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Author Topic:   What is a theory in biology?
ProfessorR
Inactive Member


Message 1 of 22 (204612)
05-03-2005 10:20 AM


Dear group,
Recently, I had an exchange with a member of this forum who, discussing intelligent design, said that there is no such thing as the theory of evolution. If I understand him correctly, he thinks that biologists, as opposed to other scientists (e.g., physcists) lack some essential elements of training in scientific method and, therefore, misunderstand the term "theory."
In this regard, may I ask, what really is a theory in biology?
Here is my thought on it (please note that I am a researcher-experimenter and, more recently, a university biology teacher but not an expert-professional in the scientific method, philosophy of science etc.). I understand theory in biology as an unusually interesting and daring hypothesis with a broad scope and interest to all biologists, regardless of their narrow field of study. Like any hypothesis, a theory is a human statement (or a set of statements) that is, essentially, a "guess" trying to explain certain natural phenomena. However, UNLIKE most hypotheses, a theory is a statement or a set of statements that provides an explanatory framework to *life* in general (while most hypotheses in biology are guesses trying to explain only certain manifestations of life).
If this understanding of a theory is anywhere near truth, then the theory of biological evolution - which, essentially, states that life as we know it is being constantly diversified because of the constant action of factors like mutation, natural selection, genetic drift, gene flow, and other suchlike factors - is, actually, a true theory. So are such theory as the chromosomal theory of heredity or the cellular theory. On the other hand, hypotheses that are concerned with particular manifestations of life are not theories, even if they are extremely interesting and daring; for example, Burnet's hypothesis of clonal selection or Jerne's network hypothesis are not theories, because they do not address phenomena outside of just one manifestation of life (the ability of some life forms to mount immune responses).
I will be very grateful for all your insights.
Best wishes,
Richard

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 Message 3 by mick, posted 05-03-2005 12:29 PM ProfessorR has replied

  
AdminNosy
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Posts: 4754
From: Vancouver, BC, Canada
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Message 2 of 22 (204626)
05-03-2005 11:08 AM


Thread moved here from the Proposed New Topics forum.

  
mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 3 of 22 (204661)
05-03-2005 12:29 PM
Reply to: Message 1 by ProfessorR
05-03-2005 10:20 AM


Some decent definitions might help. Here are some quotes from the Oxford English Dictionary, which also provides relevant quotations showing usage.
OED writes:
HYPOTHESIS
1. A subordinate particular thesis involved in a general thesis; a particular case of a general proposition. In quot. 1596, a particular or detailed statement. Cf. F. hypothse (sense 3 in Littr). Obs.

1596 EARL OF ESSEX in Ellis Orig. Lett. Ser. III. IV. 137 If I be commaunded to sett doune the Hypothesis, or to descend into particulars. 1620 T. GRANGER Div. Logike 10 note, The compound Theme is also (a) speciall, or (b) generall: (a) Hypothesis; (b) Thesis. Ibid. 204 To amplifie a speciall or particular sentence, called hypothesis. 1638 BAKER tr. Balzac's Lett. (Vol. III.) 24 Without descending from the thesis to the hypothesis. a1647 FILMER Patriarcha i. 1 (1884) 13 If the thesis be true, the hypothesis will follow. a1721 J. KEILL Maupertius' Diss. (1734) 49 Whence it is plain that there is no Hypothesis wherein the Spheroid is not flat at the Poles.
b. A proposition laid down; a thesis. Obs.

1669 GALE Crt. Gentiles I. Introd. 1 Endeavoring to promote this Hypothesis. 1678 Ibid. III. Pref., It is..impossible..demonstratively to discusse such an hypothesis without some opposition against such as defend the antithesis.
2. A proposition or principle put forth or stated (without any reference to its correspondence with fact) merely as a basis for reasoning or argument, or as a premiss from which to draw a conclusion; a supposition. In Logic, the supposition or condition forming the antecedent or protasis of a conjunctive or conditional proposition (e.g. If A is B, C is D): cf. HYPOTHETICAL 1b.

1656 BLOUNT Glossogr., Hypothesis, a supposition or condition; sometimes it is taken for a Position of something, as it were demonstrated, and granted by another. 1657 J. SMITH Myst. Rhet. 263 Hypothesis is an argument or matter whereon one may dispute; or it is a conditional proposition. 1660 BARROW Euclid I. xxvii. (1714) 23 Which being supposed, the outward angle AEF will be greater than the inward angle DFE, to which it was equal by Hypothesis. 1827 HUTTON Course Math. I. 3 An Hypothesis is a supposition assumed to be true, in order to argue from, or to found upon it the reasoning and demonstration of some proposition. 1837 BABBAGE Bridgew. Treat. App. E. 196 Collusion being, by hypothesis, out of the question. 1885 C. LEUDESDORF Cremona's Proj. Geom. 67 The hypothesis is satisfied in the particular case where the rays a and a coincide.
b. An actual or possible condition or state of things considered or dealt with as a basis for action; one of several such possible conditions, a case or alternative (cf. 1).

1794 BURKE Corr. IV. 217 The other hypothesis, upon which the war ought ‘to be carried on with vigour’, though last put, must be preliminary to the other. 1803 WELLINGTON Let. to Col. Stevenson in Gurw. Desp. I. 545 In each of these last hypotheses, you will observe the necessity that we should be within reach of each other. 1876 MOZLEY Univ. Serm. v. 119 Christianity..only sanctions war..upon the hypothesis of a world at discord with herself.
3. A supposition or conjecture put forth to account for known facts; esp. in the sciences, a provisional supposition from which to draw conclusions that shall be in accordance with known facts, and which serves as a starting-point for further investigation by which it may be proved or disproved and the true theory arrived at.

1646 SIR T. BROWNE Pseud. Ep. II. ii. 60 Irons doe manifest a verticity not only upon refrigeration..but (what is wonderfull and advanceth the magneticall hypothesis) they evidence the same by meer position according as..their extreams [are] disposed..unto the earth. 1660 R. COKE Power & Subj. 265 By a perpetuall motion of the Earth from West to East according to the new Hypotheses in Astronomy, or of the Sun from East to West, after the former Hypotheses. 1664 POWER Exp. Philos. 82 To make good the Atomical Hypothesis. 1674 BOYLE Excell. Theol. I. v. 207 One of the conditions of a good hypothesis is, that it fairly comport..with all other phnomena of nature, as well as those 'tis framed to explicate. 1774 WARTON Hist. Eng. Poetry (1775) I. Diss. i. 22 A late ingenious critic has advanced an hypothesis, which assigns a new source, and a much earlier date, to these fictions. 1843 MILL Logic III. xiv. 4 It appears..to be a condition of a genuinely scientific hypothesis, that it be not destined always to remain an hypothesis, but be of such a nature as to be either proved or disproved by that comparison with observed facts which is termed Verification. 1862 HUXLEY Lect. Wrkg. Men 67 Do not allow yourselves to be misled by the common notion that a hypothesis is untrustworthy simply because it is a hypothesis. 1893 SIR R. BALL In High Heav. ix. 212 The celebrated nebular hypotheses of Herschel and of Laplace.
4. A supposition in general; something supposed or assumed to be true without proof or conclusive evidence; an assumption.

1654 H. L'ESTRANGE Chas. I (1655) 182 The Romanists..began..to cry him [Laud] up for their Proselyte. Upon this hypothesis..they grew excessive proud and insolent. 1665 SIR T. HERBERT Trav. (1677) 352 That no other place in the East-Indies produces Gold..An Hypothesis found mistaken by such as drive a Trade for Gold..towards Cochin-China. 1827 JARMAN Powell's Devises II. 353 The gift should first be read on the supposition that it is intended to embrace legitimate children, and if there be nothing in the terms..or..context, incompatible with this hypothesis [etc.]. 1868 GLADSTONE Juv. Mundi iii. (1870) 76 The hypothesis that the Pelasgians were the base of the Greek nation.
b. Hence spec. A groundless or insufficiently grounded supposition; a mere assumption or guess.

1625 N. CARPENTER Geog. Del. I. iv. (1635) 87 Which later Astronomers..haue derided, or at least omitted as Hypotheses or suppositions. 1747 WESLEY Prim. Physic (1762) p. ix, To build Physick upon Hypotheses. 1827 SCOTT Surg. Dau. vii, Your reasoning..seems plausible; but still it is only hypothesis. 1865 SEELEY Ecce Homo v. (ed. 8) 46 The statement rests on no hypothesis or conjecture; his [Paul's] Epistles bear testimony to it. 1876 E. MELLOR Priesth. i. 14 This explanation of Bellarmine..is a pure hypothesis, for which there is not a shadow of evidence in the New Testament itself.
Hence hypothesist, one who forms a hypothesis.

1788 T. JEFFERSON Writ. (1859) II. 431 The blank..must remain for some happier hypothesist to fill up.
OED writes:
THEORY
1. A sight, a spectacle. Obs. rare.

1605 BP. ANDREWES Serm., Passion (1631) 365 Saint Luke..calleth the Passion a Theory or Sight... Of our blessed Saviour's whole life or death, there is no part but is a Theorie of it selfe, well worthie our looking on.
2. Mental view, contemplation. Obs.

[1598-1611 FLORIO, Theora, contemplation, speculation, deepe study, insight or beholding.] 1611 COTGR., Theorie, theorie, contemplation, deepe studie; a sight, or beholding, speculation. 1643 SIR T. BROWNE Relig. Med. I. 45 Nor can I thinke I have the true Theory of death when I contemplate a skull, or behold a Skeleton with those vulgar imaginations it casts upon us. 1646 Pseud. Ep. VII. xix. 385 As they encrease the hatred of vice in some, so doe they enlarge the theory of wickednesse in all. 1653 W. HARVEY Anat. Exercit. Pref. v, All their theory and contemplation (which they count Science) represents nothing but waking mens dreams, and sick mens phrensies. 1710 NORRIS Chr. Prud. ii. 65 Speculative Knowledge contemplates Truth for itself, and accordingly stops and rests in the Contemplation of it, which is what we commonly call Theory.
3. A conception or mental scheme of something to be done, or of the method of doing it; a systematic statement of rules or principles to be followed.

1597 HOOKER Eccl. Pol. V. xxix. 8 If they had been themselves to execute their owne Theorie in this Church. 1643 BP. HALL Devout Soul i, It will hardly be believed, how far some of their contemplative men have gone in the theory hereof. 1674 DRYDEN Prol. Univ. Oxford 11 Your theories are here to practice brought, As in mechanic operations wrought. 1798 MALTHUS Popul. III. ii. (1806) II. 103 A theory that will not admit of application cannot possibly be just. 1832 AUSTIN Jurispr. (1879) II. 1133 Theory of what is and theory of what ought to be are perpetually confounded. 1853 BRIGHT Sp. India 3 June (1876) 4 The theory of the old Government of India was one which could not be defended. 1879 M. PATTISON Milton xiii. 219 Even the calm and gentle author of the Christian Year..deliberately framed a theory of Poetic for the express purpose, as it would seem, of excluding the author of Paradise Lost from the first class of poets.
4. a. A scheme or system of ideas or statements held as an explanation or account of a group of facts or phenomena; a hypothesis that has been confirmed or established by observation or experiment, and is propounded or accepted as accounting for the known facts; a statement of what are held to be the general laws, principles, or causes of something known or observed.

1638 SIR T. HERBERT Trav. (ed. 2) 127 Or whether from subterranean fires,..I dare not conclude, but leave such theories to those that study Meteors. 1684 BURNET (title) The Theory of the Earth. 1706 PHILLIPS (ed. Kersey), Theories of the Planets, certain Hypotheses, or Suppositions about the Motions of the Heavens, according to which, Astronomers explain..the Phnomena or Appearances of the Planets. 1727-41 CHAMBERS Cycl. s.v., We say..theory of the rainbow, of the microscope..the motion of the heart, the operation of purgatives, etc. 1812 PLAYFAIR Nat. Phil. (1819) I. 3 A theory is often nothing else but a contrivance for comprehending a certain number of facts under one expression. 1850 GROVE Corr. Phys. Forces (ed. 2) 105 Were a theory open to no objection it would cease to be a theory, and would become a law. 1879 M. PATTISON Milton xiii. 180 The Copernican theory, which placed the sun in the centre of our system, was already the established belief of the few well-informed. 1890 A. R. WALLACE Darwinism 7 The truest and most complete theory would not enable us to solve all the difficult problems which the whole course of the development of life upon our globe presents to us.
b. That department of an art or technical subject which consists in the knowledge or statement of the facts on which it depends, or of its principles or methods, as distinguished from the practice of it.

1613 R. CAWDREY Table Alph. (ed. 3), Theorie, the contemplation, or inward knowledge of any art. 1626 BACON Sylva 327 The means, hitherto propounded, to effect it, are in the practice, full of error and imposture, and in the theory, full of unsound imaginations. 1660 R. COKE Power & Subj. Pref. 5 A Musitian, who Composes well, yet under~stands but little in the theory of Musick. 1795 HUTTON Math. Dict. s.v., To be learned in an art, &c., the Theory is sufficient; to be a master of it, both the Theory and practice are requisite. 1827 WHATELY Logic (ed. 2) 205 Logic being concerned with the theory of Reasoning. 1828 J. S. MILL in Westm. Rev. IX. 155 A prodigious step in the theory of naming. a1854 Early Draft Autobiogr. (1961) 135, I pushed on..to try whether I could do anything further to clear up the theory of Logic generally. 1884 GROVE Dict. Mus. IV. 101/1 Theory, a term often used..to express the knowledge of Harmony, Counter-point, Thorough~bass, etc., as distinguished from the art of playing, which is..called ‘Practice’. 1885 Encycl. Brit. XVIII. 793/2 Epistemology (theory of knowledge, Erkenntnisstheorie). 1927 B. RUSSELL Outl. Philos. xxiii. 248 Descartes..inaugurated two movements, one in metaphysics, one in theory of knowledge. 1966 R. M. CHISHOLM (title) Theory of Knowledge.
c. A systematic statement of the general principles or laws of some branch of mathematics; a set of theorems forming a connected system: as the theory of equations, of functions, of numbers, of probabilities.

1799 W. FREND (title) The Principles of Algebra..; or the true Theory of Equations established by mathematical demonstration. 1806 [see THEOREM 1a]. 1811 P. BARLOW (title) An Elementary Investigation of the Theory of Numbers. 1838 [see PROBABILITY 3]. 1893 FORSYTH (title) Theory of Functions.
5. In the abstract (without article): Systematic conception or statement of the principles of something; abstract knowledge, or the formulation of it: often used as implying more or less unsupported hypothesis (cf. 6): distinguished from or opposed to practice (cf. 4b). in theory (formerly in the theory): according to theory, theoretically (opp. to in practice or in fact).

1624 T. MACARNESSE in Capt. Smith Virginia Pref., That thou mightst read and know and safely see, What he by practice, thou by Theoree. 1692 SIR W. HOPE Fencing-Master (ed. 2) 164 Theorie without Practice will serve but for little. 1769-72 Junius Lett. Pref. (1820) 17 Theory is at variance with practise. 1776 J. ADAMS Wks. (1854) IX. 375 It is certain, in theory, that the only moral foundation of government is, the consent of the people. 1821 J. Q. ADAMS in Davies Metr. Syst. III. (1871) 175 A compromise between philosophical theory and inveterate popular habits.
6. In loose or general sense: A hypothesis proposed as an explanation; hence, a mere hypothesis, speculation, conjecture; an idea or set of ideas about something; an individual view or notion. Cf. 4.

1792 BURKE Corr. (1844) IV. 13 Whether I am right in the theory or not,..the fact is as I state it. 1794 PALEY Evid. (1825) II. 347 Theories which have, at different times, gained possession of the public mind. 1829 JAS. MILL Hum. Mind (1869) II. xxv. 403 The word theory has been perverted to denote an operation..which..consists in supposing and setting down matters supposed as matters observed. Theory in fact has been confounded with Hypothesis. 1864 BOWEN Logic xi. (1870) 375 A Theory, sometimes incorrectly used as a synonyme for Hypothesis. 1867 M. E. HERBERT Cradle L. iii. 95 So varied are the theories as to the origin of these wonderful sepulchres. 1880 T. A. SPALDING Eliz. Demonol. 35 This was not a mere theory, but a vital active belief.
7. Comb., as theory-making adj. and n., -building, -monger, -spinning; theory-bigoted, -mad, -ridden adjs.; theory-blind a., (a) blinded by a theory, so as to be unable to see the facts truly; (b) blind to a theory, i.e. unable to see or apprehend it (cf. colour-blind); theory-laden a., applied to a term, statement, etc., the use of which implies the acceptance of some theory; contrasted with theory-free, -neutral adjs.; theory-man (nonce-wd.), a theorist; theory-tailor, contemptuously for a shaper of theories.

1884 Q. Rev. Apr. 337 More *theory-bigoted than Mr. .
So I would agree with you.
I have always thought of a hypothesis as a prediction that can be tested. A theory, on the other hand, is what allows us to generate hypotheses. The theory is a formal systematic assemblage of knowledge (that is, hypotheses which have not been disproven, plus all the data we have gathered).
The theory of evolution is our general understanding of how the biological world works. We use the theory of evolution to generate hypotheses related to some specific system we are studying. If our hypotheses are supported by experiment, then they are incorporated into the theory. If not, then the theory might need to be modified.
the only reason this is confusing is that people, both within science and outside it, often use "theory" when they mean "hypothesis".
For example I might say:
I know that my girlfriend is a pretty devious kind of person. I have a theory that she is cheating on me with Frank. I'm going to have her followed by a private detective. If he shows that she isn't cheating on me, I guess my theory was wrong. But I still know that she's a devious kind of person.
What I really ought to say is:
Based on an accumulation of evidence, and previous hypotheses concerning my girlfriend's character that are supported by that evidence, I have a theory that she is a devious kind of person. I hypothesise that she is cheating on me with Frank. I'm going to test the hypothesis by having her followed by a private detective. If he finds that she isn't cheating on me, I guess that my hypothesis was wrong. I have enough evidence to maintain my theory that she is a devious person, but unfortunately my theory doesn't give me very good hypotheses.
This message has been edited by mick, 05-03-2005 12:31 PM
This message has been edited by mick, 05-03-2005 12:39 PM

This message is a reply to:
 Message 1 by ProfessorR, posted 05-03-2005 10:20 AM ProfessorR has replied

Replies to this message:
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ProfessorR
Inactive Member


Message 4 of 22 (204736)
05-03-2005 5:46 PM
Reply to: Message 3 by mick
05-03-2005 12:29 PM


Mick, thank you for your excellent comment. I did not know that the use of words "hypothesis" and "theory" has such a long history an that these terms were sometimes used in a context and with meaning very different from the currently conventional.
Also, I think it's an exellent point that a theory differs from a hypothesis in that a theory can by itself generate new hypotheses, while a hypothesis can only be tested.
Would you care to comment on the statement that "Darwinism" (or the modern theory of evolution) is not a scientific theory? What, in your opinion, makes people issue such a statement?
Thanks a lot again, and my best wishes,
Richard

This message is a reply to:
 Message 3 by mick, posted 05-03-2005 12:29 PM mick has replied

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 5 of 22 (204744)
05-03-2005 6:31 PM
Reply to: Message 4 by ProfessorR
05-03-2005 5:46 PM


Hi Richard,
Thanks, glad the OED was useful!
Would you care to comment on the statement that "Darwinism" (or the modern theory of evolution) is not a scientific theory? What, in your opinion, makes people issue such a statement?
Scientists who say this are probably afraid of the popular conception of "theory", which is taken to mean a kind of intellectual "stab in the dark". Scientists are afraid that if they use the word "theory" it will be misinterpreted by the public, and by other scientists. And to be honest, they are probably right.
It's also difficult to explain what a theory is, and what it is not, in a climate where we have stickers on textbooks saying "evolution is just a theory, not a fact", and these stickers are meant in a negative sense. Our local politicans and media, for example, does not want to spend their time on arcane matters, like what Sir Thomas Browne said about hypotheses in 1646!
For example consider the Cobb County textbook sticker
As a scientist, I don't disagree with that sticker whatsoever! But it's been said by my enemies, so I have to argue with them.

This message is a reply to:
 Message 4 by ProfessorR, posted 05-03-2005 5:46 PM ProfessorR has replied

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ProfessorR
Inactive Member


Message 6 of 22 (204748)
05-03-2005 6:50 PM
Reply to: Message 5 by mick
05-03-2005 6:31 PM


Mick, thanks again. Actually, I think evolution can be viewed as a fact (or as an observation). If we define biological evolution as a change in the genetic makeup of populations, than it IS a fact, or, if you will, such change HAS been directly observed. On the other hand, there is something that I believe to be a scientific theory, called "the theory of evolution." It states that life has been diversified and continues to be diversified due to evolution (see the definition of evolution above).
Another question. What if we ask authors of those infamous textbook stickers - just why do you guys concentrate on evolution? Let chemistry textbooks contain stickers that say, "atoms and molecules are a theory, not a fact" (indeed, who saw them?). Let physics textbooks have stickers that say, "Electromagnetic field is a theory, not a fact," etc. etc. etc. Why evolution?
Richard

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 7 of 22 (204753)
05-03-2005 7:16 PM
Reply to: Message 6 by ProfessorR
05-03-2005 6:50 PM


Richard,
SHAME ON YOU!
Are you suggesting that the authors of those stickers had ulterior motives, and weren't just concerned with improving the quality of their children's education? What a terrible suspicious mind you have!
mick

This message is a reply to:
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ProfessorR
Inactive Member


Message 8 of 22 (204754)
05-03-2005 7:19 PM
Reply to: Message 7 by mick
05-03-2005 7:16 PM


Mick, okay, I stand corrected...

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New Cat's Eye
Inactive Member


Message 9 of 22 (204757)
05-03-2005 7:28 PM
Reply to: Message 4 by ProfessorR
05-03-2005 5:46 PM


Mind if I butt in.
Would you care to comment on the statement that "Darwinism" (or the modern theory of evolution) is not a scientific theory? What, in your opinion, makes people issue such a statement?
I asked a question about what we could evolve into, or where evolution was taking us, (which I later realised was asking the theory to make a prediction {a fundamental part of scientific theories}), I got this answer:
Jar writes:
You seem to think that evolution has some directionality? It doesn't. It's simply a history of what did happen.
bold added for emphasis
If this were true, then I wouldn't consider the TOE a theory nor science. Not that I believe this, but this is the sort of thing that makes people issue such a statement.

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Dead Parrot
Member (Idle past 3345 days)
Posts: 151
From: Wellington, NZ
Joined: 04-13-2005


Message 10 of 22 (204764)
05-03-2005 7:40 PM
Reply to: Message 6 by ProfessorR
05-03-2005 6:50 PM


Hmmm...
"atoms and molecules are a theory, not a fact...Electromagnetic field is a theory, not a fact..."
Or try here...

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Matt P
Member (Idle past 4774 days)
Posts: 106
From: Tampa FL
Joined: 03-18-2005


Message 11 of 22 (204765)
05-03-2005 7:47 PM
Reply to: Message 9 by New Cat's Eye
05-03-2005 7:28 PM


Predictive Power
The Theory of evolution is most predictive when the time it takes to observe a generation of organisms is less than the average (career) lifetimes of the individuals making the observation. For instance, a scientist can make predictive assessments on the mutation of bacteria to confer immunity to an antibiotic or to metabolize a novel organic compound, mainly due to the fact that bacteria can reproduce on the order of hours. Likewise, scientists can observe mosquito speciation because their generations are about a dozen per year- London subway mosquitoes are a new species, that, unlike their bird-feeding parent species, now feed on humans. Similarly for guppies and other fast-breeding fish (Most of my examples are from Finding Darwin's God by Kenneth Miller, who is also a Catholic scientist, just so you know).
Predictive power for the ToE for organisms with long generational times is minimal. This is mainly because we don't know how the environment is going to change on the order of 20-30 years, especially with how we are changing it. Additionally, technological innovation is currently more rapid than biologic change, so it's anyone's guess as to what evolutionary changes we'll eventually see.
However, to answer your question, I think that humans will probably become shorter and may eventually be able to metabolize a twinky .

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RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 12 of 22 (204766)
05-03-2005 7:49 PM
Reply to: Message 6 by ProfessorR
05-03-2005 6:50 PM


stickers?

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RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 13 of 22 (204767)
05-03-2005 7:56 PM
Reply to: Message 9 by New Cat's Eye
05-03-2005 7:28 PM


what can be predicted is that change will continue to occur within the human genome
this change is most notable in the new resistance to new diseases and the like, but that does not rule out continued evolution for {women especially} to have less hair on their bodies and the like.
what cannot be predicted is what selection mechanisms will operate to filter the range of variation within a population. this is the chaotic element that rules out fortune telling predictions
we can't predict the weather a week in advance and you want predictions of what humans will be like in a hundred years?
the only thing you can say with some assurance is that it will be different.

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

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RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 14 of 22 (204770)
05-03-2005 8:00 PM
Reply to: Message 11 by Matt P
05-03-2005 7:47 PM


Re: Predictive Power
lol, ya beat me to it
However, to answer your question, I think that humans will probably become shorter and may eventually be able to metabolize a twinky
but what about ...

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
 Message 11 by Matt P, posted 05-03-2005 7:47 PM Matt P has not replied

  
mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 15 of 22 (204771)
05-03-2005 8:02 PM
Reply to: Message 13 by RAZD
05-03-2005 7:56 PM


Just a kind of general reply to Matt, Razd and Dead Parrot,
When we talk about prediction in science, we are not talking about the prediction of the future. We are talking about prediction of the results of an experiment.
I can use the theory of evolution to predict that closely-related sympatric species are more divergent in sexual signalling mechanisms than closely-related alloptric species, for example. Prediction of the future is not required.
Mick

This message is a reply to:
 Message 13 by RAZD, posted 05-03-2005 7:56 PM RAZD has replied

Replies to this message:
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