Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 86 (8950 total)
34 online now:
Diomedes, marc9000, Percy (Admin), RAZD, Theodoric, Thugpreacha (AdminPhat) (6 members, 28 visitors)
Newest Member: Mikee
Post Volume: Total: 867,191 Year: 22,227/19,786 Month: 790/1,834 Week: 290/500 Day: 53/65 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Is Reproductive Success the Gold Standard?
lyx2no
Member (Idle past 3058 days)
Posts: 1277
From: A vast, undifferentiated plane.
Joined: 02-28-2008


Message 16 of 20 (497690)
02-05-2009 3:35 PM
Reply to: Message 11 by RAZD
01-31-2009 8:42 PM


Not There Yet.
Sorry for my absence. I was on computer restriction.

And I'm sure she already knows. Maybe fonda her "Help, Help me Ronda" days ...

You clearly know nothing about my mum; she thinks your language was salacious. My mum denies that such a thing is possible before marriage, and being fictitious was not an excuse for Ronda’s boldness. Mum tells me I must select a girl from her village (outside Yala) in Ghana. Whee! I get to marry a cousin. I’m going to catch it for this.

That's where the beauty of combining it with the 98% similarity metric comes in. For instance, we can look at the fossil record of Pelycodus:

I’m not sure what “it” is, yet. “It” refers back to this entire:

quote:
Phylogenetic (Cladistic)/ Evolutionary / Darwinian species

A group of organisms that shares an ancestor; a lineage that maintains its integrity with respect to other lineages through both time and space. At some point in the progress of such a group, members may diverge from one another: when such a divergence becomes sufficiently clear, the two populations are regarded as separate species. Subspecies as such are not recognized under this approach; either a population is a phylogenetic species or it is not taxonomically distinguishable.


But what does “when such a divergence becomes sufficiently clear” mean? How is “sufficient difference” determined? What do the little, black, horizontal bars in the image represent? Who is John Galt?

How does one calculate the 98% similarity with an extinct species? I’m assuming, here, that one looks at some portion of a gene and counts the differences, subtracts them from the portion then divides that buy the portion. So if we don’t have some portion of the genome… what? Are they comparing the ratios of all those little measurements they seem to be continually making with their calipers instead?

I’d be more then happy to read up on it at another site if you’d point the way. I wouldn’t want to take up so much of your time.

Edited by lyx2no, : Referring to my mum as she three times — opps!


Genesis 2
17 But of the ponderosa pine, thou shalt not eat of it; for in the day that thou shinniest thereof thou shalt sorely learn of thy nakedness.
18 And we all live happily ever after.

This message is a reply to:
 Message 11 by RAZD, posted 01-31-2009 8:42 PM RAZD has responded

Replies to this message:
 Message 17 by RAZD, posted 02-05-2009 10:17 PM lyx2no has responded

  
RAZD
Member
Posts: 20329
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.6


Message 17 of 20 (497739)
02-05-2009 10:17 PM
Reply to: Message 16 by lyx2no
02-05-2009 3:35 PM


Re: Not There Yet.
Hey lyx2no2,

Whee! I get to marry a cousin.

There's a series of jokes that all have the pattern "you may be a redneck if ..." (the term "redneck" implying ignorant country bumpkin with sunburned neck from long hours of hard field work), and one of my favorites is "you may be a redneck if you get married for the third time and still have the same in-laws"...

I’m not sure what “it” is, yet. “It” refers back to this entire:

"IT" is the division of a parent population into separate daughter populations that are no longer sharing genetic material by breeding.\

The question is whether reproductive separation is sufficient to declare speciation. So the idea is to compare the degree of similarity between the two branches to see if there is sufficient divergence to match the assumed level for arbitrary speciation. You have the same amount of difference, but in space instead of time.

But what does “when such a divergence becomes sufficiently clear” mean? How is “sufficient difference” determined? What do the little, black, horizontal bars in the image represent? Who is John Galt?

John Galt had the opportunity to drink perfect coffee.

The black horizontal bars represent the variation in the population at each specific level, with thicker bars for more numbers in that size - like a normal distribution of variation of a trait in any population.

How does one calculate the 98% similarity with an extinct species? I’m assuming, here, that one looks at some portion of a gene ...

That's why I prefer "traits" to "genes" - traits are seen in the visible parts of the fossils, the result of gene expression, rather than the gene itself. This is also more important for evolution, as evolution is based on selection of the phenotype - the expressed genes combined with the development of the organism.

When comparing fossil skeletons you can compare proportions of bones, size, distribution, etc. without needing to refer to the actual genes that led to such differences.

Are they comparing the ratios of all those little measurements they seem to be continually making with their calipers instead?

Yes, indeed. Well done. A little known aspect of paleontology is the exhaustive comparative anatomy that goes into cataloging species, variations in the species and why scientists feel they have found a "new" species.

Yes a lot of it is subjective, but the issue is consistency. Some people are "lumpers" - grouping a lot of variation into a small set of species - while others are "splitters" - dividing the variations into lots of species. Lumpers and splitters are each internally consistent, so they end up with the same overall pattern, just with a different number of nodes along the way.

Enjoy


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 16 by lyx2no, posted 02-05-2009 3:35 PM lyx2no has responded

Replies to this message:
 Message 18 by lyx2no, posted 02-05-2009 11:06 PM RAZD has responded

  
lyx2no
Member (Idle past 3058 days)
Posts: 1277
From: A vast, undifferentiated plane.
Joined: 02-28-2008


Message 18 of 20 (497744)
02-05-2009 11:06 PM
Reply to: Message 17 by RAZD
02-05-2009 10:17 PM


There
Thank you. That was very good.

Yes a lot of it is subjective, but the issue is consistency. Some people are "lumpers" - grouping a lot of variation into a small set of species - while others are "splitters" - dividing the variations into lots of species. Lumpers and splitters are each internally consistent, so they end up with the same overall pattern, just with a different number of nodes along the way.

I remember Gould writing something (Panda's Thumb?) along these line about snails, which I believe he worked with.


Genesis 2
17 But of the ponderosa pine, thou shalt not eat of it; for in the day that thou shinniest thereof thou shalt sorely learn of thy nakedness.
18 And we all live happily ever after.

This message is a reply to:
 Message 17 by RAZD, posted 02-05-2009 10:17 PM RAZD has responded

Replies to this message:
 Message 19 by RAZD, posted 02-09-2009 8:29 PM lyx2no has not yet responded

  
RAZD
Member
Posts: 20329
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.6


Message 19 of 20 (498345)
02-09-2009 8:29 PM
Reply to: Message 18 by lyx2no
02-05-2009 11:06 PM


Re: There
Yep.

... about snails, which I believe he worked with.

Extensively, this article shows evolution at a snails pace:
http://www.hno.harvard.edu/gazette/1997/01.09/SnailsCaughtinA.html

Enjoy


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 18 by lyx2no, posted 02-05-2009 11:06 PM lyx2no has not yet responded

Replies to this message:
 Message 20 by olivortex, posted 02-19-2009 12:07 PM RAZD has acknowledged this reply

  
olivortex
Member (Idle past 3120 days)
Posts: 70
From: versailles, france
Joined: 01-28-2009


Message 20 of 20 (499609)
02-19-2009 12:07 PM
Reply to: Message 19 by RAZD
02-09-2009 8:29 PM


Re: There
Extensively, this article shows evolution at a snails pace:
http://www.hno.harvard.edu/gazette/1997/01.09/SnailsCaughtinA.html

Thank you RAZD. Observation is the key and has always been. Too bad not everybody agrees on the concept of observation...

"Everybody believes in something and everybody, by virtue of the fact that they believe in something, uses that something to support their own existence." Frank Zappa.


This message is a reply to:
 Message 19 by RAZD, posted 02-09-2009 8:29 PM RAZD has acknowledged this reply

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019