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Author Topic:   An ongoing report on S366:Evolution
pandion
Member (Idle past 1077 days)
Posts: 166
From: Houston
Joined: 04-06-2009


Message 16 of 29 (542049)
01-07-2010 11:18 AM


Futuyma defines evolution
In my old text by Futuyma, Evolutionary Biology, 2nd Ed., he gets right down to the definition of biological evolution on the second page of chapter 1. Futuyma says:
quote:
Thus biological (or organic) evolution is change in the properties of populations of organisms, or groups of such populations, over the course of generations.

Futuyma had previously explained that the properties about which he is speaking are are those "...in which there is hereditary transmission of characteristics, variation owing to mutation, and sorting of variation by several processes." To be a bit more terse, I learned many years ago that evolution is a change in allele frequencies in populations of organisms over generations.

Don't confuse this with theories of evolution. The above is not a theory. It is a definition that was arrived at during the formulation of the modern synthesis. Theories of evolution are explanations of observed phenomena that fit the above definition. For example, observed change without heredity is not evolution.

As for Punk Eek, I'm sure Futuyma will get to it. But PE isn't a theory about the how of evolution like natural selection, genetic drift, gene flow, mutation, non-random mating, recombination, movable elements, or biased variation. Those are theories that offer explanations about the very nature of evolution, about increases and decreases in genetic variability, all of which Futuyma will probably cover in your text (he did in mine in 1998). I think that he will also discuss the defunct theories of saltationism, and the opposite view of gradualism. And he will get to Punk Eek. All of these theories are not about the nature of evolution, but rather the pace of evolution.

By the way, I bought and read Evolutionary Biology many years after I had completed my education (but not my studies). You see, Futuyma hadn't written any books when I was in school. I'm just a bit older than he.

Get ready for the math. That was one of the things that caused me the most trouble and delay. I had to depend on my children to help me (one a nuclear engineer the other math major) get through that. The study of biology involves a lot more math today than it did in my day.


Replies to this message:
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Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 17 of 29 (542054)
01-07-2010 11:49 AM
Reply to: Message 16 by pandion
01-07-2010 11:18 AM


Re: Futuyma defines evolution
Yeah, I've read Evolutionary Biology too, and Futuyma repeats the definition you give in Evolution.
This message is a reply to:
 Message 16 by pandion, posted 01-07-2010 11:18 AM pandion has not yet responded

  
Peepul
Member (Idle past 3095 days)
Posts: 206
Joined: 03-13-2009


(1)
Message 18 of 29 (542064)
01-07-2010 12:57 PM
Reply to: Message 15 by Dr Jack
01-07-2010 4:37 AM


Re: Section A: Evolutionary Biology
Kaichos Man,

A Happy New Year to you too.

quote:
Punc eq is such an opportunistic painted harlot of a theory that you generally have to bang on and on about the lack of transitionals in the fossil record to force it out of the cupboard.

Creationists generally misunderstand what Gould was trying to say (you may not fall into that category of course).

The lack of transitionals that Gould was talking about was small-scale, ie between what would be considered very similar species, neighbours on the tree of life. Creationists these days accept that this kind of evolution occurs, in fact they are vastly over-optimistic about what it can achieve in 6000 years.

Creationists generally mean by lack of transitionals a lack of transitionals between major groups, and they often quote Gould in support of that view.

But it's not what he meant.

Since we proposed punctuated equilibria to explain trends, it is infuriating to be quoted again and again by creationists -- whether through design or stupidity, I do not know -- as admitting that the fossil record includes no transitional forms. Transitional forms are generally lacking at the species level, but they are abundant between larger groups.

Gould, Stephen Jay 1983. "Evolution as Fact and Theory" in Hens Teeth and Horse's Toes: Further Reflections in Natural History. New York: W. W. Norton & Co., p. 258-260.

If this is not news to you, then there's always a chance it may be news to somebody else... There is no justification for using Gould to criticise macroevolution.

I'm probably off topic and will now shut up.

Edited by Peepul, : No reason given.

Edited by Peepul, : No reason given.


This message is a reply to:
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Replies to this message:
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Kaichos Man
Member (Idle past 2565 days)
Posts: 250
From: Tasmania, Australia
Joined: 10-03-2009


Message 19 of 29 (542416)
01-09-2010 10:11 PM
Reply to: Message 18 by Peepul
01-07-2010 12:57 PM


Re: Section A: Evolutionary Biology
The lack of transitionals that Gould was talking about was small-scale, ie between what would be considered very similar species, neighbours on the tree of life.

And this is prcisely what we should see in the fossil record in abundance. Darwin was certain that future fossil finds would support his theory. They didn't. So now neo-Darwinists harp on about fossils being "extremely rare", and "difficult to form".

What a load of parrot droppings. Take a look around. Rivers, lakes, seas and oceans everywhere. Daily tides. Frequent droughts and floods. Fossils are being formed by the ton as we speak, all over the world. And this process has been going on for (supposedly) millions of years. If the theory of evolution was true, we would be up to our necks in transitional fossils, each tiny darwinian step lovingly catalogued in the strata.

The lack of transitional fossils can only -only- be explained by a lack of transitional species.

Creationists these days accept that this kind of evolution occurs

Only if it's sideways or downwards in genetic complexity. Stochastic processes can't create new genes without overcoming prohibitive odds.

in fact they are vastly over-optimistic about what it can achieve in 6000 years.

Not really. The British mosquito has speciated in just 100 years.

Transitional forms are generally lacking at the species level, but they are abundant between larger groups.

No they are not. They are rare, often fragmentary and always hotly disputed (and not just by Creationists, I should add).

There is no justification for using Gould to criticise macroevolution.

Try telling that to Dickie Dawkins.


"Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
This message is a reply to:
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RAZD
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Posts: 19756
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Message 20 of 29 (542418)
01-09-2010 10:47 PM
Reply to: Message 19 by Kaichos Man
01-09-2010 10:11 PM


off topic rambling refuted
Hi Kaichos Man, trying to spread denial to a new thread to drag it off topic?

The lack of transitional fossils can only -only- be explained by a lack of transitional species.

Ah yes, the "absence of evidence is evidence of absence" logical fallacy. Congratulations for being so clearly wrong.

The complete absence of fossil evidence for the Coelacanth since the end of the Cretaceous period clearly proves that these did not exist between then and now.

Then there is the matter of foramiinifera:

Evolution at Sea
Complete Fossil Record from the Ocean Upholds Darwins Gradualism

quote:
Tony Arnold and Bill Parker compiled what may be the largest, most complete set of data on the evolutionary history of any group of organisms, marine or otherwise. The two scientists amassed something that their land-based colleagues only dreamed about: An intact fossil record with no missing links.

"It's all here--a virtually complete evolutionary record," says Arnold. "There are other good examples, but this is by far the best. We're seeing the whole picture of how this group of organisms has changed throughout most of its existence on Earth."

The organism that Arnold and Parker study is a single-celled, microscopic animal belonging to the Foraminiferida, an order of hard-shelled, planktonic marine protozoans. Often shortened to "forams," the name comes from the Latin word foramen, or "opening." The organisms can be likened to amoebas wearing shells, with perforations through which their protoplasm extends. The foram shell shapes range from plain to bizarre.
...
"There's a nifty passage in Darwin," says Arnold, "in which he descirbes the fossil record as a library with only a few books, and each book has only a few chapters. The chapters have only a few words, and the words are missing letters."

"Well, in this case, we've got a relatively complete library," says Arnold. "The 'books' are in excellent shape. You can see every page, every word."

As he speaks, Arnold shows a series of microphotographs, depicting the evolutionary change wrought on a single foram species. "This is the same organism, as it existed through 500,000 years," he says. "We've got hundreds of examples like this, complete life and evolutionary histories for dozens of species."

About 330 species of living and extinct planktonic forams have been classified so far. After thorough examinations of marine sediments collected from around the world, micropaleontologists now suspect these are just about all the free-floating forams that ever existed.

The species collection also is exceptionally well-preserved, which accounts largely for the excitement shared by Parker and Arnold. "Most fossils, particularly those of the vertebrates, are fragmented--just odds and ends," says Parker. "But these fossils are almost perfectly preserved, despite being millions of years old."
...
Darwin termed the process gradualism, a theory that invokes the slow accumulation of small evolutionary changes over a large period of time, as a result of the pressures of natural selection. What Arnold and Parker found is almost a textbook example of gradualism at work.

We've literally seen hundreds of speciation events," syas Arnold. "This allows us to check for patterns, to determine what exactly is going on. We can quickly tell whether something is a recurring phenomenon--a pattern--or whether it's just an anomally. This way, we cannot only look for the same things that have been observed in living organisms, but we can see just how often these things really happen in the environment over an enormous period of time.


Not just transitional fossils between one species to the next, but the whole pattern of this particular phylum laid out in detail.

What a load of parrot droppings. Take a look around. Rivers, lakes, seas and oceans everywhere. Daily tides. Frequent droughts and floods. Fossils are being formed by the ton as we speak, all over the world. And this process has been going on for (supposedly) millions of years. If the theory of evolution was true, we would be up to our necks in transitional fossils, each tiny darwinian step lovingly catalogued in the strata.

As we see in the case of foraminifera, transitional fossils between species (and higher) exist, and in this one case it covers millions of years in a continuous record where the accumulation of fossils is not reliant on environmental or other factors. Thus we see, that when there are no causes preventing the reservation of fossils, or for disrupting fossils after deposition, that there is indeed the preserved record of evolving life year after year, generation after generation, species after species, for millions of years.

Your opinion has once again been invalidated by fact. Watch out for those parrot droppings.

btw - you are off topic here, so I suggest you do not reply but start another thread.

Now we return to our regular programing: "An ongoing report on S366:Evolution" - of interest? by Mr Jack

... an ongoing report of what I'm studying on the course ... As a case study in what real Evolutionary biology (even if only at undergraduate level) covers?

Post moved to new topic to remove off-topic material
see Transitional Fossils Show Evolution in Process

Enjoy.

Edited by RAZD, : coelacanth added

Edited by RAZD, : off topic

Edited by RAZD, : ...

Edited by RAZD, : .

Edited by RAZD, : ..

Edited by RAZD, : moved post to new topic

Edited by RAZD, : link updated


This message is a reply to:
 Message 19 by Kaichos Man, posted 01-09-2010 10:11 PM Kaichos Man has not yet responded

  
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Message 21 of 29 (542462)
01-10-2010 7:37 AM


Topic Reminder
Hi everyone!

This thread is intended as a presentation of the material in a course on evolution in order to get a clear idea of what is typically covered in such courses these days. If you disagree with the material then propose a new thread to discuss that, but do not discuss it here in this thread.

If you posted a message after this one that violated this request but before seeing this message then fix it quick before I see it.


--Percy
EvC Forum Director

    
Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 22 of 29 (543005)
01-14-2010 2:18 PM


Section B: Adaptation
Here, the OU course diverges from the pattern of Futuyma text book and gives a short introduction to the concept of adaptation which is not mentioned until later by Futuyma. Adaptation is not given a clear definition, but instead we're introduced to a case study looking at variation in reindeer subspecies and, especially, the difference between Svalbard and Norwegian reindeer. The text is backed by a half hour video. Issues discussed include herding behaviour, athletic ability, differences in digestion and fat storage, and modifications to the shape of the head.

Also introduced is the concept of vestigial features, both physiological and behavioural, which are defined as "features, structures, biochemical pathways or behaviour[s] [which] are not currently adaptive ... although they may facilitate embryonic development". Examples are given of the canine teeth in reindeer which have only studs which do not even break the skin, and of stotting behaviour in Svalbard reindeer.

Again, this is fairly introductory stuff, although some of the discussion of the benefits and trade of adaptive behaviours was quite detailed, nothing quantative was mentioned and there was no mention of genetics or any of the 'how' of adaptation. I'm presuming this will be covered later when we get to the section where Futuyma deals with it.

Edited by Mr Jack, : Missed a closing "


Replies to this message:
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Wounded King
Member (Idle past 2172 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 23 of 29 (543077)
01-15-2010 8:19 AM
Reply to: Message 22 by Dr Jack
01-14-2010 2:18 PM


Re: Section B: Adaptation
oops. Missed Percy's message above.
WK

Edited by Wounded King, : No reason given.


This message is a reply to:
 Message 22 by Dr Jack, posted 01-14-2010 2:18 PM Dr Jack has acknowledged this reply

    
Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 24 of 29 (546648)
02-12-2010 11:42 AM


A note on timing
I should perhaps point out that the course didn't officially start until this week, I just got an early start on some of it while I had a bit of free time. Being an OU course, progress will tend to vary like that. Also, the sections are not of equal length so expect a little variety on when the next updates arrive.
  
Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 25 of 29 (547662)
02-21-2010 10:18 AM


Section C: Classification and phylogeny
Section C is based around Futuyma chapter 2, although large sections of the text are replaced with an interactive computer exercise on manually creating phylogenic trees.

This section started with a discussion of different classification systems, and what it means for a system to be a "natural classification". The concepts of a clades, mono-/para-/poly-phyletic groups and parsimony are introduced and the meaning of characters and character states. Then the means of generating phylogenetic trees from character data, or genetic data, are discussed. Initially, simple clear cut examples are considered but the course rapidly moves on to discussing the many problems of correctly deducing trees from the data and the various means by which the resulting trees can be scored and assessed.

Finally, we were introduced to some software for generating the trees from phylogenic data: PARSimony, part of the PHYLIP package.


  
Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 26 of 29 (549731)
03-10-2010 9:03 AM


Section D: Patterns of Evolution
This section is based around chapter 3 of Futuyma. The comments, interestingly for those who claim macroevolution is not a term used by scientists begin "[Futuyma] Chapter 3 discusses macroevolutionary patterns".

The section begins with an overview of evolutionary history and classification - no surprises here for anyone with a passing familiarity with modern evolutionary thought - brushes over mono, para and poly phyletic groups and then moves on to more in-depth material. First up is a discussion of the many forms of homoplasy* that occur and muddy the elucidation of phylogeny. It makes the salient point that a feature can be both homologous** and homoplasious, for example the wings of bats, birds and pterosaurs are homologous if considered as vertebrate forelimbs but homoplasious as wing structures. The biggest part of the section though concentrates on patterns in how characters change: individualisation (when previously uniform features such as leaves or legs differentiate), heterochrony (when changes in timing and rate of development produces different features) and heterotopy (when features become expressed in different parts of the body) are discussed but the biggest part of the section (including a lot of material in the course book) looks at allometry which is where different features of an organism grow at different rates.

Finally, this section looks at adaptive radiation (described by Futuyma as the most common long term feature of evolutionary lineages) and finishes with a video investigating adaptive radiation in horses.

* - homoplasy = features of similar form/function not arising from common ancestry.
** - homology = features of similar form/function arising from common ancestry.

Edited by Mr Jack, : Garbled the title


  
Dr Jack
Member (Idle past 182 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


(1)
Message 27 of 29 (587625)
10-19-2010 7:15 PM


Fail
So, er, I completely failed to keep up with this, many apologies, I took my exam for this course last week and my final exam today. I will endeavour to give a synopsis on it all in the next few days.
Replies to this message:
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olivortex
Member (Idle past 2855 days)
Posts: 70
From: versailles, france
Joined: 01-28-2009


Message 28 of 29 (587867)
10-21-2010 6:31 AM
Reply to: Message 27 by Dr Jack
10-19-2010 7:15 PM


Re: Fail
I'm interested too! Don't worry about how late you'll post the stuff.
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onlinekk 
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Message 29 of 29 (588776)
10-28-2010 8:52 AM


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