we ask. Humanity’s ability for curiosity has always outpaced its ability to actually answer those questions.

But not its ability to invent answers

Nowhere is this more apparent than when studying the evolution of speech. Being one of the cornerstones of our success, it’s a deeply interesting issue. With speech we can communicate complex ideas, allowing increasingly impressive feats of co-operation eventually culminating in the technology and civilisation that has enabled us to spread all over the planet.

At the same time it leaves behind very limited traces in the fossil record. The vocal tract, being fleshy, decays along with most of the other apparatus involved in talking. And lets not forget that speech itself doesn’t fossilise. Prior to the invention of writing, we have no clue what was said by anyone which makes tracking its evolution somewhat…problematic.

Prehistoric fools, record your words not your hands!

As such, most attempts to unlock the mysterious story of speech have to focus on the other fingerprints speech leaves behind, or even abandon looking at fossil evidence entirely.

For example, the Homo erectus vertebrae from Dmanisi seem to be identical to modern Homo sapiens and so it is argued they could’ve supported the repository muscles needed for speech which attach there. A Homo heidelbergensis/neanderthalensis cranium from Atapuerca has an ear canal adapted to hearing the frequency humans speak at, unlike chimps.

There’s also Robin Dunbar, of social brain hypothesis fame, who has used calculations of group size to try and work out when speech became a necesity to maintain group cohesion. It’s all frightfully ingenious stuff that allows us to get a clearer picture of the development of speech than we would have had if people had simply given up when direct evidence disappeared.

Written by QUITTERS

And now new research has come out to join this rag-tag bunch of heroic papers, chipping away at the past despite having all the odds stacked against them.

This work is based around the fact humans don’t have air sacs in their vocal tract, whilst every other ape species does. Parsimony would thus suggest that lacking airsacks is an evolved feature in humans, rather than every other ape happening to develop them after they had split off the lineage that led to humans.

The exact function of these air sacs is unknown, but the scientists in this study don’t really care about what they do. It’s what happens when they disappear that they’re interested in.

Useful for something. Probably.

Now, here we run into the classic EvoAnth problem: how to study this? Individuals from the past have lost their air sacs, even if they had them to begin with, which makes understanding how this changes speech ability quite difficult.

And one can’t simply compare the speech abilities of modern humans and chimps since there are a lot of other differences between them, how do we know which are the product of air sac absence? What they needed was something where everything was the same, they could just attach or remove air sacs to see what happens; something they could control the variables for….

What they needed was a model.

Not that kind!

They then blew a bunch of air through all these models to see what would happen. The results? Removing air sacs lowered the frequency at which loudest sounds were made, increased the power of those sounds and moved them apart on the frequency spectrum so each sounded more distinct.

They then hypothesised that this might have a benefit to speech by allowing the wide range of sounds needed to be articulated more clearly by making them sound more different. It would be difficult to hold a complex conversation in a language where everything sounded the same, after all.

So they made their models make the vowel noises and then got people to try and identify which vowels were being said, the idea being that if air sacs make things less clear then people would misidentify the vowels made by those models more often.

And low and behold, they did.

More bland looking graphs for your amusement!

Now there are some problems with this part of the study, such as small sample size, the most eyebrow raising being that we’re asking people. People who’ve spent their whole life attempting to identify these sounds and so are exceptionally good at it, which might amplify an otherwise small effect size.

But they do concede these problems and admit this is merely a preliminary study and they hope to solve this issues in the future. I look forward to when they do, but in the mean time the more solid data regarding absolute frequencies is robust enough to suggest the loss of air sacs is rather importance in the evolution of speech.

Or since we’re talking about the loss of something, perhaps the operative term should be devolution?

Oh, and the most exciting thing about this work? Whether an organism had air sacs or not is detectable in the fossil record. That’s right, we can go start studying the evolution of language in the long dead.

EvoAnth: 1, decomposition: 0

Hopefully that will make finding older posts easier whilst allowing new comers to see if there’s anything I’ve written in the past that piques their interest, without having to trawl through archived pages.

As always, the feedback button is there if you have any suggestions to improve that page, or just improve this blog in general.

But being tiny is only scratching the surface of the bizarreness of H. floresiensis. The hobbit made tools on par with the humans of the time, despite having a brain 1/3 their size and lived during a time when all other hominins had died out (except H. sapiens).

Understanding the hobbit would revolutionise how we view human evolution, yet coming to terms with our miniature cousin is something we’ve yet to do. Why is it tiny? How could it make such complex tools? What species did it evolve from?

Did it have furry feet?

One persistent answer to the mystery surrounding the hobbit has been that it isn’t especially mysterious.  Almost as soon as it was categorised as a new species people were arguing that it wasn’t, that it’s actually just a Homo sapiens with some kind of condition.

Microcephaly – a condition in which a person’s head is signficantly smaller than average – was one of the first conditions proposed to explain H. floresiensis since it can produce individuals with a brain size on par with the hobbit. Although this typically greatly impairs intelligence, it would mean that there was a population of modern humans present who could produce the complex tools discovered.

Yet shortly after microcephaly was suggested it was refuted. Cranial scans of sufferers revealed that they had a significantly different brain shape than the hobbit did. Further, although victims of the condition have been known to be short, none have a skeleton similar to those found on Flores.

"For doubting my taxonomy you recieve DEATH GLARE!"

But that was not the end for those who dispute assigning the specimens from Flores to a unique species and in the intervening years they have suggested many other conditions which could explain the existence of the hobbit without drastically altering our understanding of human evolution.

The most recent pathological explanation for H. floresiensis is that they are “myxoedematous endemic cretins.” Now, I must confess that before I started researching this topic I only knew what 1/3 of those words meant: endemic (or “unique” to you lesser, non-sciency mortals).

Drat.

On top of that, even “endemic” has a different definition in the world of pathology.

Double drat.

So I guess it’s time to twirl my moustache and play “catch the definition.”

The operative part of that sentence was "twirl my moustache".

Which was surprisingly easy.

Clinically…[myxoedematous] cretins are usually distinguished by…extreme growth retardation, facial dysmorphism [differences], myxedema [insufficient amounts of thyroid] and less severe mental retardation

Further, clinical definitions typically come with a precise suite of features used to define the condition, allowing us to diagnose the specimens from Flores! Which is exactly what recent research has done, taking the extensive list of features used in the diagnosis of “cretinism” (I’m still not sure if I’m comfortable using that word) and applied them to the hobbits.

The comparison table is very long and the end result of this in-depth comparison? They aren’t alike at all. Other than the short stature, the only skeletal feature Homo floresiensis has with cretins is their humerus is twisted in a similar manner. Pretty much every other feature used to diagnose myxoedematous endemic cretinism is absent.

Rather hilariously, this includes having a normal sized brain! That’s right, the disease being used to explain why there were small-brained, small-bodied hominins on Flores does not result in small brains. Cretinism also results in differently shaped feet and hands, which the hobbit doesn’t have; it also means people keep their milk teeth, which the hobbit didn’t…

And this is just a fragment of a very long table

However, the hobbit skeleton doesn’t look as it would have when it was inside a person, having been altered and damaged by spending thousands of years in the dirt and during excavation. This introduces a potential source of error, since these specimens might only be different because they have been changed by such taphanomic (“after death”) processes.

Claiming that this is the case is one of the arguments put forwards by those suggesting the hobbit is just a cretin, suggesting that the skull size has been reduced hence the discord between the small-brained hobbits and the large-brained human cretins.

For example, they suggest that the skull used to be larger as there was cartilage between the bones, but this decayed and the bones came closer together, eventually fusing into a smaller sized skull.

Such alterations leave behind fingerprints on the bone, so to speak, which can allow this claim to be tested. As one might have guessed by now, it turns out those suggesting the hobbit is a cretin are wrong.

The areas which have undergone deformation don’t seem to align with where bones would merge if cartilage disappeared. On top of that, there are sections of the skull which aren’t deformed but should be if what the pro-cretin crowd say happened happened.

(B) is the hobbit, with areas of deformation highlight in green. The numbers on (C) mark where deformation should be.

So, it would seem the hobbit is still the member of a unique species: Homo floresiensis. Which means the mystery is a mystery again.

For scientists, who love to investigate, this is good news. For those who just want easy answers well…

Triple drat.

Via smbc-comics.com

Of course, as with just about anything else in EvoAnth, this is easier said than done for pretty much the same reasons everything else is difficult – we don’t have early societies on hand to study. Archaeology isn’t especially helpful here either, since we’re talking about behaviour and that doesn’t preserve well.

Instead we must look for modern analogies, which is where anthropology steps into the limelight. By looking at modern hunter-gatherers and why they share food, anthropologists have developed models that attempt to explain how that behaviour arose in the first place.

Luckily this picture already has a witty caption.

One of the more persistent explanations is that they do so out of a sense of egalitarianism – all are equal so all get a share. Such a hypothesis has fuelled the romanticised view of hunter-gatherers as leading a “better” life, living in balance with nature and sharing food so nobody has to worry about anything.

And it’s easy to see why this explanation worked its way into both scientific and general culture since it seems to fit with the evidence (no known hunter-gatherer group denies any member of the tribe access to a kill) and our own perception of food sharing (when we give a friend food we rarely do so with concious ulterior motives).

But on the other hand there are a few flaws with this explanation; namely that there is little direct evidence for it. Although it fits in with what is known there are many other factors at play which could also be explanations. Many tribes, for example, view a carcass as communal property so the hunter is not allowed to hoard it.

Directly proving that hunter-gatherers are egalitarian instead of bending to social convention would require a novel experiment.

Because anthropology is famous for its experiments.

Which is exactly what they did do. To remove all the confounding variables of society and stuff, they invented a game to play with hunter-gatherers based around arbitrary things they had no experience of.  If they were egalitarian at heart, surely they would still play fairly.

Two games were played, the ultimatum game and dictator game. In the first one player divided a stake with another, offering them a share. The receiver could either accept the share or decline it in which case neither would get anything. The dictator game was almost the same except the receiver had no choice – the proposer could divide as they wanted.

In the ultimatum game the average share offered was 30% of the stake (which was rejected 24% of the time) whilst it was only 20% in the dictator game. This is considerably lower than the results when one plays the game with people from “complex” societies such as the West.

The results from the dictator game

But, like the egalitarian explanation that came before it, there are some flaws with this research. Importantly, people tend to be rather different. One of the biggest drawbacks to making general inferences from anthropology is that different groups vary quite a bit, so whilst this shows one tribe isn’t inherently egalitarian doesn’t mean another is.

Further, they were playing with seemingly arbitrary stakes and so the desire to share them may have been neutered somewhat. If I cannot see why you need a share I might not be inclined to give it to you, even if I am a good person at heart.

However, that is besides point since what these results mean is there is still no evidence for egalitarianism. It’s all well and good pointing out how it’s still possible but there’s nothing here to indicate it is actually the case.

So based on the current evidence it would seem hunter-gatherers are secretly selfish.

I’ve nominated you for the Versatile Blogger Award. I like your blog and thought based on its content you deserved this award.

I don’t really know quite what this award means; after all, is a blog confined to posting on a singular (albeit broad) field of science truly “versatile”? Is there any merit to a chain letter award? Are all these questions pointless navel gazing?

Probably, so with good graces I accept this VBA and thank mpbulletin for vindicating the existence of this blog (and hosting the VBA image I’ve sneakily taken and put at the top of this post). It was started to spread information on an interesting field that unfortunatley has information rarely spread about it and this award shows that at least some people are listening.

Also, thank you for feeding my ravenous ego. I haven’t had a subscriber in 5 days and it was getting hungry. And since I am a kind soul, I shall feed the egos of 15 bloggers as the award mandates.

1. Science defined; an introduction to science. Simple, yet fun
2. Brian Glenney, of Simian rivalry; a kind-hearted soul whose posts have a unique wide-eyed fascination with the world.
3. Acollectionofatoms; anthropology and economy. He posts about the economy in a way one expects to turn into a political rant, yet it never does. A refreshing change.
4. Carrie Glenney, of Simian rivalry (no, I’m not cheating by doing the same blog twice; seems to be always thinking, and those thoughts always seem to be interesting.
5. EyeonICR; a blog providing critical reviews of Institute for Creation Research articles. A noble endeavour.
6. Quasar; creating an evolution game. ‘Nuff said

Oh dear, I seem to have run out of bloggers. Please don’t hurt me, I tried my hardest.

Anyhoo, 7 random facts

1. Capuchin monkeys are my favourite monkeys.
2. I think it should be Homo sapiens neanderthalensis (or some variant of that)
3. I’m trying to grow a bonsai tree
4. There was a bomb scare during my last archaeological dig.
5. I’m partial to Star Trek
6. I eat my cereals without milk.
7. I named my archaeology trowel “Bob”

http://sciencedefined.wordpress.com/

Evolution;
Evolution;
Make and fix and mend;
But now it’s at an end;
Evolution!

I’ll give the Americans reading a minute to pick their jaws off the floor and get over the fact a school play is opening with an evolution-based musical number. It shouldn’t be surprise, here in Britain the acceptance of evolution is exceedingly common place.

Another common view – both here and around the world – is the sentiment conveyed in this song. That evolution no longer affects us. No doubt you’ve read something talking about how humanity has removed itself from the natural world to such an extent that we are no longer evolving.

Such statements are typically incorporated into some kind of rant about the evils of humans. About how we’ve divorced ourselves from what is good and natural so much that not even evolution can touch us now.

I find their lack of faith disturbing

On the surface this idea seems to make sense: over the past few thousand years we’ve been effortlessly working to not die malnourished on some ratty bit of grassland. A noble goal, in my opinion.

This has turned humans into experts at niche construction (the sciency word for organisms which create their own environment) and if we’re building our own niches then why do we have to adapt? We can just keep things ticking comfortably along the way we like them.

And this does seem to be the case. A disease tries to kill us, we set doctors on it. We feel peckish, we head down to the local supermarket. A lion runs at us, we shoot it. We get cold, we were an undershirt…the list goes on. Every time evolution tries to point out we have no right having 7 billion members of our species sprawled across the globe, we punch it in the metaphorical face.

We work to maintain a stasis whereby we remain alive and happy, regardless of the environment.

Our ancestors smell, we build an extra rung on the tree of life

However, whilst ostensibly valid this logic runs into a pretty critical flaw: we don’t keep things the same. Humans now occupy more extreme territories than they have at any point in the past, from the Antarctic to Space, in larger groups than at any point in the past, with a different diet to at any point in the past.

This is the premise of inceptive niche construction and is an aspect of our technological advancement that is frequently overlooked. Basically, it is pointing out that changing our habitat can create new environments or allow us to inhabit previously unaccessible ones.

Before we developed sufficiently advanced technology we would’ve been inhabiting a rather different environment than we do today. Even after removing various selection pressures – suh as diseases and lions, as previously mentioned – we’re still living in a drastically different environment to the one we would typically be in.

But of course we are also generalists, able to survive quite well in a large variety of environments. Perhaps our new environment, despite being different to the African Savannah our species grew up in, is still within our tolerance and we do not have to evolve after all.

Thus the question becomes whether the selection pressure we create by using out technology to create/survive in new environment are sufficient to drive evolution forwards.

Witty comment unavailible

And the answer to that question seems to be yes! There are examples where recent inceptive niche construction has brought about evolution in Homo sapiens very recently.

• Domesticating cattle and consuming their milk has prompted lactose tolerance to persist into adulthood within the last 8,000 years.
• In areas of the world technology (amongst other factors) has helped eliminate malaria, sickle cell disease has also disappeared.
• The age of menopause is increasing in many populations, possibly due to niche construction improving the health of the elderly.

All in all, it would seem around 13% of our genome is currently under selection pressures*. So, whilst we may be living in a seemingly artifical environment we have yet to escape the natural process of evolution.

Evolution;
Evolution;
Make and fix and mend;
It’s not yet at an end;
Evolution!

*That does include “purifying selection” where evolution removes deliterious mutations. But ultimatley that is still evolution in action, even if it is not moving us forwards.