What is adaptation?

On Sat, 11 Oct 2003 16:06:33 +0000 (UTC), [email hidden]

Quoted message said:

Popular writers often use the word adapt to imply passing on something that was not inherited, but
I think this smacks of Lamark.

So in the context of evolution, what is adaptation?

[moderator's note: This appeared in the management account mail queue (evolution-request, rather
than evolution), but it seems obvious it was intended for posting. As the author includes no
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as is. - JAH]

John Sutherland Phone & Fax +61 2 4683 1511 9 Meryla Street, Couridjah NSW 2571 Australia

Adaptation is a very general term for a change in a cell, an organism, or a population (species)
over time to adjust or modify some aspect of its behavior or function to the environment.

There is sensory adaptation where a sensory neuron ceases to respond (or responds more weakly) to a
sustained stimulus. The time scale may be on the order of seconds. There is physiological adaptation
to environmental circumstances that occurs on the time scale of seconds or minutes to days and
months. There is evolutionary adaptation that occurs over generations and is expressed as changes in
the genetic information.

So when you say "popular writers often use the word..." are you meaning only the latter notion, the
evolutionary notion, or are you including all the myriad other uses of the notion of adaptation? I
have never heard of the usage referring to "passing on something", though. Could you provide some
examples (with citations of source)?

You do also realize, of course, that many "popular writers" are simply careless or even incorrect in
their use of scientific notions.

In message <[email hidden]>, [email hidden] writes

Quoted message said:

Popular writers often use the word adapt to imply passing on something that was not inherited, but
I think this smacks of Lamark.

So in the context of evolution, what is adaptation?

Yes, very perceptive of you. If we replace the word adaptation with exploitation then it may provide
a better understanding of the past 4.5 billion years.

The Universe is a cruel host.
--
The Evolution earthpoetry.demon.co.ukearthpoetry.demon.co.ukOpen ↗ RC

[email hidden] wrote or quoted:

Quoted message said:

Popular writers often use the word adapt to imply passing on something that was not inherited, but
I think this smacks of Lamark.

So in the context of evolution, what is adaptation?

``ad·ap·ta·tion:

Biology. An alteration or adjustment in structure or habits, often hereditary, by which a species
or individual improves its condition in relationship to its environment.''

- dictionary.reference.comsearchOpen ↗

The term is also commonly used to describe the results of the process.
--
__________
|im |yler timtyler.orgtimtyler.orgOpen ↗ [email hidden] Remove lock to reply.

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

Popular writers often use the word adapt to imply passing on something that was not inherited, but
I think this smacks of Lamark.

So in the context of evolution, what is adaptation?

In the simplist form, it's a form of mutation. A kind of mutation which is better (in terms of
survival) than the others. Thus the most fitted mutated trait out survives other mutations.

<< Yes, very perceptive of you. If we replace the word adaptation with exploitation then it may
provide a better understanding of the past 4.5 billion years.

The Universe is a cruel host.
--
The Evolution earthpoetry.demon.co.ukearthpoetry.demon.co.ukOpen ↗ RC

Quoted message said:

Quoted message said:

I don't think that is accurate - at least half of all aspects of life are symbiotic which includes
any cell with mitochondria, or chloroplasts or any multicell being. Bacteria that can use nitrogen
promote all life indirectly as do photosynthesizers. Also all social behavior etc. This dog eat dog
view of life is mostly a male opinion and in my 4 options is definetly option 2 - or in psychology -
look at the work of K. Horney and look at her description of the disorder she labels as "Moves
Against Others"

IMO we are anthropomorphing biology when we claim it is all violent conflict. And more importantly
it just isn't true.

R. Norman answers John Sutherland's question:

Quoted message said:

Quoted message said:

So in the context of evolution, what is adaptation?

Adaptation is a very general term for a change in a cell, an organism, or a population (species)
over time to adjust or modify some aspect of its behavior or function to the environment.

The best definition of "adaptation" is the word itself. It literally means "towards aptness," which
is often written as "towards fitness," although I much prefer the phrase "towards appropriateness."
This latter phrase captures in two words the crux of what Darwin meant by the word.

Everything about the physical process of evolutionary adaptation is a movement across an adaptive
topography towards a condition of increasingly greater behavioral appropriateness in the
statistically expected phenotypes produced by an evolving lineage.

Quoted message said:

There is sensory adaptation where a sensory neuron ceases to respond (or responds more weakly) to a
sustained stimulus. The time scale may be on the order of seconds. There is physiological
adaptation to environmental circumstances that occurs on the time scale of seconds or minutes to
days and months. There is evolutionary adaptation that occurs over generations and is expressed as
changes in the genetic information.

That's certainly true enough, although many people try not to use the word "adaptation" in this
context much any more simply to reduce confusion. If the word is used at all in physiology, it's now
commonly used as the phrase, "ontogenetic adaptation." The more common term for this phenomenon
nowadays is "habituation," which is defined to be an actively mediated feedback process of quelling
the response to a common stimulus. This definition is offered to make it distinct from a more simple
sensory fatigue response -- which will always occur if stimulation goes on long enough..

Wirt Atmar

In message <[email hidden]>, TomHendricks474 <[email hidden]> writes

[Nine Stones]

Quoted message said:

<< Yes, very perceptive of you. If we replace the word adaptation with exploitation then it may
provide a better understanding of the past 4.5 billion years.

The Universe is a cruel host.

[T.H.]

I don't think that is accurate - at least half of all aspects of life are symbiotic which includes
any cell with mitochondria, or chloroplasts or any multicell being. Bacteria that can use nitrogen
promote all life indirectly as do photosynthesizers. Also all social behavior etc. This dog eat dog
view of life is mostly a male opinion and in my 4 options is definetly option 2 - or in psychology -
look at the work of K. Horney and look at her description of the disorder she labels as "Moves
Against Others"

IMO we are anthropomorphing biology when we claim it is all violent conflict. And more importantly
it just isn't true.

[Nine Stones]

Every point you illustrated is an example of exploitation. The cells don't really care whether they
survive or not. It's just that the ones with the machinery which makes them survive, will survive,
until they are wiped out or a better bit of machinery comes along.
--
The Evolution earthpoetry.demon.co.ukearthpoetry.demon.co.ukOpen ↗ RC

"Wirt Atmar" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

R. Norman answers John Sutherland's question:

<snip>

Quoted message said:

Quoted message said:

There is physiological adaptation to environmental circumstances that occurs on the time scale of
seconds or minutes to days and months. There is evolutionary adaptation that occurs over
generations and is expressed as changes in the genetic information.

That's certainly true enough, although many people try not to use the word "adaptation" in this
context much any more simply to reduce confusion. If

the

Quoted message said:

word is used at all in physiology, it's now commonly used as the phrase, "ontogenetic adaptation."
The more common term for this phenomenon

nowadays is

Quoted message said:

"habituation," which is defined to be an actively mediated feedback

process of

Quoted message said:

quelling the response to a common stimulus. This definition is offered to

make

Quoted message said:

it distinct from a more simple sensory fatigue response -- which will

always

Quoted message said:

occur if stimulation goes on long enough..

That is right. So my comment is just this: Habituation is typically described as something like:
active inhibition of relatively irrelevant responses to relatively unimportant stimuli. (Or IOW a
ditto dampening-down or "selective Hibernation", only somewhat metaphorically so put, of sensory-
motivational brain states that representations of ditto aspects of the overall situation that an
indivudual happens to be in.)

It is a very popular and happily dealt with function.;-)

However what is less easy to intellectually integrate than the concept of "habituation" is those
aspects and occassions of life and living when the the irrelevant stimulation tends towards becoming
(or *is* - if allowed to be processed to a conscious extent) unbearably painful. The label most
commonly used to cover this last kind of inhibitory function is (I believe) "repression".

I have a settled for that it is best to view habituation as important and crucial, and repression as
even more crucially important versions of the same function.

P

<< Every point you illustrated is an example of exploitation. The cells don't really care whether
they survive or not. It's just that the ones with the machinery which makes them survive, will
survive, until they are wiped out or a better bit of machinery comes along.
--
The Evolution earthpoetry.demon.co.ukearthpoetry.demon.co.ukOpen ↗ RC

Quoted message said:

Quoted message said:

I'm sure you could say that about any altruistic behavior. But the point is that there is a
difference between conflict and symbiotic behavior. And to say all is conflict and nothing symbiotic
is half wrong at least IMO.

Just as men react to stress with fight and flight, and women react to stress with tend and befriend,
so there are two major options in relating to stress in nature - not one.

Also it is important to see that self preservation can easily lead to self and self's children
preservation, etc. So in a sense the most highly evolved symbiotic relationships go somewhat beyond
selfish behavior. And for that to happen there had to be the billions of years of symbiotic behavior
that came before in the history of life.

In message <[email hidden]>, TomHendricks474 <[email hidden]> writes

Quoted message said:

<< Every point you illustrated is an example of exploitation. The cells don't really care whether
they survive or not. It's just that the ones with the machinery which makes them survive, will
survive, until they are wiped out or a better bit of machinery comes along.

I'm sure you could say that about any altruistic behavior.

[NS]

Yes, that's why I wrote it.

But the point is that there is a difference between conflict and symbiotic behavior. And to say all
is conflict and nothing symbiotic is half wrong at least IMO.

[NS]

I didn't imply, all, is conflict. I implied that exploitation is across the board. The only reason
the cells in your heart care about the cells in your brain is because they help them survive and
vice versa.

Just as men react to stress with fight and flight, and women react to stress with tend and befriend,
so there are two major options in relating to stress in nature - not one.

[NS]

I don't agree with your characterisations, but this is a thread drift which I don't have time for.

Also it is important to see that self preservation can easily lead to self and self's children
preservation, etc.

[NS]

This all comes from exploitation.

So in a sense the most highly evolved symbiotic relationships go somewhat beyond selfish behavior.

[NS]

No they don't.

And for that to happen there had to be the billions of years of symbiotic behavior that came before
in the history of life.

[NS]

Yes, exploitation.
--
The DNA earthpoetry.demon.co.ukearthpoetry.demon.co.ukOpen ↗ RC