Friday, December 20, 2013

why do the sloths come down to poop?

Saturday, November 30, 2013

life goes on...

Life goes on...

[watch in full screen]

What I meant however, was to cease the thought that our (human) evolution has stopped...we are simply just in our niche right now...

Take care. :)

Sunday, September 29, 2013

so why sleep?

Earlier I thought it was because of the earth's rotation, and day-night cycle. But then I realized, the very first animals evolved in the deep oceans where sunlight was devoid.

What then could the reason be?

Actually at this point of time its very difficult to theorize because we don't have a proper scientific understanding of how sleep happens to other species on earth. When we sleep we become immobile. We don't have a sense of touch or any normal audio that is going on around us. Its as if our brain shuts down its vital functioning.

We know what lack of sleep can do to us. It can cause disorientation, make us less-responsive to normal auditory stimuli, and, many other cognitive problems. These patterns of problems can be observed on other species too. There are species of fruit flies which were subjected to experiments which disrupted their normal "rest cycle". It was found that fruit files which did sleep were able to locate food faster, whereas those that didn't get enough sleep couldn't find it fast enough.

There is an evidence that sleep is necessary for proper development of the body as well as the brain. The brain tries to repair connections or even make new ones after it "shuts down". So I suppose this is why infants spend most of the time sleeping.

But how can we explain it in terms of evolution and natural selection?

I suppose the answer to that can be formulated as follows:

Growth or development in any life form is a natural process. But I suppose a "rest phase" is necessary here, because that ensures a healthy development. Any life form in its normal growth or development, if it does not have a "rest phase", its doomed to fail and will be less capable of surviving long enough. And being awake does need more energy, and more maintenance.

So now you can bring natural selection into the solution. So those species which took to this pattern of growth and development survived and flourished.

You may very well ask, there are animals that don't have brains; do they require sleep?

This is almost like suggesting that the brain is the organ responsible for sleep. If so why don't our brains go to sleep keeping all other functions working as necessary? I can't imagine how a human would be in such a condition. But the general understanding should be, if the brain "rests" so does the body. One or the other organs need functioning, others don't. For e.g. our muscles don't need to move so much so they are relaxed.

To a degree this is a kind of symbiosis. This kind of a symbiosis is necessary for healthy living and also to minimize energy consumption.

I really have quoted articles I've read, or videos I've seen on the subject. Research in sleep is still in a study and observe phase. Scientists have not extensively studies "sleep" in other species like they have done on their own species.

However, often I do come across articles and they will be tied to this blog post, as and when I come across some interesting articles. You can find a list of artefacts tied to this article below:

You can keep track of interesting stuff over at my google+ page. Please follow that page if you want regular updates. If you do have questions yourself, just drop in an email to ask [dot] deostroll [at] gmail [dot] com. You can also post a question directly at and let me know about it. Would be happy to answer or review answers.

Saturday, July 27, 2013

The explosive past...

David Attenborough's documentaries are “visionary”. The inspiration behind writing this post comes from one of his documentary series called the Origins of Life. It kind of attempts to explain some of the common features almost all the animal species have. Most of these features stare at our faces; I mean, we experience them everyday. But we are not there to appreciate it...we just let it pass like an average ordinary day.

But this post is not about the average ordinary day either...Scientists, when they study fossils, theorize with the little evidence they get. They try to imagine how that particular species would have lived. Why they had the body plan that they had. What kind of advantage did that body plan give them. Its their theories which are truly illuminating. Much of life that is today we owe to these species.

Fossil science may not be my niche. However, facts you get to learn about various things when you discover a fossil are great. We try to answer questions like:
  • How come this fossil is perfectly preserved?
  • What sort of environmental conditions lead to this?
  • How the earth's terrain was at that point of time? I.e. Its geology.
  • What are the characteristics of that particular geology which lead to the preservation?
  • What period this fossil belonged to? (Carbon dating, geological era).
Answering these questions give us a clue as to how the earth's surrounding could have been. Such evidences are corroborated with the other fossils they collect around that area or site. These again are basically theories. Then using these theories we try to figure so many other aspects of the fossil.
  • How it lived?
  • The shape it had?
  • The unique bizzare features it had.
  • Why those features where there in the first place...? (natural selection).
I'd normally want to type it all. However, I think these best way to communicate the fascination is via presentation slides.

So enter the Cambrain era...

Saturday, June 15, 2013

the time travel we really want...

Almost everyone would have seen the movie series called "Back to the Future". In fact in the second part is where the hero, Marty, meets his teenage mother in the past, and she even falls in love with him. Very fascinating sci-fi movie. And it made the blockbusters too...

...but it gave us the wrong idea.

But why talk about time travel when this blog until now was talking about humans and the way of life, and other related but abstract things?

The short version: although we may not want to admit it, we are eternally searching for meaning and purpose of our lives, our existence - the universe. This is humanity. You can take a look at all major religions in the world today and see what they preach if you are still not convinced.

Time travel is possible. But it requires massive energy. Such scales of energy are only found near stars and black holes. Scientists equate the notion of time to that of a meandering river. There can be whirlpools inside it along the way; or the river itself can fork.

Time that forks simply means that there can be an alternate reality. The alternate reality part can be best understood by looking up a famous thought experiment called Schrodinger's cat. You'd find a link to a collection of videos and other articles in the end - one of then explains this idea.

So what is the future?

You can say its an event which takes place at time which is ahead of the one you are in now. But, behind the scenes, there are always factors or related events, which must produce outcomes that support the possibility of that event being successfully observed. For e.g. a plane taking-off is an event. The weather in the airport is an influencing factor. If its favourable the plane can take-off. The plane can take-off during a bad weather also. That is also a possibility. There can be engine failure at a critical time, like when its on the runway and on the verge of take-off. This is also a possibility. But the plane doesn't take-off - the event in that sense is unsuccessful.

But around that event there are many outcomes. The outcomes decide if we'd be able to successfully observe that event or not. These multitude of outcomes can be fit into a huge equation of probability, where the probability is simply computed as the probability of that specific sub-event happening successfully or not.

This is extremely complex to model, and those sub-events can drill down to the quantum scale theoretically speaking. Here things are even more complex.

So what does this all say?

The future like all other events is an event. That event has a lot of sub-events associated with it. From the perspective of the event being successful, all those sub-events should have supporting outcomes. Its an astronomical number of combinations which has to be correctly supported. This is what I would call Fate. (I know that word is taken, but bear with me).

And now time travel: everyone out there wish they'd want to go back in time, fix things and have a life changing future. The riddle is, how does one plan on getting to the exact same state of events as that of the desired point in the past. Isn't knowledge of all those events required?

So well, time travel is possible, technologically impractical, and as of today, not really reliable. :)

You can never change the past, but you can control your future, and have faith in the fact that you would.

Interesting links related to this post:

Wednesday, May 01, 2013

don't leave the grieved one behind...

Originally derived inspiration to write this while I was creating my previous post.

In almost all of the cultures today funerals are conducted when someone passes away. This is a phenomenon which is as old as humanity itself. They are conducted in different styles; each of them are closely connected to religious beliefs that that culture shares.

I recommend that those who have lost someone dear recently not hang around to read the remainder of this post.

Burial practices!

Every popular human civilization that ever existed on earth had them. And because of cultural diversity, these practises were all different from other civilizations. For the human species almost all practices show a pattern wherein the body of the deceased individual is ornate with food, or, clothing, jewels, etc, and then disposed.

The existence of such practices kind of proves the fact that the human species are aware of death. But other animals in the wild do exhibit such awareness!

However, the degree to which they exhibit awareness is somewhat confusing or misleading. The above picture shows a bird "mourning" the death of its mate. But the fact is we don't know if its really mourning, because mourning is what we "humans" would do. When "humans" try to empathize with the above picture, what we'd probably do is mourn.

The psychological term for this behaviour is pareidolia. However, people might also call this as a side effect of anthropomorphism. This is one of the reasons why we'd always unconsciously associate an emotion with the following pic:

Getting back on track: imagine that the victim bird in the earlier pic was the victim of a stampede or an attack by a predator. Imagine that the threat that killed the bird still persists in some way; the predator is somewhat nearby, or the stampede hasn't ended. It is actually dangerous for the other bird to linger around. And staying around the deceased individual wouldn't help either - because it can decompose and increase the chances of the other bird contracting diseases.

These arguments apply to our primitive evolutionary counterparts too. But then why do we still have such practices when, you objectively look at it, it is kind of disadvantageous to the survival of the individual?

To answer this puzzle: you can draw references by observing what actually happens during funerals and figure it out. But fundamentally you'd need to understand the dynamics of group survival. In other words, what it means surviving in a "pack".

Pack formations had the distinct advantage of showing up in numbers. Hunting in numbers proved relatively better success rates in getting food. Similarly warding off threats also was relatively successful when there were more individuals to defend. So hence pack formations were a kind of behaviour that got naturally selected. But pack formations slowly lead to socialization between individuals. These kind of socializations kind of make it difficult to answer one question...why we mourn?

Now imagine a small pack. Say that only two individuals know how to hunt; assume they were relatively successful at it too. Now what happens to one individual when the other one has met with some misfortune and passes away? For whatever reason he/she might mourn.

But what about the other surviving members in the group?

Even they might mourn, but what they'd really need is the realization that they need to move on in order to survive. So one of them takes the call, tries to motivate the other to move on. Such sort of gestures are really crucial if the group's primary mode of survival was hunting. Previously two individuals were skilled at it; now one only of them remains. If the skilled individual was the one which was mourning, the whole group becomes challenged in one sense. Hence one of the members in the group takes the responsibility of bringing the grieved one out of shock, so that their chances of survival are relatively increased. Hence they may actually perform simple rituals to pay respect to the deceased individual. The primary focus of such an act was to make everyone move on with surviving.

Over time these simple rituals became more complicated because the number of individuals in the group increased...the population exploded...people settled down with the discovery of agriculture...societies formed...politics emerged...and then history happened.

Interesting links associated with this post:

Monday, April 29, 2013

the symbolism of tears

Why do we shed tears when we are sad?

Our eyes fill with tears when we cut up onions, or, when exposed to dust, etc. The function of tears here is to protect the eye surface.

But why does our eyes fill up with tears when we are hurt, or, feel sad, etc?

There is an emotional aspect to it, but before we go there, just get familiar with scenarios where our eyes actually fill up with tears.

1. While suffering from intense physical injury or a wound

If you had a nascent mouth ulcer and you purposefully put a pinch of salt over it, your eyes with probably start to fill up with tears...

Similarly any physical injury, like a hand fracture, etc could induce tears in the eyes.

Digressing a bit: infants know only one thing to do when they want something, or, when they know something is wrong – cry. And when they do, even their eyes also fill up with tears sometimes. Of course for the case of infants, the pitch with which they cry, the tone, etc are features that got naturally selected to evoke empathy in the person attending the infant. They actually call out for the person's help. The help that the infant receives will again be dependent on how fit that person is to provide to the child. (But that is a subject of another matter).

Say when the infant is grown up a bit and able to see and react to the surroundings; what would it do when it is approached by a predator, but the predator has not seen it yet. The infant can cry, but that would defeat the infant's chances of survival. So the infant eyes starts to fill up with tears first. Now for the mother/father, this is a sign that the infant is probably in danger, and hence the mother will take some actions to save her offspring.

Another theory (which is called the white flag theory) kind of says that in a fight, if one person happens to cry, its a sign of surrender or helplessness. The tears which the loser shed in this scenario is again to invoke empathy in the aggressor, so that the aggressor doesn't kill/punish the other individual.

In all these examples the function of tears are merely symbolic – they point to the fact that the individual is suffering from something, and its intended purpose here is to evoke empathy, and expect help from the other individual so that the subject's chances of survival relatively increases.

So in these situations relative success is only there when there are other individuals there capable of feeling empathy – in short people/individuals should be around the victim and should be willing to help.

2. While experiencing sadness

This is mainly a phenomenon common with the human species. As before tears symbolize suffering, but the suffering is something hard to understand in the case of sadness – it depends on the situation. When a child loses his parent he/she cries because of various reasons:
a) the parent's affection to the child that the child has gotten accustomed to...when the parent has expired the loss of affection is something of a shock for the child. This is purely psychological because it matters to what degree the child is aware of the affection, mental maturity, etc.
b) sometimes its just a gloomy outlook of the child's chances of survival itself since the protecting member has passed away. (But in this context, the child should again be mature enough to understand it).

There can be many reasons; it depends on the situation. The “suffering” is not exactly loneliness, but we shall call it so – since loneliness is something which reduces the chances of the individual's survival. The usage of the word loneliness encompasses a much larger scope that what is actually defined in the English language in this context.

It is a common pattern in most of the mammalian species which used to hunt or forage for food. Living in groups helped survival of the individual and the group collectively.

3. Tears appear when we feel empathy sometimes

Our eyes fill with tears when we've watched a tragic movie or read about a tragic love story. Sometimes when we hear some exceptional piece of musical composition, or an inspirational speech, our eyes fill with tears. The function of tears where is more of an empathetic symbolism – it is sometimes equivalent to saying I know because I feel the same way...

Last but not least...

The reason I write this post is because someone tweeted about it. I read the article and found my inspiration. Tears have a symbolic meaning usually. But for it to be symbolic there must be people to observe it and be able to take action on it; else the purpose of tears is lost. With this fact, please bear that when you happen to cry while all alone, it doesn't help at all, because the tear-ing incidentally happens to have evolved for a kind of social purpose meant to increase the individual's survival.

You can find links related to this post here:

Saturday, March 23, 2013

the reason for enjoying music

The inspiration for this post comes from an interesting question on I am only mentioning it here to give you an idea how to think "evolutionary psychology".

Does listening to music enhance our survival?
Does it help us pass on our genes to the next generation?
Does it help in avoiding immediate threats?

The answer to all 3 questions are No!

For the humans music is a form of expression and a way to communicate. It is an art. For birds its a mating ritual. Most species on earth has evolved a sense of hearing - they can listen to sounds and take an action; but they evolved for the purpose of keeping the individual alive.

For e.g. when we walk alone through a woody forest and we hear some rumbling in the bushes our first impulse is to get startled and flee. Suppose you are thirsty and stuck in a forest and you hear a stream of flowing water, you get a bit excited and advanced to the source of sound with the hope of quenching your thirst.

But what can we conclude about how our brain works from the above two scenarios?

The brain has so many rules already wired. They are only there to keep us ticking.

This "pre-wiring" is a very ubiquitous. It is present in almost every specie living today on earth. We can explain in terms of the need for a species or an individual in a specie to survive. But what about why we enjoy music? It is currently a very popular phenomenon. But we've just established that we can't explain it in terms of survival. Then why is it popular?

Not everything can be explained with the idea of survival. Sometimes certain behavior simply exist because such "rules" exist in our brains or in a more general sense in our living systems. And when the species attains some level of evolutionary stability or maturity they flaunt with it; they simply use these behaviors to maximize their chances of reproductive success. These behaviors are in a sense "naturally selected".

This does not mean people who play musical instruments are constantly on the lookout for partners. This does not mean that people who go to rock concerts or an opera are looking out for suitable partners to mate with. Some go to enjoy the art form. Some go to have a good time with friends. Of course some do go out for seeking partners to mate with. Some don't go. Some have even more vile intents. All of this simply says our species is increasingly selective for the better or worse. That's all.

Well, this is all I have today. But I hope you are at least a bit inspired to think evolution (if not evolutionary psychology). Happy figuring out life...

You can find interesting links related to this blog here

Monday, March 18, 2013

The odd clean up

In any blog, a post like this might seem odd. Because I am writing this post to clean up stuff lying around this web page. There are link rolls, text saying how you should read my blogs, history of posts, etc etc. I just decided to go with minimal stuff. Hence all those content which used to be the right side will now appear as part of this post. While I am doing that, why not I share some few bits about this blog too...

So why am I doing this blog?

I am no biology student or any active academic scholar of biological or evolutionary sciences. But I am still discovering so many facets of human life, and all life on earth. I share as I learn with the hope that someday we all could have a better sense of life on earth.

How long have I been blogging here?

Well, pretty long enough. In fact the very first post of this blog says that I have kind of revived this blog. So I suppose you have to take it back to probably 1 or 1.5 years before 2005. Even I can't remember exactly when I started. However, I began taking an active interest into human evolution  way back in my school days - 11th or 12th std.

For how long do I plan to keep writing/blogging?

I am actively looking at other ways to reach out. Blogging is just one way, but not the ideal way. The best mode of sharing what I discover is through conferences, conventions, group gatherings, or, interviews where I can get to interact with people real-time. So I'll blog or do whatever I have to as long as I want to.

Why don't I just write a book or something?

It simply doesn't seem like a monetarily sound idea. Yes I'd want income out of selling copies, but with all the piracy going on I rather not do it. However I would love to write. I do not view this piracy as an evil thing; to some degree the society does benefit from it.

So, if its not writing books, blogging is the next best thing.

So what stuff do I share around here?

Primarily my thoughts on life on earth in general. Most of the time its about our species. Honestly (and in good probability) there is no other species "our species" can relate to (living or extinct). The questions I am fascinated with are simple but hard to scientifically or evolutionarily explain:
  • What is love? Why is it our species show an abundance of exhibiting this phenomenon? Why do we do the things we do when we are actually in love? 
  • Religion? Why is it so common? 
  • Why would a crawling infant, who has never seen a snake be afraid when he/she actually saw one? 
These kind of questions are bizarre. They are not meant to help you figure out your problems with life, the way you feel, or, how others feel about various things connected to your own life or otherwise...but if you are in a sort of mental block with life...the stuff here, or the way I try to answer stuff here would definitely help you move on with least in a relatively better way.

How to find stuff thats already here?


Most of the posts are tagged with keywords. They will help you locate posts out here. If you are looking for a particular article I would have linked to in one or more of my posts keep a tab on my delicious link rolls.

Any interesting article I read which is related to the interest I share our here I tag it with the word my delicious links can be accessed as follows:

For new readers: how to read this blog

Expecting people who land here to read everything I've ever written is farce. In fact you don't have to read everything. Here are some posts which I think you might find interesting...

The better way to get you up-to-speed with this blog is to have some sort of an interactive session - a conference, meet up, gathering, etc. If you feel interested in the blog after reading the above posts I have linked to, then I think its safe to meet up. :)

Okay, now I do have a do I ask?

If you are still reading all this I gotta give you credit. But I am not the expert at finding answers to all kinds of questions. Its not about finding an answer; its about sharing what you learn in a diplomatic way. So having said all that I'd advise you to follow these steps:
  1. Google. Because you may be surprised with whats out there...
  2. Try searching or joining discussion groups which would relate to your topic. I used to regularly discuss at
  3. Post your question on Quora. Someone out there will definitely answer. But be polite and clear with what you are trying to ask.
  4. If none of the above work, ask me. Quora has a feature by which you can ask other people to answer a question - use it...if you feel your question needs a much less publicity then email me at:
    ask [dot] deostroll [at] gmail [dot] com

Saturday, March 16, 2013


I am a somewhat inspired to write today because of what my folks at home think about the concept. But in reality probably everyone has the same notion. We only live in the boundaries of what our fate defines. Some believe its written, and belief in that fact provides sense and purpose to life. However, many religious/cultural beliefs say that it is our responsibility to understand what is the purpose of life – or more precisely what is the purpose of your existence in life?

Not all cultures/religions share the same idea of fate – and even if they do its not in the same fashion. Hinduism and Buddhism attaches importance to this idea through a term called karma – the sum of all actions – what the individual has done, what he/she is currently doing, and what he/she is will do. Christianity and Islam does recognize fate but links everything to a supreme being – God. Whatever happens its all according to the Divine Plan or in accordance with the Will of God (or Allah).

The more I think about popular religions the more I see a cause, a purpose why a particular belief is there. It somewhat paints a picture of an ancient society. Sometimes the reasons may be very prosaic; other times it may be controversial. Whatever the nature of that reason be, in a socio-evolutionary sense, why do we “have” some notion about "fate"? Was it something useful to a group and hence survival?

Well, yes!!!

The answer to the last bit is not something you want to have tea with...but to a degree it relates to our species just “carrying on with their lives”...getting on with it...

Now why is “carrying on” part important?

Well, its not really important – its just that you would not be reading this post otherwise, and I would not have even written it! :)

And before I conclude this blog post, I have my own idea of fate, but I rather choose not to express it in words. Instead I'll share a video about a very common phenomenon associated with the way we human beings reproduce – fertilization – it should give you an idea.

Links to articles related with this post:

Sunday, March 10, 2013


What are the most celebrated events all over the world?

If I were to ask you this the answers I'd expect are: New Year, Christmas, and probably a host of national holidays. But you do know every second you breathe someone dies, and someone is born. Perhaps I would have misguided you by using the word “celebrated”. There is always some “sense” with which I use words out here. In my defense, other popular personalities use it too – like Shakespear, Hemingway, or Tennyson. Else English Literature would have been extinct a long time ago.

Childbirth and Death are really old phenomenons; older than marriage. Many cultures hold rituals to commemorate both. Scientifically speaking people are born in the same manner, and they die in the same manner (more or less) (biologically speaking). Then why would different cultures have different rituals for each of these?

The fact we must importantly observe here is that a “culture” almost always “has” a ritual. Why?! What is the necessity? Scientists who have observed animals say that they do exhibit some crude form ritual practice. This may also be a basic answer as to why "we" have these ritual practices. But most importantly this sheds light to the fact that we are an emotional species. Some scientists today quote this as one of the reasons to explain why religions, cultures, and all those sacred religious practices exist. Its hard to imagine what would have happened if we were not emotional beings. This was a necessary part in our survival saga.

Here are a bundle of links to articles related to this article.