Inter-connectedness Of All Life

not really an overstatement. For every species, evolution is the accumulation of random mutations. Once a subset of a population accumulates enough mutations it is no longer part of that species. Both species remain but only time will tell whether one or the other or both or neither will survive. Both populations will continue to accumulate random mutations moving forward in time.

When I say irreversible, I mean that the accumulation of the mutations can’t be reversed. Evolution goes only in one direction - forward. Always building on previously accumulated mutations.

It sounds too melodramatic. In the common vernacular, genetic variations happen in all directions randomly.

George

No evolution does not go in all directions randomly. It can only go in the direction of the already accumulated mutations. And it can’t go backwards.

Of course it can … if conditions change.

You can gain genes… you can lose genes. You can even lose the gene you just gained … but I wouldn’t put a bet on that happening. But it could still happen.

There are no rules in randomness.

(Remember, the case of the Peppered Moth is not a case of speciation… but it’s a case of genetic variation within a gene pool. Individuals do not evolve … GENE POOLS evolve).

The peppered moth evolution is an example of evolution moving forward and being irreversible. A subset of the population had random mutations that made them blend in more with the sooth. The lighter one get eaten, only the ones with the mutation have better survival. But the random mutations go forward and more mutations accumulate and the sum total produces some never expected nor intended.

LoL…

@Patrick, the Pepper Moth gene pool has variants in its population throughout its history. First one variation is dominant… then the environment changes again and different variant becomes dominant.

There are no rules saying the old variant can’t return to dominance.

Reptiles have legs… some reptiles lose their legs and become snakes. There just aren’t any rules.

George

@gbrooks9

George,

There are too rules. Change must benefit or do no harm to the population ecologically.

Variation is random, but selection is not.

Stickle back fish developed the stickle as a protection, but later where the stickle became a liability they lost it.

not true. all snakes still have leg bones - very tiny unused ones. And four legs to boot.

http://phenomena.nationalgeographic.com/2015/07/23/a-fossil-snake-with-four-legs/

I’m not talking about selection. I’m talking about variation.

If they gained the stickle and then lose it … sounds like change is NOT one way. There really is no way in the directions of variation - - except if God is guiding it. That’s what Theistic Evolution is all about.

@Patrick, if that is true, I would just pick a different example.

In the article below, it comments that one species of snake (now extinct) still had small hind legs,
but no front legs at all!

" “Synchrotrons are enormous machines and allow us to see microscopic details in fossils invisible to any other techniques without damage to these invaluable specimens,” said co-author Paul Tafforeau from the European Synchrotron Radiation Facility. The new 3-D model determined that Eupodophis, in its lifetime, had two small regressed hind limbs and no front limbs."

I don’t really understand why it is so important to you that evolution can never be reversed?

http://news.discovery.com/animals/zoo-animals/snakes-lost-legs-evolution-110207.htm

@TiomothyHicks
This explanation suits me: The greatly enlarged primate brian (~1,400 cc in Neanderthal) was an exaptation–it helped them survive by their wits but was greater than need be. Only after Homo sapiens had been around for 150,000 years did some (as yet unknown) **epi-**genetic change take place which ‘programmed’ one (or a few) Homo sapien brains to behave as Minds which suddenly produced language, art, music, and a sense of reverence for their dead (& a desire to communicate with their Maker?) Through language this program could be transferred epigenetically to others of the species, thus spreading culture and morality much more rapidly than Darwinian evolution–more like Lamarkian.

I expect that many (most) responders will object strongly to this scenario, but it suits me OK
Al Leo

1 Like

I believe you need genetic changes for language.

Tim, evolution doesn’t happen to individuals. That’s why you’re having trouble with comprehension.

No, that is false.

Patrick, you’re feeding into this false idea that there’s no preexisting reservoir of polymorphism on which selection acts. Please think more carefully about this.

@aleo

I don’t have much of a problem with that explanation… Genesis 2:7 says that Man BECAME a living soul. I don’t know all the ins and outs, but to me, that halfway implies that man was something else before “God breathed into his nostrils.” Maybe I’m making too big of a deal about subtlety in the text, but rather than saying “became” the author could have said “made” … Which seems to open up the idea of a “man” that existed before “man” (as we know it today) came to be — the Jewish teach that this Man was blessed with the neshama (the soul in other words). There’s a 12th century book that goes into this a little more in depth, by Moses Maimonides, that I find interesting.

The main thing I’m confused about is your doctrine of Original Blessing (what most people explain as Original Sin). Can you elaborate a little more by what you mean here? Are you saying that the Serpent didn’t beguile Eve? I’ve never heard of “original blessing” until I saw you talking about it, so I’m not sure what it’s all about.

@Patrick @gbrooks9

There seems to be a lot of confusion on what Evolution can and can’t do. Patrick you stated that the last common ancestor of a human and a banana was a bacteria — correct me if I’m wrong, but doesn’t that mean that Evolution split off into two separate directions? One group became the Animal Kingdom and the other the Vegetable Kingdom?

I’m not sure what’s to stop Evolution from taking a different direction — some fish grew legs becoming land animals. Other land animals lost their legs and became dolphins and whales.

@Joao

Evolution affects populations. I’m a little confused here … Aren’t populations just groups of individuals, anyway?

When do mutations / adaptations begin? At birth or during the organisms life? Or is there simply not much distinction?

Newbie here…

-Tim

[quote=“TimothyHicks, post:37, topic:3245”]
I’m a little confused here … Aren’t populations just groups of individuals, anyway?[/quote]
Yes, they are. But individuals do not evolve. Stating evolution as one individual “evolving into another” is a rhetorical staple of denialists.

I don’t see any reason to put those terms together with a slash. Mutations occur with every cell division, but their number is dwarfed by the existing reservoir of genetic variation. Adaptations occur to populations. You’ll never understand evolution without grasping this essential concept.

[quote=“TimothyHicks, post:37, topic:3245”]
Patrick you stated that the last common ancestor of a human and a banana was a bacteria — [/quote]
That was wrong. Bacteria are just as evolved as we are. That being said, we do have a common ancestor with bananas, it just wasn’t a bacterium.

Evolution is primarily about populations splitting. It’s not a ladder or a line.

[quote]One group became the Animal Kingdom and the other the Vegetable Kingdom?
[/quote]More like four kingdoms at present count.

Keep in mind I was never taught evolutionary theory in school. And when it was explained to me it was explained by people who didn’t believe it … Naturally my view of it is distorted.

You wrote “is the rhetorical staple of the denialist.” I’m not sure if you’re calling me a denialist or simply the particular statement I made a common remark of denialism.

I can’t argue against something I don’t really understand … So that’s what I’m doing. Trying to understand it.

Hundreds of thousands of mutations occur through out an organisms lifetime. These mutations can be good, bad, or neutral. Natural selection weeds out the specimens that were least likely to survive.

Hopefully my reasoning is on point so far.

The organisms that got the good mutations (or even neutral ones) are the ones most likely to procreate and pass on their genes to their offspring. Their offspring then inherits those traits (a mix of the dad and the mom genes).

Is this — in a very simplified fashion — how evolution progresses? Not in it’s entirety, but just partly?

Moving on to my next questions — how does speciation work, and have we witnessed it happen?

(Remember I’m not against evolution. I’m just trying to learn how it works)

Does this happen by separation of environment? When a division occurs between a breeding population, thereby, leaving those two different groups to mutate on their own? And over many, many generations, those two groups might no longer be able to procreate with each other anymore?

Sorry if I’m bombarding you with questions … I’m just trying to fit the concepts inside my head that makes sense.

I don’t wanna sound like I’m resurrecting old and outdated arguments — but you wrote that the bacteria is just as evolved as we are. Why did the bacteria remain basically unchanged while our history (evolutionary history) went through such a complicated and drastic journey?

-Tim

[quote=“TimothyHicks, post:39, topic:3245”]
Keep in mind I was never taught evolutionary theory in school. And when it was explained to me it was explained by people who didn’t believe it … Naturally my view of it is distorted.[/quote]
I understand.

I am not calling you a denialist. Denialists take advantage of your lack of understanding to emphasize mutation. Simple question: did Darwin know about mutations?

I agree and I’m trying to help.
Simple questions:

  1. Are organisms in a population different from each other?
  2. Are at least some of those differences heritable?
  3. Does every organism leave the same number of offspring?

Think about these in the context of humans.

Only those that occur in the germline are relevant to evolution, and they add very little to the variation already present (see #1 above).

My point is this: understanding evolution doesn’t start with mutations!!! Understanding evolution starts with observing heritable variation in a population.

You’re missing the simple obvious existence of heritable variation and focusing too much on mutations. New mutations contribute very, very little to the reservoir of variation already there.

If you think of them as variations, then you’re on track. Thinking of them as new mutations is the problem.

Two things: “traits” is far superior conceptually to “mutations,” but Mendel showed that much of inheritance is particulate, not “a mix.” Do you understand dominant vs. recessive alleles?

The concept that you are missing is that genetic variation is sufficient–new mutations are not required.

There are multiple mechanisms, and yes.

Absolutely zero new mutations are needed for this type of speciation (allopatric)! With a barrier, existing genetic variation in each of the now-separate populations is sufficient to allow drift, even in the absence of any difference on either side of the barrier, to lead to reproductive isolation and speciation.

Correct, even if we could shut off all new mutations.

What makes you think that our common ancestor with bacteria remained basically unchanged? How many different species of bacteria are there?

Individuals do not evolve… GENE POOLS evolve.

If a gene pool is divided into two breeding populations, over time, breeding compatibility can be lost between the average individual of the two different gene pools.