Evolution Lesson

[HitchSlap]

Thank you.

Here's another one:

Would rabbits in the Precambrian falsify evolution?

Yes, yes, AV. Even cud chewing bunnies.

 

[Speedwell]

Does theistic evolution count as creationism?

No. Only devotion to an interpretation of Genesis as literal and inerrant history counts as creationism.

 

[Cearbhall]

Is there a perfect definition? If not, what is the problem with the ability to perfectly define the criteria?

A perfect definition would basically be a list of exceptions and explanations of those exceptions. The problem is that nature and evolution are without intention, so things don't often fit into perfect categories. We come up with concepts like "species" to aid our understanding of the world and to have a way of talking about it.

 

[HitchSlap]

But that's just begging the question. One programming definition can describe millions of millions of functions and be precise. One astronomical definition can describe millions of millions of planets and still be precise. What is the problem in biology that it can't describe a species with precision? What about extinct "species" which we have no idea whether or not they could produce fertile offspring? What do we call something that does not produce fertile offspring? A species, or, something else? I've just always wondered why biology has so much trouble defining things. Dare I ask the definition of a "genus"?

You think one definition to describe millions of species should be concise and easy?

 

[EastCoastRemnant]

You know the 2LOT has zero to do with ToE, right? Right?!

Based on your ignorant comment/question, I'll assume you've never read or studied the laws of thermodynamics, let alone the second one. So here, save yourself some future embarrassment and take a moment to read this:

Second law of thermodynamics - Wikipedia

Living organisms have a very low entropy. This is because their bodies are very neatly ordered.

The second law of thermodynamics states that the total entropy cannot decrease, only increase. This is why living organisms give off thermal energy: they lower their entropy, but the total entropy increases.

Organisms take in material from the outside environment to use as an energy source for decreasing their entropy. This is how the second law of thermodynamics applies to living organisms.
How do the laws of thermodynamics apply to living organisms? | Socratic

May I also suggest that free radicals are completely in line with the 2nd law on living organisms.

 

[HitchSlap]

May I also suggest that free radicals are completely in line with the 2nd law on living organisms.

No, you may not.

 

[John Hyperspace]

You think one definition to describe millions of species should be concise and easy?

No one else seems to have any problem defining terms, so I should think one definition should be viable to define "species". If it's not the your statement isn't concise and easy to understand since it used a term with a definition that isn't concise and easy. Now your answer becomes a question of, exactly what are you saying when you say "millions of species" since apparently neither of us knows exactly what a "species" defines.

Moreover I'm wondering how the word can possibly describe any past organisms since we have no idea what can produce fertile offspring with what; and without knowing that, how can we claim changes in species when we can't even identify a past "species" in any meaningful way.

Add to this that there are probably(?) more extinct creatures than those living (and of those living not all apparently meet the criteria of a "species"), and so the word "species" is not only ill-defined, not concise and not easy, but doesn't even describe or define the major group of creatures that have existed.

How can we discuss change in species without even knowing what a species actually is? If the offspring are fertile, then? The offspring are the same species? What is the criteria for change in a species? How is it determined?

 

[Bugeyedcreepy]

No one else seems to have any problem defining terms, so I should think one definition should be viable to define "species". If it's not the your statement isn't concise and easy to understand since it used a term with a definition that isn't concise and easy. Now your answer becomes a question of, exactly what are you saying when you say "millions of species" since apparently neither of us knows exactly what a "species" defines.

The problem is that nature doesn't conform to neat categorisations like we want them to. We have a general definition that says a species is a population that interbreeds with itself. The thing is, because speciation is a thing, we have various life forms at every stage of speciation, inconveniently messing up our neat definitions. Lookup ring species for example. We have salamanders and european/black gulls as living examples of these paradoxes. The other problems, we could define something as a species, only to find out that they can interbreed in limited ways (i.e. infertile offsprings, such as Ligers and Mules), or don't interbreed for sexually selective reasons, even though biologically they could produce fertile offspring. Given time, they will inevitably speciate. Would/should they be separate species, or the same species?

Moreover I'm wondering how the word can possibly describe any past organisms since we have no idea what can produce fertile offspring with what; and without knowing that, how can we claim changes in species when we can't even identify a past "species" in any meaningful way.

We have hundreds of thousands, if not millions of fossils of various life forms over a wide periods of time. In many cases, we can see these life forms progress through stages. Take us for example, here's a table that neatly sums up the grey area between species...:

We have so many fossils of hominids throughout the ages, and we sometimes find it hard to distinguish the difference between them at the base of their divergences or axis of change. Their fossils though tell us enough that we know they're different enough to be separate species for the purposes of classification.

Add to this that there are probably(?) more extinct creatures than those living (and of those living not all apparently meet the criteria of a "species"), and so the word "species" is not only ill-defined, not concise and not easy, but doesn't even describe or define the major group of creatures that have existed.

About 98% of all species that have ever lived are extinct by our best estimates.

How can we discuss change in species without even knowing what a species actually is? If the offspring are fertile, then? The offspring are the same species? What is the criteria for change in a species? How is it determined?

Because what we classify as a species is something that isn't a hard line in nature, we have to be somewhat unclear at the edges. Galapagos Island Finches are an example. even though they're classified as separate species, there are a handful that do interbreed from time to time, but this is rare, and not across the board for the 14 or so individually identified species. The rest don't interbreed, could they produce fertile offspring if they did though? They all came from the same population of South American finches though a few million years ago. Evolution: Library: Adaptive Radiation: Darwin's Finches

 

[sfs]

Well, no; I would disagree. What happened that it took astronomers hundreds of years to properly define their terms, and Pluto paid the ultimate price for their incompetence.

Your account doesn't seem to be of actual history here. Why is a definition that excludes Pluto a proper definition, while one that includes it isn't? What does "properly define" even mean? The definition is for convenience only -- it doesn't reflect anything fundamental about one group of bodies. It's also still fuzzy. Is a solitary body with the mass of Jupiter a sub-brown dwarf or a rogue planet? Maybe some official body will decide, but it will again be a matter of what's convenient.

Okay now I'm wondering how we presume that species have changed over time.

We don't. We conclude, based on evidence, that groups of genetically related organisms change over time. "Species" is a label of convenience we apply to distinguish different stages in a nearly continuous process.

Am I understanding correctly in that the word "species" doesn't always mean "species" and especially not when talking about extinct "species": so the word is being used basically without a definition,

It doesn't always mean the same thing, no. Your conclusion -- "basically without a definition" -- does not follow, however, and is not correct.

And do we just throw "genus" away and say "no one knows what a genus is, let alone the rest of King Philips Coming Over From"?

You don't have to throw it away, but you should recognize that it doesn't indicate any real, distinct property. "Species" is at least intended to describe a biological reality; all of the other levels are completely arbitrary.

 

[sfs]

No one else seems to have any problem defining terms, so I should think one definition should be viable to define "species".

If you think that, then you must speak a very strange language. Look in any dictionary, and you'll find multiple definitions for most words. What are the precise boundaries of terms like "red", "big", "pretty", "conservative", "Christian", "hot", "solid" . . .?

 

[Speedwell]

No one else seems to have any problem defining terms, so I should think one definition should be viable to define "species". If it's not the your statement isn't concise and easy to understand since it used a term with a definition that isn't concise and easy. Now your answer becomes a question of, exactly what are you saying when you say "millions of species" since apparently neither of us knows exactly what a "species" defines.

Moreover I'm wondering how the word can possibly describe any past organisms since we have no idea what can produce fertile offspring with what; and without knowing that, how can we claim changes in species when we can't even identify a past "species" in any meaningful way.

Add to this that there are probably(?) more extinct creatures than those living (and of those living not all apparently meet the criteria of a "species"), and so the word "species" is not only ill-defined, not concise and not easy, but doesn't even describe or define the major group of creatures that have existed.

How can we discuss change in species without even knowing what a species actually is? If the offspring are fertile, then? The offspring are the same species? What is the criteria for change in a species? How is it determined?

Are you a Platonist? Do you believe that the category "species" exists anywhere but in man's mind?

 

[Loudmouth]

Is there a perfect definition? If not, what is the problem with the ability to perfectly define the criteria?

The problem is our human expectation that nature fit neatly into human defined categories. There is no reason why life must fit into perfectly described category.

Due to the intrinsic nature of life and fossils, no single definition will ever work. If we define species as a population that interbreeds, then that definition won't work for the majority of species on Earth which are asexual. On top of that, we can't determine which fossils mated with each other. Even when we are dealing with sexual species, you can have significant amounts of cross breeding between species.

Long story short, species are a human construct that we try to project onto biology.

 

[Loudmouth]

What is the problem in biology that it can't describe a species with precision?

Because species are a human construct, not a real thing in biology.

What about extinct "species" which we have no idea whether or not they could produce fertile offspring? What do we call something that does not produce fertile offspring? A species, or, something else? I've just always wondered why biology has so much trouble defining things. Dare I ask the definition of a "genus"?

We have trouble defining species because species evolve.

 

[Loudmouth]

If we came from primates, why are primates still around?

For the same reason that there are still Europeans even though many Americans descended from Europeans.

 

[Loudmouth]

But anyhow, one of my questions is, how on earth did different 'sexes' arise?

The simplest answer is that it went through three phases:

1. Undifferentiated sexes where the gametes are equal in all characteristics.

2. The sex organs differentiated into ovaries and testes, but both organs were carried by each organism, otherwise know as hemaphroditism. There are still many hermaphroditic basal vertebrates, such as the sea squirt. Earthworms are another example.

3. Different sexes appeared as individuals had just ovaries or just testes.

If we all started from single-celled creatures and many creatures like amoeba and spyrogyra just split in two, so to speak, to multiply...well, how did creatures after that start getting male and female organs, not to mention wombs and female breasts or various forms of udders etc, to reproduce and feed their young? I mean, I can't see that there would suddenly be an animal (however 'primitive') suddenly develop a penis and close by, there is one that develops a vagina etc etc etc. So presumably, this would have to develop gradually, but I just don't understand how.

I don't know if you can explain the process in any way?

Many animals don't need a penis, vagina, womb, udder, or other features you are pointing to. Look at fish. They just expel sperm and egg into the water. No mammary glands, wombs, or external sexual organs.

 

[Loudmouth]

Okay now I'm wondering how we presume that species have changed over time.

That is what we observe in the fossil record.

Since we can't seem to tell what a species is among living breeding organisms, how is it being proposed that there has been change in species in the past?

We don't have to force species into specific groups in order to measure the differences between individual fossils in different geologic layers.

Unless you must be going by some other definition of "species" when dealing with extinct groups of organisms? Am I understanding correctly in that the word "species" doesn't always mean "species" and especially not when talking about extinct "species": so the word is being used basically without a definition, but is being used in a variety of ways, each with their own set of criteria which do not actually describe anything with precision? Meaning the word "species" has no real functional definition except in the present, and even in the present the definition isn't precise.

Species has multiple definitions in multiple contexts.

And do we just throw "genus" away and say "no one knows what a genus is, let alone the rest of King Philips Coming Over From"?

If you want to, sure. Linnaean taxonomy is a bit outdated anyway. It is humans who decide which species belong in a genus. There is no biological tag on organisms that says what their genus is.

What is the definition of "evolution" anyway?

It is most often defined as a change in allele frequencies within a population over time. It is also defined as descent with modification.

 

[PsychoSarah]

Assuming creationist know nothing of Evolution, or Biology.

I'm not assuming that, in fact, quite a few do, I just wanted to make a thread for those that had questions they wanted answers to in regards to these topics in a sort of non-debate format, since a lot of people find that antagonizing.

 

[PsychoSarah]

Thank you.

Here's another one:

Would rabbits in the Precambrian falsify evolution?

Rabbit fossils found in Precambrian rock layers would definitively falsify the timescale, which wreaks how most of the theorized processes of evolution work, so, in short, yes.

Currently, however, no such fossil has been found in the Precambrian rock layers, though there have been a few frauds.

 

[PsychoSarah]

If we came from primates, why are primates still around?

Simple:
1. We ourselves are primates.
2. We aren't the only progeny of ancient primates; that is to say, one species can have populations break off from each other, which then evolve over time into different species. This is fairly common, hence the variety of modern primate species.

 

[PsychoSarah]

Is there a perfect definition? If not, what is the problem with the ability to perfectly define the criteria?

We like to categorize nature into nice, little boxes, but nature simply doesn't work that way. For example, Species A and Species B could interbreed, as could Species B and Species C, but Species A and Species C can't breed with each other. Situations such as that make categorizing even living species, so it is no wonder that these classifications are argued over all the time. It gets even worse when coming up with classifications of extinct species via fossils.