Originally Posted by Sabra Kusabana
I had planned to wait to continue this debate till the weekend, but as my husband is asleep I'll attempt to compose a proper response before he wakes, as quite simply I'd rather waste my hours with him then on any kind of debate. I'll try to be less collective in my information representation this time and more specific to the counter points that have been put forth. I don't like quoting long posts, but I'll try to be aware of each point I address so that I can try to be complete in my responses. I'll try to be much clearer in my meanings as well.
"If we all come from a common ancestor, it would have had to possess every single gene and trait that has ever existed, making it more than a simple bacterium." Not necessarily true, but also not impossible. Beyond that such a thing could have existed, and still have been a mere bacteria. Let me explain. A gene is only expressed in an organism if their RNA reads it. An organism can possess any gene that exist, but if it's RNA does not read it, it won't be expressed, and thus the creature could have every conceivable gene and never express them. Proof of this ability to have a gene and not show it exists all over, but there is a striking case of it in Jellyfish and Anemones. Both types of creature have the gene for a bilateral body structure, one with two sides; however, both creatures often appear with a radial body structure, rounded. There are some jellies which even show the gene in only a part of their bodies, some jellies have sails, small structures that they raise with water pressure and use to propel themselves with aid of the winds, these sails have fronts and backs they are bilateral. While these jellies have such sails some of the species that have them are still radial in all other aspects of their structure, proof that a gene can even be partially expressed in a species and completely suppressed in others of the same genesis. So why could a bacterium not have all the possible combinations and simply not express them?
One of the perpetual issues taken with evolution is the difference between micro and macro evolutionary types. One has been proven, beyond doubt, the other has not. The thing about the macro version is that it has not been witnessed in the way we desire it to be. There have been observations of new sub-species of organisms being produced, even acknowledged, but no creation of completely new species has been recorded as yet. The simplest explanation I have for this is that we're not looking in the right places. We keep looking for a large organism that we can identify without a microscope that we can be sure is a sexual exclusive organism, instead we should be taking up our microscopes and observing the growth and change of things we cannot normally see. Why? Because we don't have a recorded history long enough to properly document an origination of a new species. Even if you argue we do when you look at cave paintings and the like there is no scientific evidence that can be drawn from them to properly identify the creatures they portray, which means that 'evidence' would be thrown out of any evolutionary argument they could pose.
"You argued that it could have never supported a population large enough to create the number of fossils necessary to complete the fossil record and provide fossils of missing links." You fail to comprehend what I said. I didn't say a bloody thing about missing links in the record itself. I stated that the planet could not have sustained the number of species that have been proven. If you take account for the species we are lacking then the ability of the world to hold them all becomes inconceivable. Many of the species we have proven as fact are simply too big. If you tried to fit them all into the Earth it would be nearly impossible to move. If one presumes that there has only been one instance of creation, as is the normal theory, then all things existed at once. This is physically impossible, even if you consider them to have had the smallest viable breeding population, which if I remember my textbooks right would be a minimum of 200. Imagine trying to fit at least 200 of every recorded species into the world. Every breed of bird, reptile, mammal, insect, fish ect... Now imagine trying to give them enough space to actually survive. There's not enough habitat available for this to have ever occurred. Now I ascribe to the thought that if creationism is true, then it may well have happened multiple times; however, most creation arguments say it all happened together. Whichever way the world could not have sustained all the creatures that we have evidence of. To even bring the missing pieces into play would make the puzzle sprawl out so far that it falls apart because there is not way that it could be supported, there is simply too many pieces. So then if the planet could not hold all of the species we can account for how do we have them all? Well there's been cycles. Some things die off and others arise to take over their niches, life styles and purpose. This is how our planet has been able to contain all of these things, because there have been cycles of existence.
The fossil record over and over again people repeat that it's incomplete. Your point? Do you expect it to be? When we've only been studying it for a few hundred years and fossils are so rare, as well as often being found in pieces. You might need to find many sites to compose a complete creature, and beyond that, fossils only provide so much, soft tissues are often not preserved. It has only been in the last few years that they have proven that many dinosaurs had feathers. So in a science that is still evolving itself you wish to discard it for not having all the examples you desire? If that is the case you should avoid all physics chemistry and medicine, not to even being on biology. All sciences are continually evolving. We don't even have all the evidence of our own histories. We have yet to discover and prove when Humans started using tools, yet we know for fact we did at some point. Still on the theory that the fossil record his approached with that means that sense there is no proof of when it began there's no proof then of a time when we didn't use tools. That doesn't make much sense now does it? Why? Because to use tools the mind has to first be inspired, and for the use of them to continue someone has to witness and learn of how to use them. Which means that at some point humans must not have used tools, and over time we developed their use as a mental and social evolution of the species.
Animals also learn to use tools and techniques from each other. Primates are an excellent example, but I'll make another. There is a recorded case of a bird that has learned to fish, and does so much like we do. The case has been well documented. A kind of bird has developed a relationship with humans and ducks in the area it lives. According to the report I read of it the bird watched the human feed the ducks. When you feed ducks on the water fish come up to nibble the bread. The bird in question is a kind that eats small fish. After several observations of this feeding of the ducks the bird swooped in and stole some of the bread. It was later witness using the bread as bait to cause fish to come to the surface. This is a learned behavior, one that can be passed down to this bird's descendants by observations and learning. As birds generally care for their young it is even likely that it will be. This bird has thus created a social relationship with humans, as they provide something it needs, bait. Without the ducks though there would be no catalyst for the humans to bring the bait where the bird can get it. Thus this bird and its offspring have thus entered into and created a new symbiotic relationship in which no one gets hurt, except the fish. So as symbiotic relationships are one of the hardest parts of evolution to explain, it becomes relevant. Sense we can witness such a relationship start; we can frame how others started.
Chromosome count is a complicated matter as chromosomes are so easily changeable. Chromosomes link to each other morph trade and shift in all sorts of ways, sometimes making parts unreadable, other times causing new parts to be readable, and sometimes gaining or losing whole sections. Chromosome length can be very different between different ones, there are some lengths of DNA that are two and three times as long as others, and thus have recombined their codes into new forms. All DNA is made of just four types of acid rearranged into new patterns. It is possible to completely rewrite what a gene says to do by misplacing a single set of these acids. In theory you could recode a gene to make an ear when it was supposed to make a nose. On the same token you could make something produce as a liver when it was going to make a spleen. All the possible combinations of genes are possible from a single strand, just mixed up different ways. Some of these ways work, others don't. Still in a single sequence of AT CG you have all the building blocks of all the other genes in the world, just repeat and shift orders as appropriate and you'll eventually make them all, amazing. Not only that but if you question how organisms can gain chromosome count I must out that some organisms, all on the microscopic level, can absorb and process DNA it has salvaged from dead cells, sometimes of other species. These organisms actually extract DNA from cells they encounter and then either keep and assimilate it or discard it. So they can actually evolve and change very drastically, by absorbing the DNA of other organisms. I'm not even going to get into what Viruses do, they're just plain weird. They can't even reproduce their own DNA; they have to use other organisms to do it for them. I'm not even sure I can count Viruses as organisms, they defy the laws by which I typically classify organisms, still they exist, and they reproduce, even if they use something else's resources to do it.
"From what I understand although we can breed hybrid species it doesn't happen in nature and is the result of human engineering." In diploid only species this is generally true, still we occasionally see Hybrid Vigor where a hybrid actually can reproduce and is even healthier then the two original species it comes from. This vigor sometimes does not hold up to progressive generations, but it has the potential if we were to find the right hybrid. Now for plants you seem to forget about certain kinds of reproduction. Some plants and other organisms have the ability to reproduce Asexually, meaning one parent. The plants I was referencing, which I see now I should have gone into more details on, are an example I learned long ago of a type of Fern that cycles haploid and diploid stages. One generation has an odd number of genes and is produced from Meiosis directly with seeds that need not be fertilized; the next recombines the genes of the haploid and actually goes thru normal reproductive cycle for a generation. This means that the diploid essentially clones itself by asexual reproduction, and then the haploid will produce diploid viable seeds, which have recombined DNA. This may be confusing, I'll attempt to explain. The Haploid plant has sexual recombination when its male pollen meets a female plant and makes the new Diploid plant seeds, which will then produce the next generation of Haploid seeds by asexual reproduction. These new haploids seeds get to go thru the meiotic internal recombination of gene trade, crossing, ect... So this plant goes thru two types of recombination in different generations. This plant to me says the nature of our world is to seek gene recombination and distribution. The haploid plant can spread farther as it uses pollen, the diploid just produces a small seed that does not have as much travel potential, which is one of the explanations of this very overall weird manner of existence.
Now someone's saying, but a reproductive cell has to be fertilized, which is normally true, yet not always. There are actually several sexually strange examples in nature of things that are self fertilizing and that don’t require fertilization at all. This is part of the base of asexual reproduction, as well as a component of certain kinds of species production. Take for one example Aphids. They are tiny plant eating insects. Now most people don't make much of them unless they're eating their rose bushes, but Aphids are somewhat unique in their reproduction. Over 90% of Aphids are female, and are actually born pregnant. An Aphid is bone already carrying viable eggs. Only every so often is a male Aphid born and allowed to change the gene pool of a few females who contain both fertilized and unfertilized eggs. Meaning that a single Aphid could produce an entire colony on her own. Generation after generation coming from one individual. There's a species of fish which can actually change sex partway thru their lifecycle. That's right a normal living creature that just swaps sexes as a response to some environmental stimuli. This fish has a population made almost entirely of females, every while or so one of these females, who may even have laid eggs before, will go thru hormone and behavior changes that cause it to become a male, and then to breed with it's sisters. If these two examples don't show that sexual reproduction can go outside the norm in very weird ways, well nothing will.
I’ll rein myself in here and return to the fossil record for a moment. The fossil record is always considered in a frame of reference; normally this is the frame of the theory of Gradual Equilibrium, which means small changes over time culminating in an overall new organism. By contracts you could frame the record in the view of Punctuated Equilibrium, by which organisms change very rapidly, sometimes in only a few generations, or if you want to take truly extreme case one generation. Now to have singular generations punctuation you need to have a catalyst to genetic change in the form of something like high exposure to x-rays, cosmic rays, radiation, or certain chemicals. Cases of such things are very rare and can cause and entire generation of something to be measurably different from its parents. Now a case of this difference being enough to create sexual incompatibility has not been recorded in the lab, but cannot be ruled out of possibility in nature. Similar process fuels multiple generation punctuation, only these sudden jumps are considered to be responses to bottlenecking or the founding effect.
Founding effect is when a population is cut off from its parent group, often caused by geographic changes. Bottlenecking is when a group is decimated, its number reduced by a great degree. We have witnessed founding in many island populations. In many cases of island founding a group that obviously comes from a mainland area will undergo very fast change because they have entered a new environment with new niches to fill and sometimes with few predators to prevent their reproduction. Few natural predators means that the only thing stopping an island founding population is food and whatever reproductive physical structures they may need such as nests. This means in a very short period of time those animals best at attaining food and thus mates reproduce, while those that fail to do so are eliminated from the narrow gene pool. This is how Darwin's famous finches came to be. Those that got food because of their slight differences in trait expression reproduced, those that couldn't died.
Now for Graduated Evolution you have much less dramatic changes over a longer period of time, a prime example would be of how the various shaggy and heavy furred animals of the past ice age have changed into their newer less hairy forms, such as the elephant, the rhino, and even the deer. We have enough evidence of the most recent ice age to fairly easily draw lines of decent for many creatures. The great cats for the most part trace to the Smilodon, the Wolves have a large boned ancestral canine, and Bears also have very closely related even heavier built relations. These beast stand as testimony to change, now I have talked with some people who actually consider the creatures of today as no different from their past incarnations, and whom claim that with the right catalyst could revert back into these greater beasts. I can't argue with that too well as the creatures of today do have the potential and very likely do still carry all the gene necessary to become as their ancestors were, they merely don't express the traits that are not suited to their current lifestyles. This goes into de and re evolutionist theory, which is not under discussion atm.
I explained these two types of evolution because of the gaps in the record that keep being harped upon. If you look at gradual evolution there is argument to be made that we should be finding the in-betweens, but if you look at punctuated evolution then there shouldn't have been enough time over which the change occurred for there to be enough definable fossils to prove the change happened. Which beings as the fossil record is often punctuated itself by vast geological and environment changes means that the evidence for the actively changing creatures may be too small to account for. I thing both types of evolution occur for different reasons, and full believe that one day we may be able to fill some of the gaps. To fill them all though is merely a dream as the likelihood of having them all found is slim to none because not every creature fossilizes, so the record will never be complete without venturing into the field of Cryptozology, which would just undermine the point anyway. Still I claim we have plenty of evidence for in-between creatures today, without need of the record. Look to the seas and witness Flying Fish, and Mudskippers. Turn to the trees and watch the Gliding creatures, mammals, reptiles, and even some kinds of bird merely glide, but you can easily imagine how this could give rise to more then just gliding. I need not present a corpse to prove that some things can cross the normal boundaries of their environment, and that is great evidence of the potential of these creatures to produce new species.
Off and on I've mentioned Catalyst, something that causes reactions to occur or to speed up such, which I need to explain. An organism who has properly adapted often does not need to change, and if they do they don't need to do it very quickly as they have found their Niche in life already. This means for evolution to hold any water at all a catalyst for change must be put into the equation. This means there must be reason to change, and often to do so quickly. If you wish to look for reasons to change in the history of the world you need only look at the many layers of rock that exist and the reasons for why they are layers. Many drastic changes have happened on this planet over thousands of years. Several of these changes took place over the entire planet. There is evidence for many MEEs in geologic records. MEE means Mass Extinction Event. An event in which the environment of the world is changed so drastically that has large portion of the world's species dies. This leaves an unfathomable number of niches open for new species to enter into, and the ones who are to survive the effect itself must adapt with incredible speed. To adapt to such an event one must be very flexible, less specialized and more generalized. You can't be picky about what you eat when half or more of your food sources are now gone. Most creatures that survive such events are small and generalist in nature. This has been seen over and over again in the fossil record, despite its gaps. It sometimes requires drastic measures to survive a MEE. Some species have been recorded to go so far as beginning to reproduce themselves in a larval stage. This happens fairly often in crustaceans. Shrimp larva and the like tend to make up much of the plankton that fills the surface waters of the oceans. Some of these species have been seen when stressed to start becoming sexually mature before they have completed this stage of their life cycle. This means you start having babies that are producing babies. This alone could easily lead to new species; these reproductive larvas no longer need to fulfill their life cycle to reproduce a new generation. If I need to explain how a new species comes from that then you didn't listen when I explained that a new species needs only to be sexually exclusive from its original to be considered unique. If a species needs not change to the next stage of life to reproduce then there are situations where the hormones needed to become an adult are never released, and so you have a species that stays larval forever, because as far as it's concerned when it can reproduce it's lifecycle for evolution is complete, thus the larva is now as much an adult as the original species it came from.
There is little greater evidence for evolution then the sheer number of ways species can reproduce. Put simply once you've had kids evolution stops carrying about you. The spider that is eaten by his mate after copulation is just a productive and effect in evolution as the fish that fertilizes hundreds of eggs every year. To their respective species they have done their part in passing on their genetics. Now creatures that reproduce more often will show a greater impact on the overall gene pool, but the case remains that both have still passed on their genes. That means that as far as evolution is concerned you need only consider a creature while it is productive to its species. This begs the question of why some species only have a few individuals that reproduce, such as in Ant colonies. Well if you are interested in their aspect of nature I suggest you look up Super Organisms, organisms which are formed by many individuals who work together for the success of their species’ gene pool by assisting one another but not necessarily reproducing themselves. The more I study Super Organisms the more I question if Humans could be considered one of them. If one questions this concept I must ask you something. Could you honestly survive as you are today and this minute if you could never again get anything from another human being? Most of us can't, our lives are too interwoven for that, and so we show many traits of a Super Organism. Interesting concept, I promote the exploration of the idea if you have interest in our future as a species.
I'll close this meandering wealth of thoughts with something that most opponents to evolution overlook. If you are to question evolution you must also question the formation of our planet and how it changes. I suggest calling up a geologist and having them explain the movement of the planet's surface, and then a climatologist and have them explain how weather patterns affect the environment and the creatures in it. Evolution can not be taken as a single thing in and of itself; it's interwoven with many other sciences that support its theories. Division of species over the planet alone aids in it's support, because if we were all created then why do we only see certain creatures in certain places, even though there exist almost identical habitats for them elsewhere? Why are all the marsupials gathered in one place? Why do Penguins gravitate south to the most inhospitable place on Earth when they could go north and be almost as secure in their breeding grounds? Then again why do we see so many variations on the same design? Why could a Tiger not survive in South America, further sense they have the potential to, why are they not there? If you wish to claim all things came into play by creationist theory then why in the world do we have so many creatures that seem to be repeats of other creatures? All excellent questions, wish I knew the answer. It could be because the Grand Creator is just artistic, but that seems kind of like a cop out to me. Even then why do some of the creatures of this world seem to exist to be contradictions of the natural order of things, further why does it appear as if there is an arms race between predator and prey? Could not the creator have simply made the prey reproduce fast enough to support the predator without the struggle to survive that we see? Don't know, don't really care either. The facts are as they are, and it is not my field to question whatever put them here, but to study them and try to make them all work in a way that makes sense. Why must I seek sense in the madness, well because I'm human. That's what we do, and I personally take great joy in it.