Genetics Question

[Risen Tree]

Let's say we have 3 different races from a common species: A, B, and C.

A can mate with B.
B can mate with C.
A cannot mate with C.

How many species exist here, one or three?

 

[Late_Cretaceous]

That is a common phenomenon in the natural world. It is kind of like trying to define "warm" from "hot" in relation to the weather.

The short answer to your question is "it depends".

I can think of one example of where they are all considered one species. One species of frog with a range over much of North America. Although they are considered one species, individuals from the north cannot produce viable offspring from the south end of the range.

In another case, of salamanders in California, they are considered different species.

In both types of case, it is called a cline. Where the differentiation between one species and another is very difficult to make because it is such a continuum.

 

[Bushido216]

Let's say we have 3 different races from a common species: A, B, and C.

A can mate with B.
B can mate with C.
A cannot mate with C.

How many species exist here, one or three?

I would say three.

It sounds like phyletic speciation except that the intermediates didn't die out.

Interesting.

 

[Risen Tree]

Thanks.

Hm, I meant to post this in an open forum...can a mod please move this to there?

 

[billwald]

"Race" is equivalent to "breed." All human races are the same specie.

 

[Gander]

Let's say we have 3 different races from a common species: A, B, and C.

A can mate with B.
B can mate with C.
A cannot mate with C.

How many species exist here, one or three?

Technically this is not really a genetics question, it is a labeling question. How do you define a species?

I would tend to agree with the way you have answered your own question by saying they are one common species.

The genetics of your example is hard to comment on because A, B, and C are not known, but hypothetical. However, let us assume that "A" is the original existing before B or C. As it is generally agreed between both creationist and evolutionist there is no fixity of the species, what we are looking for is a method for speciation.
We can rule out phyletic speciation as we know that there is no mechanism by which new genetic material can be added. That leaves us with the commonly witnessed horizontal evolution within a species.
The answer to why there is an A, B and C is basically the rearrangement of genetic material or Chromosome translocation.

 

[notto]

Rising tree, you might want to google 'ring species'. This is an interesting topic to look at. There are several bird species that for ring species just like you describe at certain elevations around mountain tops. As the species expanded around a mountain, by the time the got to the other side and surrounded it, there was enough variation at the end that they could not or would not mate with those at the beginning of the 'ring'.

Now, if an evironment change comes and wipes out the middle of the ring, you have now separated the population into two distinct species. This is one way that speciation can (and does) occur.

 

[Risen Tree]

Rising tree, you might want to google 'ring species'. This is an interesting topic to look at. There are several bird species that for ring species just like you describe at certain elevations around mountain tops. As the species expanded around a mountain, by the time the got to the other side and surrounded it, there was enough variation at the end that they could not or would not mate with those at the beginning of the 'ring'.

Now, if an evironment change comes and wipes out the middle of the ring, you have now separated the population into two distinct species. This is one way that speciation can (and does) occur.

I did so and came up with the following:

http://www.cs.colorado.edu/~lindsay/creation/ring_species.html
http://www.pbs.org/wgbh/evolution/library/05/2/l_052_05.html

Judging from what you guys and these sites are saying, as long as the links remain intact, the creatures within are treated as a single species. Breaking the link causes speciation.

 

[lucaspa]

I did so and came up with the following:

http://www.cs.colorado.edu/~lindsay/creation/ring_species.html
http://www.pbs.org/wgbh/evolution/library/05/2/l_052_05.html

Judging from what you guys and these sites are saying, as long as the links remain intact, the creatures within are treated as a single species. Breaking the link causes speciation.

That depends on whether the intermediates do mate. Your hypothetical said they could but didn't say whether they actually did.

The Biological Species Concept depends on 1) actual mating and 2) full fertility and viability of the hybrids. Take the case of lions and tigers. Yes, they can mate in captivity and produce offspring. But, they don't mate in the wild and the offspring are not fertile with either lions or tigers.

What your example shows is that any defintion of species can never be precise. There will always be gray areas where we don't know whether we have 1 species or 2 precisely because evolution is true and species transform into new species over time. During that transformation process, there is always going to be a time where the species are separating but not quite separate.

 

[Godzman]

Well I do know my family are humans, and well my dog's family are dogs and my cat's family are cats.

Could I be mistaken

 

[lucaspa]

Well I do know my family are humans, and well my dog's family are dogs and my cat's family are cats.

Could I be mistaken

If you go far enough back in time -- about 130 million years -- yes, you are mistaken. Dogs and cats are our evolutionary cousins. We and they share a common ancestor, just like you and your human first cousins share a common ancestor -- your grandparents. Is that so hard to grasp?

 

[Godzman]

If you go far enough back in time -- about 130 million years -- yes, you are mistaken. Dogs and cats are our evolutionary cousins. We and they share a common ancestor, just like you and your human first cousins share a common ancestor -- your grandparents. Is that so hard to grasp?

its hard to grasp how I could have been a plate of goo

 

[lucaspa]

its hard to grasp how I could have been a plate of goo

You weren't. However, the first life did arise thru chemical processes and the first life was one-celled.

Can you imagine yourself being one-celled? Yet for a time right after conception, you were. Can you imagine yourself with gill arches? Yet during development you had them. Can you imagine yourself with a stubby tail? During development you had that, too.

Muslims have a hard time grasping that God can be three personas in one ousia. In fact, many Christians had a hard time grasping that when it was first proposed, also.

What you have stated is the Argument from Personal Incredulity. It is not a good argument for determining truth.

 

[Godzman]

You weren't. However, the first life did arise thru chemical processes and the first life was one-celled.

Can you imagine yourself being one-celled? Yet for a time right after conception, you were. Can you imagine yourself with gill arches? Yet during development you had them. Can you imagine yourself with a stubby tail? During development you had that, too.

Muslims have a hard time grasping that God can be three personas in one ousia. In fact, many Christians had a hard time grasping that when it was first proposed, also.

What you have stated is the Argument from Personal Incredulity. It is not a good argument for determining truth.

How can a Christian reject the word of God when he clearly states that he made man from the dust, it can not be translated anyother way. Those who try are mistaken the hebrew leaves little room for that.

And if you reject Genesis why do you follow Christ who accepted the law of the bible and revered the words of God because he was the very Word of God

 

[lucaspa]

How can a Christian reject the word of God when he clearly states that he made man from the dust, it can not be translated anyother way.

I notice that you have given up discussing the science. You have retreated instead into "you must take Genesis literally". But we don't have to take Genesis literally. Especially when God tells us both in His Creation and in the text that a literal interpretation is the wrong one.

You invoke Genesis 2. But Genesis 1 says God made man by speaking him into existence: "Let us make". Also, in Genesis 1 the Hebrew used for "man" and "woman" is the plural of those terms, so God is making both men and women at the same time. Genesis 2 has one man, then animals and birds, and then one woman.

So, what we have is two "clearly states" that contradict each other. This tells us that neither creation story was ever meant to be read literally.

Now, no one is rejecting these verses. Instead, we are simply not reading them as literal history. We are looking for the theological truths in the passages. There is more than one type of truth. Something can be theologically true but not true as history.

And if you reject Genesis why do you follow Christ who accepted the law of the bible and revered the words of God because he was the very Word of God

Listen carefully: NO ONE IS REJECTING GENESIS. What we are rejecting is the man-made literal interpretation. And we are not even talking about all of Genesis, but simply Genesis 1-11.

Instead, we are saying that there are very valuable theological truths in each creation story. Truths that Biblical literalists miss because they are too busy trying to force their views on the Bible and on God. These theological truths work just as well in modern science as they do in the Babylonian science in which the OT is set. The science of the OT is wrong, but not the theology.

As to Jesus accepting the "law" of the Bible, all of his ministry was rejecting a literal reading of that Law. I find it ironic that Biblical literalists invoke Jesus when arguing for a literal reading of Genesis 1-11. In Mark 10 and Matthew 19 Jesus specifically says that one of the laws in the OT is out and out wrong!

 

[DatingSmarts]

what if it wasn't 'dust' but was really genetic material

hence the name of the book: GENEsis

the genetic material is as small as a speck of dust

 

[lucaspa]

what if it wasn't 'dust' but was really genetic material

hence the name of the book: GENEsis

the genetic material is as small as a speck of dust

It's nice that Genesis contains the word "gene" in English, but remember that the OT was written in Hebrew. There was no Hebrew word for gene then. This is inserting a meaning into the text from a translation to English when the Bible was inspired to the writers in Hebrew. Doesn't seem right.

 

[Bulldog]

what if it wasn't 'dust' but was really genetic material

hence the name of the book: GENEsis

the genetic material is as small as a speck of dust

The word "Genesis" does not come from the word "gene".

 

[DatingSmarts]

it is convenient though isn't it

what does 'genesis' mean and where does it come from?

likewise, what does 'gene' mean and where does it come from?

 

[DatingSmarts]

so far, I like my biological interpretation...i bet God does too....such a clever creator that guy