This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on orchid
species.

I would guess that a cultivated orchid species might grow bigger and live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be adjusted
to be closer to ideal conditions than might occur in nature, if the grower
knows what they are doing. Also I know that plants within the species won't
be exactly the same, and the orchid grower might decide to cross two orchids
that are in the same species and share some trait that does not occur in all
orchids of this species to try to promote this trait which might have gotten
lost in the wild (where natural selection or chance might have caused this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

with regard to wolfs, cats and dogs, a word to learn about is neoteny. Used
with domestic cats and dogs the idea is that adult cats and dogs retain a
lot of personality traits common only to the puppies and kittens of similar
wild species. I guess it has made them easier to handle over the long
generations they have been associating with people. I saw a science show on
the Discovery channel once when I couldn't find a channel showing Star Trek
reruns.

Big subject with regard to orchid species judging. A lot of wild orchids
can't hold a candle to their line-bred cousins in captivity with regard to
judging standards. Judges are taught to consider the species normal habit
when judging it, but the process can almost not help but include certain
pre-judgments of what a beautiful flower looks like. Flame me, it's okay.
I can handle it.

"Orchids that have been bred in captivity for generations grow better in
pots than wild ones." That's quote but not mine. :-) Smart breeders do
not use plants for breeding if they are prone to disease, so one would think
that domestic populations that are generations old might be more disease
resistant. On the other hand, the environment we provide for them is so
protected that one would also thing they would not live long if some well
meaning person were to repatriate them into their native habitat.

I'll bet you get lots of replies to this topic.

Al
ne·ot·e·ny
NOUN:1. Retention of juvenile characteristics in the adults of a species. 2.
The attainment of sexual maturity by an organism still in its larval stage.


J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

with regard to wolfs, cats and dogs, a word to learn about is neoteny. Used
with domestic cats and dogs the idea is that adult cats and dogs retain a
lot of personality traits common only to the puppies and kittens of similar
wild species. I guess it has made them easier to handle over the long
generations they have been associating with people. I saw a science show on
the Discovery channel once when I couldn't find a channel showing Star Trek
reruns.

Big subject with regard to orchid species judging. A lot of wild orchids
can't hold a candle to their line-bred cousins in captivity with regard to
judging standards. Judges are taught to consider the species normal habit
when judging it, but the process can almost not help but include certain
pre-judgments of what a beautiful flower looks like. Flame me, it's okay.
I can handle it.

"Orchids that have been bred in captivity for generations grow better in
pots than wild ones." That's quote but not mine. :-) Smart breeders do
not use plants for breeding if they are prone to disease, so one would think
that domestic populations that are generations old might be more disease
resistant. On the other hand, the environment we provide for them is so
protected that one would also thing they would not live long if some well
meaning person were to repatriate them into their native habitat.

I'll bet you get lots of replies to this topic.

Al
ne·ot·e·ny
NOUN:1. Retention of juvenile characteristics in the adults of a species. 2.
The attainment of sexual maturity by an organism still in its larval stage.


J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

with regard to wolfs, cats and dogs, a word to learn about is neoteny. Used
with domestic cats and dogs the idea is that adult cats and dogs retain a
lot of personality traits common only to the puppies and kittens of similar
wild species. I guess it has made them easier to handle over the long
generations they have been associating with people. I saw a science show on
the Discovery channel once when I couldn't find a channel showing Star Trek
reruns.

Big subject with regard to orchid species judging. A lot of wild orchids
can't hold a candle to their line-bred cousins in captivity with regard to
judging standards. Judges are taught to consider the species normal habit
when judging it, but the process can almost not help but include certain
pre-judgments of what a beautiful flower looks like. Flame me, it's okay.
I can handle it.

"Orchids that have been bred in captivity for generations grow better in
pots than wild ones." That's quote but not mine. :-) Smart breeders do
not use plants for breeding if they are prone to disease, so one would think
that domestic populations that are generations old might be more disease
resistant. On the other hand, the environment we provide for them is so
protected that one would also thing they would not live long if some well
meaning person were to repatriate them into their native habitat.

I'll bet you get lots of replies to this topic.

Al
ne·ot·e·ny
NOUN:1. Retention of juvenile characteristics in the adults of a species. 2.
The attainment of sexual maturity by an organism still in its larval stage.


J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

Al wrote:

"Orchids that have been bred in captivity for generations grow better in
pots than wild ones." That's quote but not mine. :-) Smart breeders do
not use plants for breeding if they are prone to disease, so one would think
that domestic populations that are generations old might be more disease
resistant. On the other hand, the environment we provide for them is so
protected that one would also thing they would not live long if some well
meaning person were to repatriate them into their native habitat.

I'll bet you get lots of replies to this topic.



I'll bite...

Are there any good examples of orchids where the same species in cultivation


tends to be quite different in some significant way from its wild
counterpart?


Virtually all of them... Any cattleya which has been in
captivity for more than a couple generations is quite different from its
wild cousins. If nothing else, many breeders have intentionally
converted them to tetraploid. Line bred Phal 'aphrodite' (quotes mine,
because it is likely that the line bred ones have some hybrid
background) are very distinct from wild ones. Doritis pulcherrima is
quite cute in its native form, but you couldn't get one awarded today,
as the line bred ones have flowers that are several times bigger.
There is some debate in judging circles as to whether this is 'fair'.
No, it isn't fair if you are a wonderful wild collected flower and
competing against a line bred specimen. Sorry. But we don't grow
orchids to be fair, we grow them for nice flowers.

Why is line breeding so different than nature's breeding? Human
selection is different than natural selection. For example, if we see
an albino flower (and like it) we 'fix' the phenotype. Orchids are
designed to cross pollinate, not self pollinate. So, since you get a
copy of each gene (allele) from your parents, the albinistic allele can
be masked or diluted by the normal allele from the other parent. But
humans are persistant, and we will self that albino flower to try to get
offspring which are homozygous for the albinistic allele. Once we do
that, the phenotype is 'fixed'. In other words, if we self that albino
offspring, we can only get albino offspring. Natural selection would
have diluted that trait in the gene pool, since the vast majority of
potential mates have the gene for 'normal' color.

Anyway, we can do that for any trait. The human selection process
is actively directed, natural selection is not. This is why we have
terriers and St. Bernards - somebody wanted little dogs and somebody
else wanted big dogs, and selected appropriately. We've been mucking
about with everything for a long time. I bet you've never seen the wild
maize that our modern maize is bred from, and if you did you probably
wouldn't recognize it. Orchid breeders select for features they like
(vigor is certainly one of those), and don't breed with plants which
have 'inferior' features. One of the features that we absolutely must
select for is growth in captivity. If the plant can't grow from seed to
bloom, it can't be bred with. So we have no choice but to select for
plants that grow well in flask and pots. Wild collected plants are
often difficult to get 'viable' seed (seed that grows in flasks, anyway)
from, but once you get to the next generation, it is almost always much
easier.

Anyway, don't buy jungle collected plants. They are of absolutely
no use to the hobby orchid grower. They will not be 'better' (whatever
that means) than domesticated ones. That is not to say that they aren't
valuable from a genetic diversity standpoint. If you have bred all the
color out of your captive plants, you can't get it back unless you have
a wild plant which has the alleles for it. Line breeding is a one way
street.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

That was a wonderful Nova program, wasn't it!! Made me start wondering about
the same thing.

I know Alexis Pardo Isla once said that the orchids we grow are selected for
those that will grow in flasking medium. So that would be a basic
difference between those we have in captivity and the wild type.

K Barrett


"J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

"Rob Halgren" wrote in message
...
Al wrote:

"Orchids that have been bred in captivity for generations grow better in
pots than wild ones." That's quote but not mine. :-) Smart breeders do
not use plants for breeding if they are prone to disease, so one would
think
that domestic populations that are generations old might be more disease
resistant. On the other hand, the environment we provide for them is so
protected that one would also thing they would not live long if some well
meaning person were to repatriate them into their native habitat.

I'll bet you get lots of replies to this topic.



I'll bite...

Are there any good examples of orchids where the same species in
cultivation


tends to be quite different in some significant way from its wild
counterpart?


Virtually all of them... Any cattleya which has been in
captivity for more than a couple generations is quite different from its
wild cousins. If nothing else, many breeders have intentionally
converted them to tetraploid. Line bred Phal 'aphrodite' (quotes mine,
because it is likely that the line bred ones have some hybrid
background) are very distinct from wild ones. Doritis pulcherrima is
quite cute in its native form, but you couldn't get one awarded today,
as the line bred ones have flowers that are several times bigger.
There is some debate in judging circles as to whether this is 'fair'.
No, it isn't fair if you are a wonderful wild collected flower and
competing against a line bred specimen. Sorry. But we don't grow
orchids to be fair, we grow them for nice flowers.

Why is line breeding so different than nature's breeding? Human
selection is different than natural selection. For example, if we see
an albino flower (and like it) we 'fix' the phenotype. Orchids are
designed to cross pollinate, not self pollinate. So, since you get a
copy of each gene (allele) from your parents, the albinistic allele can
be masked or diluted by the normal allele from the other parent. But
humans are persistant, and we will self that albino flower to try to get
offspring which are homozygous for the albinistic allele. Once we do
that, the phenotype is 'fixed'. In other words, if we self that albino
offspring, we can only get albino offspring. Natural selection would
have diluted that trait in the gene pool, since the vast majority of
potential mates have the gene for 'normal' color.

Anyway, we can do that for any trait. The human selection process
is actively directed, natural selection is not. This is why we have
terriers and St. Bernards - somebody wanted little dogs and somebody
else wanted big dogs, and selected appropriately. We've been mucking
about with everything for a long time. I bet you've never seen the wild
maize that our modern maize is bred from, and if you did you probably
wouldn't recognize it. Orchid breeders select for features they like
(vigor is certainly one of those), and don't breed with plants which
have 'inferior' features. One of the features that we absolutely must
select for is growth in captivity. If the plant can't grow from seed to
bloom, it can't be bred with. So we have no choice but to select for
plants that grow well in flask and pots. Wild collected plants are
often difficult to get 'viable' seed (seed that grows in flasks, anyway)
from, but once you get to the next generation, it is almost always much
easier.

Anyway, don't buy jungle collected plants. They are of absolutely
no use to the hobby orchid grower. They will not be 'better' (whatever
that means) than domesticated ones. That is not to say that they aren't
valuable from a genetic diversity standpoint. If you have bred all the
color out of your captive plants, you can't get it back unless you have
a wild plant which has the alleles for it. Line breeding is a one way
street.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

There was an interesting comment in the Nova (PBS) program about how line
breeding in dogs makes them more susceptible to viruses and cancers,
something I've always heard, but never understood. Anyway, your comment and
one by Peter O'Byrne about how line breeding and hybrid lines in what are
supposedly species makes me wonder.

How identical *is* species DNA anyway?

Is the genome like a template? If one could put the entire DNA strands of a
species on an overhead projector acetate, could one overlay all the G-C and
A-T base pairs on top of one another would they all line up? Could you say
that any variation within that line-up would be something like 'different
colored eyes, and so same species' or 'different all together and so a
hybrid'? I mean, how can one isolate individual variation within a
species? And how would one know that the aberrant base pairs weren't
individual variation but the result of hybridization?

Who is to say what species DNA is? Lord knows there's enough bickering and
infighting amongst taxonomists who classify species according to set
international rules. Who would be the agency that would determine and stamp
approve what 'species DNA' looks like? And how would they know? What if
they missed a few individuals? Like if a Greater Alien Space Race came to
the Earth they'd think by preponderance of numbers that the human species
was Asian, and take that DNA as criteria of human-ness. The tiny Bushman
from the Kalihari Desert would be shit out of luck because they don't look
Asian. What then? Would The Aliens be justified in eating Bushmen because,
according to their definition of human-ness, they weren't human?

K Barrett

"K Barrett" wrote in message
news:xGQUb.186854$sv6.989995@attbi_s52...
[snip]
How identical *is* species DNA anyway?


This question gets quite close to the real issue. If rephrased to be, "Are
the genomes of two specimens of a given species identical," the answer must
be no unless the two specimens represent clones of the same organism. The
reason for this is that either the genome possessed by a given individual is
identical to that possessed by another organism of the same species or it
isn't. What both your question and my alteration of it presuppose we know
what a species is and how to determine whether or not two arbitrary
specimens are of the same species.

Given some idea of what a species is, however, a more useful question would
be, "How similar are the genomes possessed by any two individuals of a given
species likely to be?" That is, in fact, something that can be quantified.
Only clones (including all products of asexual reproduction but including
also identical twins - the products of a natural cloning process if you
like) will have identical genetic material. Modern taxonomy is based on
measures of similarity, not judgements that two given specimens are
identical.

The more fundamental question, which must be answered FIRST, is "What is a
species?" Without an answer to that question, it is not possible to form
rational judgements on any other taxonomic issue. And there is no such
definition in widespread use by taxonomists and that is the primary reason
why modern taxonomy is in such a mess; much to the chagrin of other
biologists and of horticulturalists alike.

It is useful to observe that, among the cases of which I am aware, it only
takes tiny genetic differences, in terms of percentage of genes having
different alleles, to produce enormous differences in phenotype (the
consequence of gene expression). The genetic material possessed by the
Inuit (also known as eskimos - to the best of my knowledge, they prefer to
be called Inuit), Dene, african bushmen and indoeuropeans is so similar, it
would be both difficult and tedious to measure the differences to an
acceptable degree of precision, and yet look at the diversity the existing
differences make in their respective phenotypes.

Does this help?

Cheers,

Ted

How identical *is* species DNA anyway?



Is the genome like a template? If one could put the entire DNA strands of a
species on an overhead projector acetate, could one overlay all the G-C and
A-T base pairs on top of one another would they all line up? Could you say
that any variation within that line-up would be something like 'different
colored eyes, and so same species' or 'different all together and so a
hybrid'? I mean, how can one isolate individual variation within a
species? And how would one know that the aberrant base pairs weren't
individual variation but the result of hybridization?



This _is_ actually my field, for once... And yes, the genome is a
template, if you aligned all of the DNA for all of the individuals in a
species, it would line up pretty darn well. The last estimate I heard
for the human genome was one SNP (single nucleotide polymorphism) for
every 1000 bases or so. Not every SNP (in fact very few) actually does
anything significant to a gene. We don't know enough now to read the
genome quite like a book. The main problem is that there are very few
single locus traits, most are multiple loci working in various degrees
of collaboration. It isn't easy to read a book when the sentences
bounce around between chapters and the grammar isn't entirely worked out.

How do you know the difference between individual variation and
hybridization? In a grossly oversimplified view: Most of the genes
for two closely related species will be very close in sequence. This is
as it should be, if they are derived from a common ancestor. But, if
you look at the right genes, there should be a consistent difference in
the sequence between two species. If you know that difference, then it
is easy to look and see if an organism has two copies of organism A's
gene, two copies of organism B's gene, or one of each. You need to
look at many different genes, usually. Actually, a variation of this is
exactly how a paternity test works (children are hybrids too).

Note that is only the closely related things that we have a problem
with... We can all tell that Paph. rothschildianum and Paph. armeniacum
are distinct species. We can get a pretty good idea that Paph.
Dollgoldii is a hybrid. We don't need DNA evidence for that...

Who is to say what species DNA is? Lord knows there's enough bickering and
infighting amongst taxonomists who classify species according to set
international rules. Who would be the agency that would determine and stamp
approve what 'species DNA' looks like? And how would they know? What if
they missed a few individuals? Like if a Greater Alien Space Race came to
the Earth they'd think by preponderance of numbers that the human species
was Asian, and take that DNA as criteria of human-ness. The tiny Bushman
from the Kalihari Desert would be shit out of luck because they don't look
Asian. What then? Would The Aliens be justified in eating Bushmen because,
according to their definition of human-ness, they weren't human?



I actually have a talk about this worked up for orchids... The
answer is that there is no magic answer when you use DNA, any more than
there is when you use phenotypic markers for taxonomy. But, you can get
good estimates of how far apart things are. The boundaries are always a
mess, and always will be. DNA is just another tool. A powerful tool.
Somebody still needs to decide just how far apart is far enough to
qualify as a separate species.

What makes something a distinct species is genetic isolation and
time. Given enough of each, you don't fancy science to tell them
apart. It is those fuzzy edges that kick you in the head. When Al's
aliens come to pick him up, they will realize that his DNA is 99.9999%+
similar to both the Kalihari bushman and the Eskimo. It is
extraordinarily similar to that of a chimpanzee. It is remarkably
similar (in both sequence and the organization of the genes on the
chromosomes) to the DNA of a mouse. It is somewhat (disturbingly)
similar to the sequence and organization of the genes on the chromosome
of the zebra fish. The farther apart we get, the more difference there
is, but there is still remarkable conservation.

Besides, we all know that the aliens (or monsters) eat the cute,
mysteriously underdressed girls, who get separated from their group of
friends by strange plot twists. I learned that from the movies.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

Give me a day or two to mull this over and ask (hopefully an intelligent)
question.

Thanks for your response

K
"Ted Byers" wrote in message
. ..

"K Barrett" wrote in message
news:xGQUb.186854$sv6.989995@attbi_s52...
[snip]
How identical *is* species DNA anyway?


This question gets quite close to the real issue. If rephrased to be,
"Are
the genomes of two specimens of a given species identical," the answer
must
be no unless the two specimens represent clones of the same organism. The
reason for this is that either the genome possessed by a given individual
is
identical to that possessed by another organism of the same species or it
isn't. What both your question and my alteration of it presuppose we know
what a species is and how to determine whether or not two arbitrary
specimens are of the same species.

Given some idea of what a species is, however, a more useful question
would
be, "How similar are the genomes possessed by any two individuals of a
given
species likely to be?" That is, in fact, something that can be
quantified.
Only clones (including all products of asexual reproduction but including
also identical twins - the products of a natural cloning process if you
like) will have identical genetic material. Modern taxonomy is based on
measures of similarity, not judgements that two given specimens are
identical.

The more fundamental question, which must be answered FIRST, is "What is a
species?" Without an answer to that question, it is not possible to form
rational judgements on any other taxonomic issue. And there is no such
definition in widespread use by taxonomists and that is the primary reason
why modern taxonomy is in such a mess; much to the chagrin of other
biologists and of horticulturalists alike.

It is useful to observe that, among the cases of which I am aware, it only
takes tiny genetic differences, in terms of percentage of genes having
different alleles, to produce enormous differences in phenotype (the
consequence of gene expression). The genetic material possessed by the
Inuit (also known as eskimos - to the best of my knowledge, they prefer to
be called Inuit), Dene, african bushmen and indoeuropeans is so similar,
it
would be both difficult and tedious to measure the differences to an
acceptable degree of precision, and yet look at the diversity the existing
differences make in their respective phenotypes.

Does this help?

Cheers,

Ted

Give me a day or two to mull this over and ask (hopefully an intelligent)
question.

Thanks for your response

K
"Ted Byers" wrote in message
. ..

"K Barrett" wrote in message
news:xGQUb.186854$sv6.989995@attbi_s52...
[snip]
How identical *is* species DNA anyway?


This question gets quite close to the real issue. If rephrased to be,
"Are
the genomes of two specimens of a given species identical," the answer
must
be no unless the two specimens represent clones of the same organism. The
reason for this is that either the genome possessed by a given individual
is
identical to that possessed by another organism of the same species or it
isn't. What both your question and my alteration of it presuppose we know
what a species is and how to determine whether or not two arbitrary
specimens are of the same species.

Given some idea of what a species is, however, a more useful question
would
be, "How similar are the genomes possessed by any two individuals of a
given
species likely to be?" That is, in fact, something that can be
quantified.
Only clones (including all products of asexual reproduction but including
also identical twins - the products of a natural cloning process if you
like) will have identical genetic material. Modern taxonomy is based on
measures of similarity, not judgements that two given specimens are
identical.

The more fundamental question, which must be answered FIRST, is "What is a
species?" Without an answer to that question, it is not possible to form
rational judgements on any other taxonomic issue. And there is no such
definition in widespread use by taxonomists and that is the primary reason
why modern taxonomy is in such a mess; much to the chagrin of other
biologists and of horticulturalists alike.

It is useful to observe that, among the cases of which I am aware, it only
takes tiny genetic differences, in terms of percentage of genes having
different alleles, to produce enormous differences in phenotype (the
consequence of gene expression). The genetic material possessed by the
Inuit (also known as eskimos - to the best of my knowledge, they prefer to
be called Inuit), Dene, african bushmen and indoeuropeans is so similar,
it
would be both difficult and tedious to measure the differences to an
acceptable degree of precision, and yet look at the diversity the existing
differences make in their respective phenotypes.

Does this help?

Cheers,

Ted

Thanks for your response. It'll take me a while to assimilate it (I know,
its futile...)

But a follow up question is coming...

after I've had a few more Cosmopolitans

K
"Rob Halgren" wrote in message
...

How identical *is* species DNA anyway?



Is the genome like a template? If one could put the entire DNA strands
of a
species on an overhead projector acetate, could one overlay all the G-C
and
A-T base pairs on top of one another would they all line up? Could you
say
that any variation within that line-up would be something like 'different
colored eyes, and so same species' or 'different all together and so a
hybrid'? I mean, how can one isolate individual variation within a
species? And how would one know that the aberrant base pairs weren't
individual variation but the result of hybridization?



This _is_ actually my field, for once... And yes, the genome is a
template, if you aligned all of the DNA for all of the individuals in a
species, it would line up pretty darn well. The last estimate I heard
for the human genome was one SNP (single nucleotide polymorphism) for
every 1000 bases or so. Not every SNP (in fact very few) actually does
anything significant to a gene. We don't know enough now to read the
genome quite like a book. The main problem is that there are very few
single locus traits, most are multiple loci working in various degrees
of collaboration. It isn't easy to read a book when the sentences
bounce around between chapters and the grammar isn't entirely worked out.

How do you know the difference between individual variation and
hybridization? In a grossly oversimplified view: Most of the genes
for two closely related species will be very close in sequence. This is
as it should be, if they are derived from a common ancestor. But, if
you look at the right genes, there should be a consistent difference in
the sequence between two species. If you know that difference, then it
is easy to look and see if an organism has two copies of organism A's
gene, two copies of organism B's gene, or one of each. You need to
look at many different genes, usually. Actually, a variation of this is
exactly how a paternity test works (children are hybrids too).

Note that is only the closely related things that we have a problem
with... We can all tell that Paph. rothschildianum and Paph. armeniacum
are distinct species. We can get a pretty good idea that Paph.
Dollgoldii is a hybrid. We don't need DNA evidence for that...

Who is to say what species DNA is? Lord knows there's enough bickering
and
infighting amongst taxonomists who classify species according to set
international rules. Who would be the agency that would determine and
stamp
approve what 'species DNA' looks like? And how would they know? What if
they missed a few individuals? Like if a Greater Alien Space Race came
to
the Earth they'd think by preponderance of numbers that the human species
was Asian, and take that DNA as criteria of human-ness. The tiny Bushman
from the Kalihari Desert would be shit out of luck because they don't
look
Asian. What then? Would The Aliens be justified in eating Bushmen
because,
according to their definition of human-ness, they weren't human?



I actually have a talk about this worked up for orchids... The
answer is that there is no magic answer when you use DNA, any more than
there is when you use phenotypic markers for taxonomy. But, you can get
good estimates of how far apart things are. The boundaries are always a
mess, and always will be. DNA is just another tool. A powerful tool.
Somebody still needs to decide just how far apart is far enough to
qualify as a separate species.

What makes something a distinct species is genetic isolation and
time. Given enough of each, you don't fancy science to tell them
apart. It is those fuzzy edges that kick you in the head. When Al's
aliens come to pick him up, they will realize that his DNA is 99.9999%+
similar to both the Kalihari bushman and the Eskimo. It is
extraordinarily similar to that of a chimpanzee. It is remarkably
similar (in both sequence and the organization of the genes on the
chromosomes) to the DNA of a mouse. It is somewhat (disturbingly)
similar to the sequence and organization of the genes on the chromosome
of the zebra fish. The farther apart we get, the more difference there
is, but there is still remarkable conservation.

Besides, we all know that the aliens (or monsters) eat the cute,
mysteriously underdressed girls, who get separated from their group of
friends by strange plot twists. I learned that from the movies.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

Kathy,
Actually I did not see the Nova program myself, just heard someone talk
about it. Sometimes (like this one) I regret not having a TV antenna or
cable. However, most of the time I think we've made a wise choice: I know if
I had TV reception I would spend hours watching it, and then I couldn't
spend all this time here on rgo, and read as many books as I do, etc.
Joanna

"K Barrett" wrote in message
news:z6QUb.186773$sv6.989867@attbi_s52...
That was a wonderful Nova program, wasn't it!! Made me start wondering
about
the same thing.

I know Alexis Pardo Isla once said that the orchids we grow are selected
for
those that will grow in flasking medium. So that would be a basic
difference between those we have in captivity and the wild type.

K Barrett


"J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what
the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as
well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and
live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the
grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused
this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or
your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

Kathy,
Actually I did not see the Nova program myself, just heard someone talk
about it. Sometimes (like this one) I regret not having a TV antenna or
cable. However, most of the time I think we've made a wise choice: I know if
I had TV reception I would spend hours watching it, and then I couldn't
spend all this time here on rgo, and read as many books as I do, etc.
Joanna

"K Barrett" wrote in message
news:z6QUb.186773$sv6.989867@attbi_s52...
That was a wonderful Nova program, wasn't it!! Made me start wondering
about
the same thing.

I know Alexis Pardo Isla once said that the orchids we grow are selected
for
those that will grow in flasking medium. So that would be a basic
difference between those we have in captivity and the wild type.

K Barrett


"J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what
the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as
well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and
live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the
grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused
this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or
your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna

Kathy,
Actually I did not see the Nova program myself, just heard someone talk
about it. Sometimes (like this one) I regret not having a TV antenna or
cable. However, most of the time I think we've made a wise choice: I know if
I had TV reception I would spend hours watching it, and then I couldn't
spend all this time here on rgo, and read as many books as I do, etc.
Joanna

"K Barrett" wrote in message
news:z6QUb.186773$sv6.989867@attbi_s52...
That was a wonderful Nova program, wasn't it!! Made me start wondering
about
the same thing.

I know Alexis Pardo Isla once said that the orchids we grow are selected
for
those that will grow in flasking medium. So that would be a basic
difference between those we have in captivity and the wild type.

K Barrett


"J Fortuna" wrote in message
...
This is not off topic even though the beginning may sound like it is, so
please bear with me:

I recently heard that when wolves are tamed, one of the side-effects of
taming is that their fur turns a lighter color. I forget exactly what
the
explanation was, but I think it was something like the same chemical
substance being responsible for anxiety/fear/wildness in character as
well
as darkness of fur.

Leap in thinking from wolves to orchid plants ...

This made me wonder about some of the effects that cultivation has on
orchid
species.

I would guess that a cultivated orchid species might grow bigger and
live
longer than its wild counterpart of the same species, etc. That at least
would seam logical to me, since the cultivated species are likely to be
fertilized more regularly, and the environment is more likely to be
adjusted
to be closer to ideal conditions than might occur in nature, if the
grower
knows what they are doing. Also I know that plants within the species
won't
be exactly the same, and the orchid grower might decide to cross two
orchids
that are in the same species and share some trait that does not occur in
all
orchids of this species to try to promote this trait which might have
gotten
lost in the wild (where natural selection or chance might have caused
this
trait to not be propagated).

Any other ideas? Either based on your experience, your knowledge, or
your
hypothesizing on this subject?

I would be interested in finding out more. I wonder if there are any
effects
that cultivation has had on orchid species that are less obvious/logical
(similar to the lightening of fur in wolves, which I would never have
guessed if I had not learned about it).

Are there any good examples of orchids where the same species in
cultivation
tends to be quite different in some significant way from its wild
counterpart?

Thanks,
Joanna