Let's start at the beginning? maybe?

[The Hammer]

OK, let me guess -- all the hominids that supposedly came before homosapiens are extinct...?

They are now. The last to die out were the Neanderthals.

 

[Daemon Sophic]

Maybe the term gene pool is not a good one, because I do not understand. So...I think I'm giving up on understanding it.

Here is a gene pool. It filled with balls, and the balls are all of the same species since they are balls, and balls can reproduce with one another. However, various groups of balls have many of the same characteristics as one another, and their colors appear similar. That is because their genetics are similar.

Historically, different regions of the Earth have balls of one color or another and only on the borderlands do they rarely mix (or interbreed) to create balls with new/unusual combination colors. But even the mixed color balls are still in the same gene pool as long as they remain balls.

 

[Subduction Zone]

So the question now is about those said hominids(?) that came before homosapiens, and which are now extinct. OK, let me guess -- all the hominids that supposedly came before homosapiens are extinct...?

Some of them became us. "Species" is name that is attached to a population over varying amount of time. We are still the same population as Homo erectus, but because since they were identified as their own species the members of that population that became us have changed quite a bit. Species names are a bit arbitrary as to when they begin and when they end so there will always be debate about that, but once again, that is due to the nature of evolution.

 

[LuisDantas]

(...) I do not understand what is meant by "that genetic material is fairly constant within any given person." (Fairly constant? You mean it can change within a person?)

It can, for at least three reasons.

1. Random mutation due to transcription errors. In essence, flaws in the process of duplication of cells.

2. Mutagenic action of radiation or chemical agents.

3. Diseases, notably cancer.

However, those changes are usually localized, generally not all that remarkable, and are not hereditary - unless the egg or sperm cells are themselves affected, that is.

 

[YoursTrue]

It can, for at least three reasons.

1. Random mutation due to transcription errors. In essence, flaws in the process of duplication of cells.

2. Mutagenic action of radiation or chemical agents.

3. Diseases, notably cancer.

However, those changes are usually localized, generally not all that remarkable, and are not hereditary - unless the egg or sperm cells are themselves affected, that is.

I give up. Way beyond me right now. Thank you for trying and very politely, too.

 

[sayak83]

@LuisDantas OK, so I have been doing some reading about ancient DNA and Neanderthals and find it hard to understand. I'm not saying you can help me, and I certainly thank you for trying. Because it really does get for me hard to understand. But here's what it says: "Most human sequences differ from each other by an average of 8.0 substitutions, while the human and chimpanzee sequences differ by about 55.0 substitutions. The Neanderthal and modern human sequences differed by approximately 27.2 substitutions." So I'm ready to give up because I can't even know what they mean by "most human sequences differ from each other, etc." By an average of 8.0 substitutions. 8.0 substitutions? What does that mean? So most likely it's a losing prospect to educate me on these things although it would be nice but I think it's beyond my ken right now. All I can say is thanks for trying. Ancient DNA and Neanderthals.

Internet links is an absolutely terrible way to understand anything, particularly a subject domain as big as evolutionary biology.
Can you not buy a book?

 

[blü 2]

Let me dust off my old Evolution Summary once again ─


Human evolution goes –
from the most basic form of life (protobionts, presently undefined)

to the single cell (Prokaryota) 3.7 bya
to nucleated multicelled (Eukaryota) [though some say Eu- was before or simultaneous with Pro-] 1.7 bya
to bilateral symmetry (Bilateria) ›555 mya
to a stomach with two openings [mouth and anus] (Deuterostomia) ›555 mya
to a notochord [‘spinal chord’] (Chordata) ›555 mya
to a backbone (Vertebrata) ›525 mya
— Ordovician - Silurian Extinction 440–450 mya
to a movable lower jaw (Gnathostomata) ›385 mya
to four legs (Tetrapoda) ›385 mya
— Late Devonian Extinction From ~360 to 375 mya
to eggs with water retention suitable for dry land (Amniota) ›340 mya
to eye sockets each with a single opening into the skull (Synapsida) ›324 mya
to mammal-like reptiles (Therapsida) ~274 mya
to ‘dog teeth’ (Cynodontia) ~260 mya
— Permian-Triassic Extinction 251 mya
to milk glands (Mammalia) ~200 mya
to vivipars and monotremes (Theriiformes) ›160 mya
to modern vivipars (Holotheria)
to proto-placentals and marsupials (Theria)
to placentals and certain extinct non-marsupials (Eutheria) ›160 mya
to placentals (Placentalia) ~110 mya
to all mammals except the Xenarthra [sloth, armadillo, anteater] (Epitheria) ~100 mya
to bats, primates, treeshrews (Archonta) ~100 mya
— Cretaceous-Tertiary Extinction 65.5 mya
to tarsiers, monkeys, apes (Haplorrhini) ~63 mya
to New and Old World monkeys and apes (Simiiformes) ~40 mya
to Old World monkeys and gibbons (Catarrhini) ~35 mya
to apes [great apes and gibbons] (Hominoidea) ~29 mya
to hominids / great apes [orangutans, gorillas, chimps, Homo] (Hominidae) ~25 mya
to hominins [gorillas, chimps, Homo, H. floresiensis, H. Denisova] (Homininae) ~4.5 mya
to Homo [H. sapiens, H. Neanderthalis, ] (Homo) ~2.4 mya
to Homo sapiens [Homo sapiens Idaltu, Homo sapiens sapiens] (Homo sapiens) 250 kya
to Homo sapiens sapiens.

So our ancestors separated from the fish line about 385 mya, came ashore maybe 365 mya, became mammals maybe 275 mya, primates maybe 100 mya, then hominids say 25 mya, genus Homo say 2.5 mya, Y-chromosomal Adam maybe 250 kya, mitochondrial Eve maybe 150 kya, and here we are.

 

[Heyo]

I give up. Way beyond me right now. Thank you for trying and very politely, too.

It's not that important at this time. The term "gene pool" is technically genetics, which is not evolution, but an assisting side field. We only know about genes for less than 100 years, while the ToE is over 150 years old. But Darwin predicted genetics, so it was a great success of the theory when chromosomes were found.

 

[YoursTrue]

I have bought books, one a textbook, but again I had too many questions and the textbook didn't answer. I can, however, go to the library, so I will.

Internet links is an absolutely terrible way to understand anything, particularly a subject domain as big as evolutionary biology.
Can you not buy a book?

 

[YoursTrue]

It's not that important at this time. The term "gene pool" is technically genetics, which is not evolution, but an assisting side field. We only know about genes for less than 100 years, while the ToE is over 150 years old. But Darwin predicted genetics, so it was a great success of the theory when chromosomes were found.

I think part of the problem is with the term gene pool. Because I envision a big mass of genes in a pool type thing. So I think a gene pool is that which relates only to the particular species. ?

 

[sayak83]

I have bought books, one a textbook, but again I had too many questions and the textbook didn't answer. I can, however, go to the library, so I will.

Which textbook?

 

[Balthazzar]

At a given time and place, you mean?

If you're isolated to a particular geographical location, then those living in that particular location. Mobility increases the number of people across geographical locations. So, to put it plainly, yes.

 

[TagliatelliMonster]

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

Instead of fish, try "chordates".
As for evidence, try DNA.

 

[TagliatelliMonster]

That seems like a fair response. I will reserve my comment on that. But it seems fair enough. And who knows what type of fish is said to have developed fins that grew to be like little legs?

Tiktaalik.

 

[TagliatelliMonster]

As I expected, this thread just disappoints.


Not that I ever was so naive to think it would go any other way off course.

 

[Heyo]

As I expected, this thread just disappoints.


Not that I ever was so naive to think it would go any other way off course.

My expectations, based on prior experiences, have not been disappointed. We have a mostly friendly and informative discussion that has stayed on topic for 8 pages now. That is something.

 

[TagliatelliMonster]

My expectations, based on prior experiences, have not been disappointed. We have a mostly friendly and informative discussion that has stayed on topic for 8 pages now. That is something.

Ow, yes.

I was referring to the seemingly promising intentions in the OP.

 

[LuisDantas]

Ow, yes.

I was referring to the seemingly promising intentions in the OP.

Maybe you jumped the gun a little?

 

[LuisDantas]

Internet links is an absolutely terrible way to understand anything, particularly a subject domain as big as evolutionary biology.
Can you not buy a book?

No kidding. I could not make head or tails of the page from which I took the picture that I used a few posts ago.

These things can be awfully confusing if we do not take care to consolidate the basic concepts.

 

[LuisDantas]

I think part of the problem is with the term gene pool. Because I envision a big mass of genes in a pool type thing.

That is not too far off the mark. As it happens, the pool is a population of living specimens.

So I think a gene pool is that which relates only to the particular species. ?

Yes and no. It is, but there are two complications.

1. Species are a fairly artificial concept, hard to truly delimit. Cats Dogs sometimes breed with wolves, horse with donkeys, tigers with lions. That is not usually of interest, but it depends on what we are trying to follow.

2. Speciation (the arising of new species) can only happen from inside a previously existing species.