Evolution of mammals
Posted on: February 9, 2011 - 11:48pm
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Evolution of mammals
At what point in the evolution of reptiles did they go from laying hard shelled eggs to keeping the egg in the body.
In otherwords how did this happen one generation lays eggs and then the next doesnt that seems kinda strange.
Did it go something like the eggs where getting eaten and the animals that didnt lay eggs reproduced better.
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Evolution does not happen in one generation.
Here is a brief over view from http://www.stanford.edu/group/stanfordbirds/text/essays/Eggs.html
Help me out here, fella. Read a book or two on evolution - one written by a scientist preferably. There are many written for the non expert reader, especially with the recent creationist and intelligent design nonsense going around.
Douglas Futuyma
Donald R. Prothero
Roger Lewin
Robert T. Pennock
And others. Look them up in your local library. Skim through and pick ones that you can understand. Search for related subjects - the reference librarian can help you. Some are textbooks and yeah, have a lot of pure science in them. So pick the ones that are at your level of understanding. We don't all have PhD's in every topic under the sun. And evolution covers a lot of topics. No shame to say - huh, maybe not this one. Is there one a little more for the layman?
Also, browse through www.talkorigins.org
http://www.gondwanaresearchonline.com/General/Index.aspx
Scientific American online - http://www.scientificamerican.com
http://www.talkreason.org
http://www.gate.net/~rwms/EvoEvidence.html
The Smithsonian online
The Natural History Museum online
I got a million of them -- I just searched on the topic I was interested in - sexual reproduction, bird evolution, etc - and then I looked for the ones that were written by scientists and ignored the creationist ones. If the article was over my head, I backed up and went to the next web site that looked promising. Hint: authors who have credentials at accredited universities are usually knowledgeable about the science behind their topic.
edit: fixing the quote, editing out all the html junk
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
CJ I would actually like to say that every single lifeform including me and you are a transistional species correct me if im wrong.
So what im asking is it couldnt knda lay eggs and kinda keep the baby in the body what was the transition from laying eggs to keeping them in the body obvisouly the animal didnt decide.
What seems to happen when a species transitions from egg-laying to live birth is that egg stays inside longer, and the shell becomes thinner, from generation to generation, until what is 'laid' is a flexible membrane containing the young. Even mammals can have this, including humans. Normally the membrane ruptures during the birth process, but it, and the placenta, are what the shell and the other parts of the egg, apart from the embryo itself, progressively evolved into.
This is studied by looking at the many species of reptiles which are at various stages of this transition.
Many reptiles lay eggs with very soft 'shells', so they are somewhere along the line between hard-shelled 'normal' eggs and births inside a very thin membrane, as with mammals, apart from the platypus and echidna.
So that is what changes most obviously, the shell becomes softer and thinner until we no longer recognise it as an egg.
And yes, every single individual is either a transitional form or the end of its line, ie the species is about to go extinct.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
Thanks bob your articulate things well and easy to understand.
I would like to ask you if human toes are a vistigual remant of when we had hands for feet so is it possible that we will eventually lose our toes since we dont use them for anything.
Some species carry their eggs to almost full term before laying them. Such could evolve to birthing eggs inside of the parent species then to the point of giving live birth. There are some mamals that still lay eggs in the Monotreme family whose ancestors could be the transitional species to mammals that give live birth.
“Hokey religions and ancient weapons are no match for a good blaster at your side, kid.”
Well yes and no on that.
Again, evolution does not happen in a single generation. Remember that we really can be thought of as transitional to whatever may be here in a couple million years (assuming that we survive as a group). I would net that you pretty much resemble your parents, who resemble theirs and so on, all the way back to previous individuals that look nothing like us.
So let's consider toes. First off, try being aware of the process of walking the next time you head for the kitchen. We all still use our toes. Today, we use them for balance as we roll over our feet. However, back when we walked on all fours, we did not use them for balance any more than any other quadruped would.
Different quadrupeds use their toes for different things. Horses use them to lift up and shift the leverage of muscles against legs to allow for faster running. Cats are also pretty good runners but they get that from modification of hips and shoulders. Feline toes are a carrier for claws and possibly a sensory organ that helps them to find prey.
Now, is it possible that we will lose our toes in a few dozen million years? Sure but the odds are against it. Most animals that follow the general mammalian body plan still have all the same bones, just repurposed. A whale's front flippers can be shown to have the same bones as are found in both the human hand and the wings of bats. An actual loss of a structure is something that takes a very long time, as far as evolution goes.
An interesting and related fact is that many species of snake still have a set of hips and leg bones which are fully internal. They do seem to have lost whatever bones might have made up the feet of their quadrupedal ancestors, such as a primitive lizard like critter. However, this represents a much longer time scale on the order of hundreds of million years.
Past that, allow me some speculation. Assuming that we are going to continue as a group of critters into the distant future, we do not know what needs our descendants may come by that could result in toes actually becoming larger again. In fact, in keeping with the “tree network” of evolution, by that time, there would likely be many lines of descent with modification. Some may have smaller, nearly nonexistent toes and others may have more fully developed toes.
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Do you have a relative who is diabetic and has had some toes amputated? Then you would know they are still being used while walking. I don't think people are going to lose our toes as long as we have to walk. And I don't see us having technology to the point that we never walk - like in "WALL-E" where all the humans are in scooters. Cute movie.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
As a species, we're at a whole new level of evolution in the sense that natural selection no longer works the same way. For example, the wale's hands have changed into flippers not because they no longer needed the hands, but because, over millions of years the individuals who's hands closer resembled flippers had an advantage and thus were more successful in reproducing. In order for us to loose our toes, there has to be a direct advantage by people with no toes.
So if women decided that they would only have sex with guys with shorter toes, eventually we would loose our toes, or at least morph them into something that we wouldn't recognize as toes. Otherwise odds are we will keep our toes.
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
In addition to what Cj said, placental mammals and marsupials diverge from synapsids quite a while ago (125 mya), before the chicxulub impact at 65 mya.
“A meritocratic society is one in which inequalities of wealth and social position solely reflect the unequal distribution of merit or skills amongst human beings, or are based upon factors beyond human control, for example luck or chance. Such a society is socially just because individuals are judged not by their gender, the colour of their skin or their religion, but according to their talents and willingness to work, or on what Martin Luther King called 'the content of their character'. By extension, social equality is unjust because it treats unequal individuals equally.” "Political Ideologies" by Andrew Heywood (2003)
I thought mutations where random so wanted our bodies change regardless of external pressures.
I know we use our toes for balance but obvisouly our toes have gotten smaller they used to be as long as our fingers so im saying the feet just become a single thing still capable of balance. That seems to be the direction there headed cause its not like girls are looking at guys feet to choose a mate.
Mutations ARE random, without direction.
Selection pressure is anything in the environment which makes some particular variation more likely to lead to successful reproduction.
It is wearing shoes which is most likely to lead to our toes becoming even less prominent, since it reduces the remaining ability of our toes to contribute to stabilizing and otherwise control our walking and running efficiency.
Anything which has no real function tends to gradually whither away due to genetic drift. 'Function' can include anything which has some appeal to the other sex, which often persists because it is some sort of indicator of bodily and genetic 'health', so serves to allow the other sex to chose mates who are more likely to have successful offspring. This choosing is not done consciously in most animals, but instincts which drive mate choice based on some characteristic which is correlated with having more and healthier offspring will itself be selected for.
Our toes don't seem to fit that criterion, especially in modern shoe-wearing culture.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
Let's put this in perspective, let's say a random gene mutation cut your toes length by half. This enabled you to jump twice as high as a regular human, and you became a famous basketball star. This in turn, gets you more ass then a public toilet seat. You become very prolific in this respect and have 20 kids that all carry your gene. They all become famous athletes and in turn pass their gene's to their children. In 10 generations most everyone around around that area will have shorter toes, and furthermore, the shorter the toes, the better the athlete and the more kids that person has. In a few million years we would probably have no toes and jump 4 times as high as a normal human.
Of course having shorter or no toes, if anything limits your ability to jump, so the whole scenario is purely academic, but you get the idea.
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
What happens in evolution is that when nature hits upon something that 'works', as in gives a specimen a great competive advantage, the transition is accelerated. For instance, when humans ancestors started to walk upright, this was such an advantage that those that could not walk upright very well were rapidly obsoleted. This is a reason we don't see many 'transitional forms' in the fossil record.
Taxation is the price we pay for failing to build a civilized society. The higher the tax level, the greater the failure. A centrally planned totalitarian state represents a complete defeat for the civilized world, while a totally voluntary society represents its ultimate success. --Mark Skousen
This is off the topic but I didnt want to start another one.
How come zebras and horses are said to have drifted further apart geneticly than humans and chimps yet they can still reproduce together I find this odd.
Also are their any two primate species that can interbreed.
Here's a good article in wikipedia regarding a zebra hybrid.
http://en.wikipedia.org/wiki/Zebroid
It explains the genetics pretty well and has some good links if you want to follow up on how that works.
The classification 'species' is defined as organisms that are capable of interbreeding. So if two primates were able to interbreed they would be of the same species, the answer to your question is 'mu'
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
At some stage in our early history after we split from the other primates, two of our chromosomes started to show a tendency to stick together, until eventually the line with the joined version became the dominant line leading to us. We still have a very similar genetic sequence overall, but this different chromosome setup makes it more difficult, maybe impossible, to mate successfully with another primate with the old setup.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
That's not to say you shouldn't try... here monkey monkey... I have a banana with your name all over it
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
Yeah, I meant by 'successfully' a mating that resulted in fertilization, but you could still go for a simpler definition of 'success'...
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
I know it is juvenile but eve since he asked about interbreeding primates, all I can think of is some dude chasing a monkey with the intention of having sex with it. I'm so mature... but I'm still laughing when I think about it. lol
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
Humans mating with other primates gives most people the willies. Fertilization would require more than one trial as well. You could get serious jail time making this experiment. An adult chimp is large and dangerous. If she didn't want to, you could be in jail with serious bodily injury from her and no telling how many fellow inmates would want to add to it. "If you like chimps so well, try this!" Also, artificial insemination is out - no review committee is going to allow that experiment. And you would still get jail time.
Bad idea. Move along, nothing to see here.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
Jail time is probably number 10 billion and 1 on my list of reasons of why not to have sex with a chimp. Point well taken though lol.
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
I hate to brake up this mental wankfest of hybridizing humans with other primates, but there is one reason why it will certainly never be feasible: the monoploid dna chains won't fully join up with the dna of a chimp, for example. I suspect this is because of a failure of quantum entanglement (electrons), as was brought up with AE's articles a while back.
Talking monkeys and apes have diverged too long ago to represent any viable hybridization oppurtunities.
“A meritocratic society is one in which inequalities of wealth and social position solely reflect the unequal distribution of merit or skills amongst human beings, or are based upon factors beyond human control, for example luck or chance. Such a society is socially just because individuals are judged not by their gender, the colour of their skin or their religion, but according to their talents and willingness to work, or on what Martin Luther King called 'the content of their character'. By extension, social equality is unjust because it treats unequal individuals equally.” "Political Ideologies" by Andrew Heywood (2003)
You jest of course, I hope. I still like my mental image of some guy chasing a chimp, it's more crude, but much funnier.
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
Talking monkeys and apes? Someone has been watching way too much 'Planet of the Apes'. wtf? lol
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
No, I don't see any personal attraction to chimps.
But what is it with these farmers and their cows and sheep ?
Or this thing that women seem to have for horses ?
Rock103, the local radio station here that specialized in crude humor and classic rock tunes, often times brings up obscure laws on the books in Tennessee that were never repealed or that just seem really odd.
But anyway, on the way to work the other morning, I heard it said, that it is against the law here in the State of Tennessee for a single man to purchase a sheep. Now, why would the lawmakers wish to come up with a legislature like that ?
“It is proof of a base and low mind for one to wish to think with the masses or majority, merely because the majority is the majority. Truth does not change because it is, or is not, believed by a majority of the people.”
― Giordano Bruno
The implications are hilarious. You should find that law and make a blog out of it, it's freaking funny.
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
As somewhat of a "snake expert" (more of a keeping and handling snake expert, kept snakes all my life) I would just like to add that just in the snake species of reptiles alone their are egg-laying and live bearing snakes. For example all python subspecies lay eggs but all boa subspecies bear their young live, yet both belong to the same family of snakes = Boidae. The python eggs are very soft and delicate nothing like a birds egg, the boa young ofcourse are kept in somewhat of an "egg" inside the body. It is not to difficult to see how the process works, and how it can slowly go from one to the other in time.
That is also what people said about letting different races interbreed.
And what is so great about the status quo? We let teenagers breed under the influence of hormones, alcohol and other drugs. Men knock up women not because they will be a good parent but because they get women high on romance, music, chocolate and other drugs. We let people continue breeding and overpopulating the planet leading to more poverty, war and environmental damage. We can't have mandatory birth control because the right to breed is sacred.
So what is so great about the current system? Doesn't it lead to a ton of suffering?
We hold other primates in captivity(because we've destroyed all their natural habitats) and only let them breed for our amusement or profit. There is nothing rational about the current system of primate breeding. Also jail time isn't going to stop people if their are profits to be made.
Taxation is the price we pay for failing to build a civilized society. The higher the tax level, the greater the failure. A centrally planned totalitarian state represents a complete defeat for the civilized world, while a totally voluntary society represents its ultimate success. --Mark Skousen
Fine, great. You have my permission for what it's worth.
Personally, I wouldn't risk it.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
S/he isn't happy, that's for sure!
“A meritocratic society is one in which inequalities of wealth and social position solely reflect the unequal distribution of merit or skills amongst human beings, or are based upon factors beyond human control, for example luck or chance. Such a society is socially just because individuals are judged not by their gender, the colour of their skin or their religion, but according to their talents and willingness to work, or on what Martin Luther King called 'the content of their character'. By extension, social equality is unjust because it treats unequal individuals equally.” "Political Ideologies" by Andrew Heywood (2003)
Well, not to burst anyone's bubble but this really bizarre experiment has actually be done dozens of times. It has never worked. Probably because of the chromosomal difference that BobSpence already noted.
http://en.wikipedia.org/wiki/Humanzee#The_Ivanov_experiments
Apart from that, there is also an answer as to why what seem to be different species can successfully mate and in some cases even bear fertile offspring. Part of the answer lies in the fact that long before Linnaeus proposed inability to breed successfully as a species distinction, it was already well known that that was only approximate.
Really, the ancient Greeks knew well that if a horse was bred with a donkey, they would get offsping that could do more work than a donkey and not need as much food as a horse. They are called mules. They are also almost always sterile but an occasional fertile mule has been documented.
A more complete answer would require asking the question of just how different do two populations have to be before they can no longer interbreed?
I think it safe to say that we all know that any two varieties of dog can interbreed successfully, at least for the most part (I doubt that it would be physically reasonable for a male great dane to mate with a female chihuahua but on genetic grounds, the reverse should be possible). That and there are some few scattered populations of dog/wolf hybrids that are viable breeding colonies.
Then there are what are known as “ring populations”. The notable example is the northern hemisphere seagull. Follow me on this:
However, the New England populations are not fertile with the Icelandic populations.
Then too, sometimes the populations are separated by rather less obvious geographical boundaries and yet remain fertile to some degree.
Cats show this property fairly well. The genetic evidence is basically in that the common ancestor of all domestic cats is a wild cat from the Mediterranean coast of Africa. Domestic cats have been successfully bred with both the African Serval and the Asian snow leopard. In both cases, the males tend to be sterile and the females have to bred with domestic cats for five generations before fertile males develop.
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You can lose toes 2-5 with little to no problem. But the hallux has HUGE implications on walking and balance. As in, you would have to completely alter your gait pattern (and probably use cane/crutch/walker) without the big toe(s). So women aren't looking at toes... but if you are shuffling around on your heels and you can't run I don't think you are going to be incredibly successful in entering the gene pool.
The male dog has to be able to "tie" the female. A male chihuahua is not large enough to accomplish this with a giant breed like a Great Dane.
All canids can interbreed and have fertile offspring. "Red wolves" in the US South east are actually a gray wolf x coyote.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
How come the peppered moth example for evolution is cited like its going to convinvce someone who doesnt understand evolution I admit I dont understand it either like for example how come some were black and some where white and the ones that were black survived because it was good camofluoge so how come some werent born with blue skin or green skin and for that matter how come humans arent born with red skin or blue skin or any other color
I meant to say used not cited.
We're the hunters not the hunted(except by other humans) and we can build the camofluoge we need.
Taxation is the price we pay for failing to build a civilized society. The higher the tax level, the greater the failure. A centrally planned totalitarian state represents a complete defeat for the civilized world, while a totally voluntary society represents its ultimate success. --Mark Skousen
I know we dont need to change im saying why arent their random mutation s like that if a white moth can give birth that seems preety drastic dont you think like out of the blue.
Read this article
http://en.wikipedia.org/wiki/Peppered_moth_evolution
"Don't seek these laws to understand. Only the mad can comprehend..." -- George Cosbuc
It is NOT out of the blue. Mutations are not - strictly speaking - totally random. Why? Because you can't flip a coin and stick any old molecule in the DNA. The chemistry dictates what mutations are possible.
Wiki may not be the absolute best source of information, but this is okay if much simplified. http://en.wikipedia.org/wiki/Dna
Note - adenine MUST bond with thymine. Guanine MUST bond with cytosine. Urasil often replaces thymine in RNA, but is never found in DNA.
So, if there is a change in coloration of an animal (human or moth), the melanin proteins must be changed, but they can not be changed into something they are not. It is why horticulturists have been trying to breed a truly blue rose for years and can only get lavender at best. They will have to do some genetic splicing to insert the proteins for blue that are not in the rose genome.
"Blue" people exist - they have a genetic deformity.
http://en.wikipedia.org/wiki/Blue_People_of_Kentucky#Carriers
The last sentence means their tissues can rot from lack of oxygen.
So, why do we have genes in the population that are not good for you? Because they don't affect whether you can have children. If your children can have children, even if they die shortly after having children, your (and their) genes will be carried into future generations. If you make it to breeding age, that is all that is necessary for your genes to be at worse, a "neutral" mutation. A negative mutation is one that prevents you from having children. A positive mutation is one that helps you have more children.
Back to moths. A slightly darker moth was able to survive better, and that moth mated with the other survivors who were also slightly darker. In any population - unless their diversity is very limited, remember the cheetahs - there is a lot of variability. People are all "people" colored, but you have to admit, we aren't all the exact same shade. Moths are the same - some are already darker, some already lighter in color. The dark moths would survive better in shadier places than the light moths. The light moths would survive better in the sun. Remember, all they have to do is live long enough to have offspring and those genes are in the next generation.
Also, as the air quality has improved, the lighter colored moths are gradually becoming the dominant color again. Evolution at work.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
That makes me think if every male black person only got with a chinese woman and every chinese male only got with a black woman after so many generations wouldnt there no longer be a difference wouldnt they be a single race?
There is no such thing as race. See "The Journey of Man" by Spencer Wells either as a PBS special on dvd or the book.
http://www.amazon.com/s/ref=nb_sb_ss_i_4_32?url=search-alias%3Daps&field-keywords=the+journey+of+man+spencer+wells&x=0&y=0&sprefix...
People have a number of genetic disorders that can cause skin color splotches. Here is one. http://ghr.nlm.nih.gov/condition/vitiligo Browsing the site is sort of interesting - for so called "perfect" creations "made in God's image" humans sure are subject to a lot of genetic disorders.
And again, Wiki is not too awful bad for a resource: http://en.wikipedia.org/wiki/Human_skin_color
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
I dont get how evolution programs our brains for example they say that its in an ants nature to behave the way that it does. Could someone word this in a way that I can understand?
IM asking because we all have a sense of fairness and compassion but know one had to teach us that or at least it seems like it.
Ants perhaps started as a single type, but over time mutations within a even species caused some ants to be more tailored for specific tasks creating the polymorphism we see in ants today. The behavior that is apparently "programmed" is because of the specialized evolution for a specific task.
“Hokey religions and ancient weapons are no match for a good blaster at your side, kid.”
Fairness - that is the idea of equality - looks to be ingrained. Monkeys count - dogs count. Hey, he got one more than I did!!! This is probably necessary for survival. Monkeys, dogs, and people all share, too. It isn't compassion, it is because we are all social species. We can not survive on our own. We must have a group - to help raise, protect and feed children, puppies, or infants.
Compassion is also related to being a social species. Having the mirror neurons - those neurons that allow you to mirror the feelings of another member of your species - to have empathy - helps keep the group cohesive. Which helps with raising those offspring. Sociopaths - those lacking the mirror neurons or with hormonal imbalances - are not viable group members, having no skills for raising offspring. If a sociopath happens to be a great hunter, they won't share, and so they don't contribute. And so evolutionarily have no value to the group.
I once looked up Mountain Men. You know, Jeremiah Johnson and other trappers. They did not go out during the winter and they went out in groups, not alone. You are safer in a group. There are other people to help with the camp chores. There is someone to talk to. Jeremiah Johnson spent only the one winter out by himself. And after he got out in the spring, he never went out in the mountains again - alone or in a group, summer or winter.
-- I feel so much better since I stopped trying to believe.
"We are entitled to our own opinions. We're not entitled to our own facts"- Al Franken
"If death isn't sweet oblivion, I will be severely disappointed" - Ruth M.
I guess what I am saying is what are the theories on how these came about> If it wasn;t for the smell and taste of food we wouldnt eat it and if we dont eat we get hungery which makes us it things that are less tasty in order to stay alive. If we didnt become extremely aroused by the opposite sex we wouldnt want to do it and thus we wouldnt reproduce. If we didnt have emotions we wouldnt bother to do anything defend our territory and loved ones or fight back when we get hit. If we didnt feel tired and relaxed we wouldnt go to sleep. If we didnt feel fear we wouldnt bother trying to stay alive and run from danger. If we didnt feel pain we would do things that were destructive to our body and not know it and eventually die.
All these things seem to convient and I really want to understand a natural explanation for them and what were the stages in their development. I'm sure there is a way to break it down just like a musical instrument has a complex sound wave but can be broken down into individual sine waves at different amplitudes.
I think you have it backwards.
Those variants which weren't attracted to the more nutritious food, or adequately driven by their built-in urges to have sex, or run away from danger, simply wouldn't survive anywhere near as well. That is really basic 'natural selection', that would have started way-back in the emergence of life, and been pretty strongly selected for ever since. It ain't no mystery that I can see.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
thats what I was saying if it wasn't for those things no creature would be here. I am asking how they came about because the first living things did not have these qualities? When did food come into the picture?
The initial formation of self-replicating molecules was the starting point of life.
Those which happened to self-replicate more readily would obviously quickly come to dominate that early environment. That was what represented an 'urge' for reproduction and a 'preference ' for the most useful and available resources at that stage. So they were there at the beginning, but only as basic chemical properties.
As more complex forms came to form over the millions of years of step-by-step change, those 'urges' and 'preferences' themselves evolved into more complicated mechanisms under the unavoidable pressure of 'natural selection', ensuring that the ones which fed and reproduced most effectively tended to dominate.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
Yeah I think someone asked this question before what was the reason for organisms getting as big as they did why move past simple cells?
Simply because they could.
There was nothing to stop them.
Just like a gas will expand to fill the available space of whatever container it is in.
No purpose, just the consequence of the random nature of variation.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology