How is it so many creatures sharing the same space ...

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can be on such completely different evolutionary tracks? Ever wonder how that works out? People tend to look at Theory Of Evolution in a very general, simplistic way, but when you really consider it, it seems so far fetched. How can so many species in the same area evolve so differently? How do you explain it just by Theory of Evolution alone, not saying that it could be somewhat true...but doesn't it seem like we are missing part of it?

Two main reasons:

1)We don't exactly share the same space. The globe contains a huge number of ecological niches; the ocean floor by thermal vents, inside our intestines, soil, surface of ocean, arctic etc. etc. and even more etc. Different niches drive different adaptations which leads to great diversity. You wouldn't expect a polar bear and an amazon rainforest spider to be similar because they are adapted to such diffferent niches.

2)The timescale for diversification stretches back (about) 3.6 billion years. That's a lot of time for climate changes and extinction events to shape whatever life existed at any given time.

http://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2006.00612.x/full

Thanks Janissy and Narrator!

What I am getting at isn't so much Earth as the small space we all share (one large space, more like, with niches like Janissy typed) and it's easy enough to see how living in a tropical rain forest near the equator is far different than living in the Arctic Circle so I can see how this bio-diverse planet could create varying species but what about let's say the African Savanna and how it produces lions, hyenas, cheetahs, and many prey animals that eat nothing but grass and vegetation. That is what I am getting at. It seems so strange, animals evolving in the same area have such diverse restrictions on what they can eat, how they live, what they look like.

Now look at humans...we are without fur and it's so obvious we crave on an instinctual level, to be covered, like all land mammals tend to be except us and it's like, we are so painfully aware of it at all times. We have no fur. Help! It is a psychological affliction we try to assauge with clothing and it is so obvious we are envious of fur bearing cousins in the worst way. It's evolution's biggest joke. leaving us hairless in a fur clad world.

If you want to look at it from a strictly theological perspective, maybe God punished Adam and Eve in the Garden of Eden for eating from the tree of wisdom by taking away their fur...

That's because you're working with quite a simplistic understanding of the niche.

Imagine if only herbivores had evolved on the Savannah. There would be a huge underexploited resource - nothing was eating all those herbivores! If some of them did start eating other herbivores, they'd have tapped into a source of energy that would give them a huge advantage. The individuals best suited to hunting and eating meat would quickly gain a bigger advantage, and evolution would take hold until you had something like a cat or dog.

That's hopefully quite an easy one to understand. Now think of that on a smaller scale. If an animal specialises in exploiting a food source or another resource which nobody else is using, then it has a huge advantage.


This is cultural. In warmer climates, wearing less clothing is common, particularly where religion isn't influential.

Wearing clothes instead of relying on fur allows us to cool down more easily, keeping our brains at the optimum temperature. It also reduces the thread of parasites like lice. To be honest, I think you've got it back to front - we probably loss our fur as a result of wearing clothes, not vice versa.

You have to wonder, why is it we are the only ones in a vast array of mammals? There are plenty of animals that deal with heat that do not lose their fur to the extent we have.
The part about allowing us to cool down faster makes sense.
Even in warmer climates, people will cover themselves with body makeup from an organic source of some kind. The trend is always toward concealment and most people do cover some parts of themselves with clothing, it just varies how much and it most likely has to do with overall heat and humidity levels.

And then you have people all over the globe harvesting animal hides if they can get away with it, which is an odd thing to do when you think about it, wearing the skin and fur of another species. Even when we don't harvest hides for various reasons, we still attempt to create cloth to cover ourselves from sources such as hemp and cotton.

A lot of our industriousness revolves around clothing. I seriously doubt, if we had fur covering our bodies, this would be the case and what animal that has it wears clothes? So it seems like we started wearing clothes to help us cover ourselves when the fur began to fall, not the other way around, if you go by examples around us. I know most every pet I have doesn't voluntarily wear clothing and the only time I try to clothe any of them is when it gets below freezing out and it's only the dog, not the cats, who would both squirm out of any sweaters in no time flat.

It might have been when mankind started his venture northward away from the equator that he began figuring out how to cover himself but he might have always craved it even in warmer climates just because it's instinctual for a mammal to yearn to be covered. It's like when a species isn't camouflaged into its environment, it knows it stands out. Mice always know they have to go hide behind something or they get captured by cats or dogs or whatever wants to eat them . Same kind of idea here...covering our bodies helps us feel secure.

Competition for the same resources drives diversification. This happens between species (interspecific competition) and within species (intraspecific competition).

http://en.wikipedia.org/wiki/Interspecific_competition




http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2093969/



Imagine that you and 11 people are in a locked room. There are 12 different kinds of food in that room but in limited quantities. If everybody just eats the oranges but leaves all 11 other types of food untouched, you will all go hungry. But if one person eats the oranges while somebody else eats the grapes while you eat the bread and that other guy eats the carrots and so on, then you all get to eat enough. It's like that but on a larger and more complex scale.



Lack of fur looks like a cosmic joke but it must have given our ancestors an advantage or it wouldn't have persisted.

Here are some theories:

http://www.scientificamerican.com/article/latest-theory-human-body-hair/

1)We used to confine ourselves to being near bodies of water to get food (and I suppose also drink). Hair would be a disadvantage in that situation (formerly a semi-popular theory called Aquatic Ape Theory but not much supporting evidence).

2)We lost it as a cooling mechanism so we wouldn't be confined to cooler leafy parts of the jungle as other primates are. The linked article says a flaw in this is that it would still get cold at night, making it a disadvantage, but we apparently mastered fire before we became Homo sapiens so I think a fire at night solves that problem.

3)We lost it as an anti-parasite mechanism and used fire/found or built shelter to take up the slack. Other primates pick parasites off each other and that serves as social bonding but it's even more effective to have the parasites not clinging to your fur in the first place.

When the temperature gets cold enough to kill you, hairlessness is a lot more dangerous than parasites, but we had fully mastered fire, (fur) clothes and shelter-making by the time we were in that position.

It's obvious there's diversification in diet but what I am really interested in is the genesis of all that - we see the results.

Some species are so picky about what they will eat, especially birds...you have to wonder, how did anything ever evolve to eat meat? I know parakeets are ultra picky and won't touch foods other birds will, like bread.

It's really strange that you would see one species ever get to the point where it would start eating other things even if it were over populated in the first place. That's my point since everything started out from the same source pretty much. Or, perhaps, not everything does start from the same source?

You can compare it to humans in a room with a variety of foods only limited. There won't be enough for us all to eat the same things but then again we are omnivores already. It will not matter if we are not eating the same things because all of us will get something.

When you are talking about animals that live pretty much on one type of grass, they won't touch other food types so you could put some of them in a room with oranges and various types of meat they will all die from malnutrition in a relatively short time.

Take a look at the domestic cat, if you deprive them of the meat and certain minerals they need, they won't be healthy and might have a shorter life span. If we put some in a room with meat, grass, and oranges, they wouldn't touch the oranges ever, they would all eat the meat first, then go for the grass but since cats cannot digest it, they would simply vomit it up. They could not live long on the grass alone .

As far as the fur drama goes - wherever there's a mammal some kind of little mite or insect will be there to make it miserable and yet look...they get to keep their fur while we didn't.

^^^^^
We call ourselves omnivores but we can't eat literally everything. If you put us in a locked room with prairie grass and an herbivore, we'll starve unless we eat the herbivore. The herbivore can't eat us but it can eat the grass. We can't eat the grass but we can eat the herbivore.

Why would such dietary specialization develop? Because turning a consumed thing/form of energy into usable nutrients is complicated and takes considerable biological machinery. Nothing can eat everything, not even us even though we call ourselves omnivores. Decisions have to be made (natural selection makes the decisions). Everything alive needs energy to continue being alive but it isn't possible for any one life form to tote around all the biological machinery needed to convert every type of incoming energy into outgoing energy.

You ask "how did anything ever evolve to eat meat?" The answer, simplified, is that meat is a very dense form of energy. Any life form able to capitalize on using that dense form of energy would have an available (with some work) form of long-lasting energy.

Hmm.. I am starting to wonder if I am the only human with fur here.

My cat is not terrified of me, when I get out of the shower but when he sees my wife he HISSES! OH NO! BALD FEmale HUMAN!

SOME humans still have a relatively good amount of fur.

And perhaps that is why I DO NOT FEEL as much need for a security blanket of clothes.

And perhaps that is why I DO NOT own a pair of long pants, even in 18 degree weather.

My legs are furry AND 'the cold never bothered me anyway' (FROZEN DISNEY movie quote, by the way), at least when I AM HEALTHY!..

TRUST ME IT is possible to UN-DOMESTICATE a human being.

AND I FOR ONE, have living proof of it; YES, IN photos!

And it's mightY cool to be WILD AND FREE human being!..

EVEN when it's hot outside..

OH yeah.. I FORGET to mention I do not get hot either, even in 110 'F' heat indices (WITH HUMIDITY) temperature!..

Culture is all about reducing diversity of human beings, overall.

Life is all about diversity, when culture is not such a BIG PART OF THE environmental human equation.

AS a whole humans are now FUNCTIONALLY DISABLED BY the environment of the TEAT OF CULTURE.

AND yes, I CAN PROVE IT, too, by way of empirical measures of strength against age.

More precisely, my legs that lift close TO 900LBS now in NAUTILUS parallel FREE weight leg press at age 54, per 12 reps., as compared to MARINES that cannot begin to do it, in their early twenties, at my local elite military gym.

They do not know how to un-domesticate themselves yet but they are watching and waiting for me to SHOW THEM HOW.

What I meant by omnivore is we can eat the moo, the cluck, the oink, the fish, the rice, the wheat, the millet, the tomato, the arugula, the kale, and on and on and on. If we just ate meat and nothing else, we would run into problems there, too. We need the meat, the grass, the milk, and the rice, if there is any, all in one meal, ideally.

You raise a valid point. If our diet became specialized due to restrictions, as in, only one thing available, it better be something like oatmeal because that would be the only thing we might possibly be able to live on and peasants did, at one time, pretty much live on porridge made from oats.

It just confirms, it would be very difficult for one species to branch off from another and start eating a radically different diet and it would be even harder to go from eating nothing but grass to eating a lot of meat.

The evolution of omnivores like humans, wolves and bears seems

Elephants, naked mole rats, whales, reptiles, amphibians... lots of animals don't have fur. We are an odd species since we evolved a large brain that allowed us to adapt quickly to other environments. Part of this was due to the fact that we evolved in an environment that was itself undergoing rapid change.

I considered elephants, rhinos, hippos. Didn't know about a naked mouse but thought there could have been a hairless mole or something.

Generally, mammals have hair and lots of it. It would be cool to have Chinchilla soft fur. Can you imagine what humans would look like with the same type of fur as chinchilla and would we endanger ourselves and prey on each other if our hides were dangerously soft and luxurious?
That's another point in favor of balding evolution.

"It's freezing? I hadn't noticed."

I wonder if we all have a pair of ancestors way back, or possibly a tribe, when humans were scarcer and in one location, that found something in a rain forest that altered the fur gene in their dna and ingested it. Everyone born after them lacked the full fur effect.

Prolly a fruit- from a tree. The female claimed that a snake recommended it.