upward evolution?

Question

What is the scientific rationale for assuming that evolution is always on an upward curve? I assume that it is assumed because I've never heard anyone speak of it going backwards.

If indeed it is always improving the organisms of life, what would be the motivation for it to go in that direction?
Please don't say God.
There must be some scientific reason that evolution "selects" in favor of the improved model. If that be the instinct for survival, then I must ask how did instinct evolve especially when talking about simple cells.

Your telling me "no direction" yet we started as simple cells and now we are humans and that is not upward?

"advantage"

This notion that an organism (animal) that has "aquired" an advantageous trait will reproduce more. Is that really a scientific statement?

Your starting to annoy me.
Aquired by birth, okay?
How does that statistcally make it reproduce more. Does it think to itself "hmm this is a good trait, I think I'll pass it on". You just assume it.
Statistically all your bs is a real bad bet. You need billions of years to allow your system of aquired traits (mutations?) to move life sideways along the evolutionary ladder till we get to humans. Not upward, not a higher form, just better to survive by instinct.
Keep preaching your religion. Never mind that it flies in the face of common sense.

Answer 1

Why is it that the ignorant are so much more certain in their beliefs, no matter how wrong they are? [Your belligerent tone invokes a hostile response.]

The first thing you need to learn in order to understand any subject is the vocabulary and it is clear that you do not have an understanding of the language of biology. Evolution is defined as a change in allele (different versions of a gene) frequency in a population over time. Individuals do not evolve, only populations. For example, if you were to sample a population of an island and sequence the DNA that codes for a particular enzyme (say an enzyme involved in blood type) you could determine that X% are blood type M and Y% are blood type N and Z% are type Q. If a boatload of people arrive from across the globe, there would be a change in the gene frequencies in the new, expanded population. That is evolution. Other ways evolution can happen are, mutation, recombination, sexual reproduction, gene flow (emigration, immigration).

The reason you should not have heard of anyone speaking of evolution going backwards (at least not from the informed) is because evolution is not directed which means that there is no scientific rational for saying evolution is on an upward curve (whatever that means). The frequency of alleles changes, there is no up or down.

What most people have difficulty with is the mechanism behind evolution. Why does the allele frequency change in a population over time? The answer that is accepted by the overwhelming majority of scientists is Natural Selection. However, most people believe in magic (aka god). Evolution (change) does not select. Evolution (change) is the result of selection.

Natural Selection can be summarized as follows:
1. There is variation in traits in a population that are heritable. [If the trait is not heritable, then it doesn't matter for evolution. If the radioactive spider made Spiderman sterile, then evolution doesn't care if he's a superhero. He would be a reproductive failure.]

2. There is competition in a population for limited resources. [Should be clear enough.]

3. Individuals with traits that give an advantage in gathering resources and surviving the CURRENT environment will have an increased PROBABILITY of reproductive success. [Selection happens in the moment and nothing is sure in life. Selection can not predict the future. It does not say, this trait is a big handicap now but it will be advantageous generations from now so I'll keep it around. And, even if you have a superhero powers, it doesn't make you immune to flukes of fate and chance.]

If we are talking of simple cells (bacteria for instance) there is no instinct. Instinct in biology is a complex trait that is found in organisms with complex nervous systems. Bacterial (like all life) are a collection of macromolecules that are there to make more copies of itself. There you have the purpose of life, including humans. Our bodies are nothing more than biochemical machines that are made so that a particular set of DNA can make copies of itself.

Keeping to the simple cell example, we can observe evolution happen in mere hours by treating bacteria with antibiotics. Different antibiotics work in different ways. One mode is to bind to bacterial ribosomes to prevent protein production. Bacteria have different ribosomes than eukaryotes which is why we can take the drugs and not suffer the same consequence. There are more bacteria in our gut than there are cells in our body. About 10% of our mass is bacteria. The point being is that there are a lot of bacteria in our gut. When you take an antibiotic, the drug will be able to kill most of the bacteria. However, there are many different kinds of bugs. There will be some that have a slightly different set of DNA that makes a protein that is slightly different. Also, while DNA replication is done with great accuracy, there is still a very low error rate (about 1 base change per 100,000,000 copied) but, if you have a population of trillions that reproduces every 20 minutes, that means thousands of mutations every hour. Some of these mutants will have a change in the DNA for a ribosomal protein so that the drug does not bind as well to the mutant ribosome. The mutant germ will be able to continue to make proteins and survive while the "normal" bugs get killed off.

You would see a huge change (evolution) in the frequency of the ribosomal genes in the gut population before and after antibiotics. The susceptible germs die so their gene frequency goes down, while the mutant germs survive and make more copies and frequency goes up. You can experience this during the course of drug treatment. Initially, there are side effects, like diarrhea, that goes away after a few days. The bacteria you need also die but they too are subject to the same selective pressure that enhances the survival of drug resistant organisms.

There is no instinct for survival here. The germs do not say, "oh no! There's a drug that's inhibiting my ribosomes so I'd better change my DNA for ribosomal proteins." The variations occur randomly and it is only those with advantageous mutations that benefit. When you throw a thousand darts, one is going to hit the bullseye but most will not.

So then, why is the population of drug resistant bacteria low to begin with? Why isn't the world full of super bugs that are indestructible? Selection depends on the environmental conditions. Traits that are advantageous one moment, can become liabilities under different conditions. In the absence of drug selection, the resistant bugs are at a disadvantage. They are making mutant ribosomal proteins that are not as efficient as normal ribosomes, or they are making expensive transporters to pump out drugs that are not there.

Going over the development of complexity and multicellularity is a completely different issue. Biology, like learning any subject, requires years of education and training, much more than can fit into this message.

p.s. "your" is a possessive while "you're" is the contraction for "you are."


*****Addendum for Questioner:

Your comment is beyond the scope of the initial question that was asked so I’ll keep this short. Interesting how creationist will selectively use the words of the odd scientist here and there when it suits them but ignore the voices of the vast multitude of scientists that accept a model contrary to the one that the faithful hold on to without any evidence except for that it feels good to them.

Dr Spetner is a physicist (can’t find a credible biologist to use?) who is well outside his area of expertise, which is clear if he really did say, “all point mutations…reduce genetic information.” He left APL at Johns Hopkins in 1970. It is safe to say that quite a lot has happened in biology since then. Why not go back to the 19th century, because the changes in biology have been so great in just a few decades.

What is lost in a point mutation? On nucleotide is replace by another. That is still information. Does he mean loss of function? But there are numerous cases where a single nucleotide change gives rise to new or modified function.

A single amino acid change increases the esterase activity of Lc(alpha)E7 making insects resistant to pesticides.

A single amino acid change converts a violet photopigment (SWS1 opsin) into an ultraviolet photopigment in insects letting them see in the ultraviolet range.

A single amino acid change in a sodium channel makes flies resistant to DTT.

A single amino acid in cry2 alters flowering time in plants.

A single amino acid change in Hemoglobin b gives frogs enhanced oxygen transport at high altitude.

In each case, a single mutation is sufficient to give the organism an adaptive trait.

Again, the problem here is a lack of understanding. Know what it is you are criticizing because it looks foolish to bring up points that have no standing.

Answer 2

A Good Question, Let's Take the Example of Antibiotic Resistance In Bacteria, as Long as the Antibiotic is Present, the Bacteria Having the Resistance, is At a Selective Advantage, if the Antibiotic is Not Present, No Advantage, Probably a Disadvantage.


I See "Upward" and "Downward" as a Human Notion.


emucompboy, I Heard, Long Ago, "Populations Evolve, Individuals Do Not".


Nimrod, the "Founder Effect"?

Answer 3

Nobody has postulated that there exists a "curve" for evolution. Nor does evolution go "up" or "down". You are speaking about something that doesn't exist.

Evolution is simply species changing because certain traits are better for survival (and therefore breeding) than others. When the environment causes animals with trait X to die, you stop seeing trait X in the population after a while.

When an animal is randomly born with trait Y, and trait Y is very advantageous for survival, the animal will tend to be successful and produce many young. Therefore, you will see more animals with trait Y after many generations.

This can be applied to brain functions like instinct, as well as physical traits like leg length.

Answer 4

> assuming that evolution is always on an upward curve
Nope. Evolution doesn't move "upward." All you get is a favoring of the allele sets of those who have children.

> what would be the motivation for it to go in that direction?
Fitness for a particular environment plays a role in the ability of an individual within a population to reproduce successfully. If an individual's allele set within a particular environment confers a reproductive advantage, then these alleles will (more likely) increase in frequency within the population. This is "selection" at work.

Answer 5

It is a common misconception because most have only a limited understanding of the subject. It always makes something more evolved for a particular niche. If it is a crayfish in a cave, then it is better to not have to grow eyes. That is evolving backwards in some sense.

You cannot have much instinct as a cell. Perhaps movement towards or away from some stimuli can be programmed but not much more. The most fit animal passes on its characteristics. We are the result of 4 billion years of subtle improvements.

Answer 6

Evolution like scientific research and technological innovation has a number of advantages but not totally detached from some disadvantages.
Quadruped`s normal blood glucose is around 20mg/dl.
Lower apes 50mg/dl.
Higher apes 70mg/dl
Humans >70 upto 80mg/dl.
Human diabetics - much more
Diabetes is an evolutionary disease.
The backward evolution is generally referred to "involution"
Bronchial Asthma is a good example
During an episode of asthma humans are comparable to amphibians just migrating to earth. Their respiratoory tract is filled with saline secretions and they derive maximum comfort in amphibian posture. Respiratory muscles are functionally not yet evolved in spite of full development of human body
Diabetes and Asthma do not occur in the same individual.

Answer 7

>"Your telling me "no direction" yet we started as simple cells and now we are humans and that is not upward?"

YES!!! That is a very subtle and important point to understanding evolution and biology.

Humans have a tendency to see things that evolve in the "human" direction to be "upward" ... but this is not a *scientific* concept. There is no UP in biology.

Really, the same thinking that leads you to think of single-celled to multi-celled transition as "upward", is the same thinking that leads to viewing the transition from "ape" to "human" as "upward." The sooner you drop that thinking, that's when you start to talk like a biologist.

Also, don't forget that life on this earth is *overwhelmingly* still single-celled. We multi-cellular organisms (all plants, all animals, all fungi *combined*) are a sliver compared to the number of single-celled organisms on the planet. Also, we are newcomers! We multi-cellular critters have only been here about a billion years ... the single-celled critters had the planet all to themselves for almost 3 billion years!

As for the "direction" of evolution ... that is also somewhat an illusion. The only tendency that is certain is that things will evolve in whatever direction makes them more fit for a certain environment. For example, vertebrates went from water-dwellers to land-dwellers, but then some mammals returned to the water (whales and dolphins).

Yes there are some exceptions (like multi-cellular organisms don't (as far as we know) evolve into single-celled organisms), but, again, that's because there apparently is no evolutionary advantage.

To answer your original question:

>"There must be some scientific reason that evolution "selects" in favor of the improved model."

Yes. That's natural selection. It's just a statistical thing. Anything that gives some individuals an advantage in survival or reproduction, just gets reproduced more.

In other words, it's built right into the fact that organisms reproduce with inheritance.

>"If that be the instinct for survival, then I must ask how did instinct evolve"

Again, Natural selection. Things with that instinct live longer .. and therefore produce more offspring ... all that is needed is for aspects of that instinct to be inheritable.

> ... "especially when talking about simple cells."

Single-celled organisms don't have what you and I might call "instincts" ... but they eat and reproduce and avoid toxins ... not quite an "instinct for survival", but the net effect is the same.

{edit}

> "This notion that an organism (animal) that has "aquired" an advantageous trait will reproduce more. Is that really a scientific statement?"

Neither I nor anybody on this page has used the word "aquired." Natural selection says that an organism (animal) that *IS BORN WITH* an advantageous trait will *TEND* (on average) to reproduce more. Again, this is a *statistical* principle. Not every single individual born with that trait will reproduce more (it could get eaten by a tiger as an infant) ... but *on average* those with the advantageous traits will reproduce more.

{edit again} ... ... { with apologies for the length of this answer ... but you have digressed from your original question about the "upward" nature of evolution}

>"How does that statistcally make it reproduce more. Does it think to itself "hmm this is a good trait, I think I'll pass it on".

No. An individual does not pick-and-choose which of its traits to pass on. Again, natural selection is a *STATISTICAL* principle ... but you insist on restating it in terms of individual animals, and now about their individual choices to pass on individual traits. You are restating natural selection in an absurd way just so you can call it absurd.

You are arguing like you have an inability to understand a *STATISTICAL* concept. Over a population of thousands, not all will reproduce the same number of offspring. What makes the difference? Advantageous traits. It's NOT choices that individuals make to reproduce more or pick certain traits to pass on. It's NOT instinct (my point above is that survival instinct is a *product* of natural selection, not the *cause* of it).

Those individuals with advantageous traits will *TEND*, *ON AVERAGE* to survive better and therefore leave more offspring that have those very traits.

I'm amazed that you would not only dispute that statement, but call it "bs", "religion", and say that it "flies in the face of common sense."

Answer 8

Evolution, as it has proved itself to be, it's a mechanism for survival. So Life as we know it, won't work itself to it's termination but towards it in a changing environment, still, if the organism doesn't have the necesary potential to adapt, it'll become extint.
You are looking at instinct as a result of reasoning or an assumed motivation, be it simple cells or people, chemistry is the answer. You know your food or die.

Answer 9

I have some other problems with the theory. What they always give as scientific evidence is natural selection, but that is not molecules-to-man evolution. As Hugo de Vries has said, “Natural selection may explain the survival of the fittest, but it cannot explain the arrival of the fittest.”

Natural selection is a logical process that anyone can observe (and it was actually a creationist named Edward Blyth who wrote about it in 1835—7, before Darwin). We can look at the great variation in an animal kind and see the results of natural selection. For instance, wolves, coyotes, and dingoes have developed over time as a result of natural selection operating on the information in the genes of the dog kind.

But natural selection can only operate on the information already contained in the genes; it doesn’t produce new information. There are limits. For instance, you can’t breed a dog to the size of an elephant, much less turn it into an elephant.

The different dogs we see today have resulted from a rearrangement or loss of information from the original dog kind; no new information was produced. What are they? Dogs. What were they? Dogs. What will they be? Dogs. There is a big difference between subspeciation (variation within a kind) and transspeciation (change from one kind to another).

To go from that first single celled organism to a human means finding a way to generate enormous amounts of new information. You need the recipes to build eyes, nerves, skin, bones, muscles, blood, etc. Without a way to increase information, natural selection will not work as a mechanism for evolution. Evolutionists agree with this and so they point to mutations (copying errors in the genetic code) to provide the new information for natural selection to act upon. So, the question is, can mutations produce new creative information?

Dr. Lee Spetner (a highly qualified scientist who taught at John Hopkins University) said, “All point mutations that have been studied on the molecular level turn out to reduce the genetic information and not to increase it.”

He also said, “The neo-Darwinians would like us to believe that large evolutionary changes can result from a series of small events if there are enough of them. But if these events all lose information they can’t be the steps in the kind of evolution the NDT is supposed to explain, no matter how many mutations there are. Whoever thinks macroevolution can be made by mutations that lose information is like the merchant who lost a little money on every sale but thought he could make it up in volume.”

Dr. Warner Gitt (Professor at the German Federal Institute of Physics and Technology), in answering the question (Can new information originate through mutations?) said, “...this idea is central in representations of evolution, but mutations can only cause changes in existing information. There can be no increase in information, and in general the results are injurious. New blueprints for new functions or new organs cannot arise; mutations cannot be the source of new (creative) information.”

Even the somewhat beneficial mutations they point to like antibiotic resistance in bacteria are always a rearrangement or loss of information, never a gain. For instance, a mutation that causes the pumps in its cell wall not to work in a certain way so it doesn’t suck in the antibiotics we try to kill it with. You see, it is resistant because of a loss of an ability.

This kind of stuff is used as evidence for evolution, but in every mutation (even the beneficial ones), this is always the case. Evolution requires new creative information, not a loss of information. Everything we observe is going in the wrong direction. Mutation, which evolutionists frequently hide behind, is not a magic wand that transforms living organisms into more advanced forms.

Answer 10

Evolution DOESN'T have direction. No-one in science says this. Evolution works by Natural Selection - what aids in survival, well survives and is passed on. It is simple statistics.

edit - Natural Selection leading to changes in the inhertiable traits within the population from generation to generation is abundantly observed.