jeudi 11 juin 2009

Chromosome numbers



series and tinyurl to this one --- see comments

Why is this a problem for evolution? Genes mutate. In each population, sometimes the mutation, sometimes the unmutated gene and sometimes both prevail. If a population splits in two, they will mutate into different ways. If enough genes are different, at last the populations will be genetically too different for mating to occur with offspring viable and fertile. They are two different species.

This link is to an article - in fulltext - dealing with an experiment where speciations is seen as having been directly observed. Read their definitions carefully. "Even though behaviorally isolated species ..." "behaviorally isolated" - well that would make different human cultures count as different species too.

SO WHAT IS THE PROBLEM?

CHROMOSOMES

Genes bunch in chromosomes, and chromosomes are counted in whole numbers. And the number of chromosomes is fairly fixed, and yet mammals have different numbers of chromosomes.

In most species, mammal or not, chromosomes are diploid (Greek for twofold, meaning all of the chromosomes) in the cells making up a single body, haploid (Greek for simple, meaning in all of the chromosomes) in sex cells. Triploid (Greek for threefold, meaning in all of the chromosomes) individuals occur in plants, fish, lizards, birds, they are infertile or selffertilising females, both ways are roads out of sexual reproduction and therefore evolution as usually understood.

Diploid chromosome setups mean that chromosomes go in pairs that hang together at the centromere and branch off to telomeres. Centromeres (middle pieces) and Telomeres (end pieces) are like full stops in genetic information. It is DNA bundled too tight for readability. But they are essential for the RNA-readings of the arms - an arm is whatever part of a chromosome is between one Centromere and one Telomere. Chromosomes have one centromere and two telomeres, except (if I recall correctly) Y-chromosomes that have only two telomeres, one of which counts as centromere because bundling with such of the X-chromosome.

Less chromosomes More chromosomes
Normally for diploid beings:

Sex cells forming halve the number of chromosomes into only one for each pair.

Sex cells meeting and forming new individuals double the number of the sex cell chromosomes, getting back to normal.

Not Normally for diploid beings:
  • Haplosomy (onefold in one single pair) going on to asomy (none in that pair)? Asomy means total lack of one chromosome and means non-viability of embryon. So haplosomy is a non-way. Unless, which is not very likely, all the vital information of a chromosome had been transferred to chromosomes of another pair. In mankind, Y-chromosome haplosomy is not viable, but X-chromosome haplosomy gives infertile or less fertile women. But they are same pair, XX a normal woman, XY a normal man.
  • Robertsonian chromosome fusion, is this how it works?


















    Have I proven too much?

    Mice go in different chromosome numbers, and they seem to be yet one species.

    Okapi may have one or two chromosome pairs or even a pair and a half, for same parts of genome.

  • Chromosome fission - as complex as fusion (study diagrams and handwritten text on image left), plus where does the new centromere or the new telomeres come from?
(P Z Myers claims new centromere comes from locus duplication - but that does not explain new telomere on the intra-centromere side of each split)
  • Trisomy (three chromsomes in one single pair) - means handicap, sometimes to fertility (in sex chromosomes) sometimes to other chromosomes. But a trisomy, even if extended after a generation to tetrasomy, does not mean two pairs where there was one, only four chromosomes to a pair, and that is handicap.
  • Polyploidy: triploidy see above. Tetraploid and octoploid individuals occur in amphibians and plants - that are typically greater or stronger or twice as complex as diploid samples. Mammals are neither amphibians nor plants.

    Even if they could be polyploid, which seems not to be the case, that would not open the way for new pairs forming. Each four chromosomes are the four chromosomes of a pair, not the two by two chromosomes of two pairs.


Theories should in principle be falsifiable. If evolution is a theory, chromosome numbers - as well as other similar creationist arguments - are not theories, but falsifications of this theory.

I think chromosome numbers is such a difficulty (if not downright disproof) that that is why Scientists are very shy about putting on the web articles for free about this subject. On my comments to Non-replies I have been looking for such using a scholar google. Time after time I have only got to the abstract of an article that is readable for paying subscribers only. See list at end of comments.



Hans-Georg Lundahl
en déptnt13 ou 84
30 May/11 June AD 2009

PS, A list of different chromosome numbers from a creationist site:

The Evolution of Species by Means of Increasing Number of Chromosomes
-or-
The Preservation of Complex Life Forms in the Struggle for Life

-By Dr. Kent Hovind-

Number of Chromosomes:

  • Fern 480 The ultimate goal.

  • White Ash 138

  • Carp 100

  • Goldfish 94

  • Sweet Potato 90
  • Turkey 82

    • Chicken 78

    • Dog 78

    • Duck 78 Identical Triplets!

  • Horse 64

  • Cow 60

  • Silkworm 56

  • Cotton 52

  • Amoeba 50

    • Chimp 48

    • Tobacco 48 Identical Twins!

  • Human 46

  • Bat 44

  • Wheat 42

  • Soybean 40


  • Cat 38

  • Starfish 36

  • Apple 34

    • Alligator 32

    • Onion 32 Identical Twins!

  • Frog 26

    • Opossum 22

    • Redwood 22

    • Kidney Bean 22 Identical Triplets!

    • Corn 20

    • Marijuana 20

    • Carrot 20 Identical Triplets!

  • Lettuce 18

  • Honeybee 16

  • Garden Pea 14

    • House Fly 12

    • Tomato 12 Identical Twins!

  • Fruit Fly 8

  • Penicillium 2


Source: DrDino/Kent Hovind - after reading which I searched in Talkorigins.org and got this. Which is where my argument comes from.

Credits to user Jon for giving me the opportunity to refind it.

6 commentaires:

Hans Lundahl a dit…

"http://o-x.fr/292" = biologist P Z Myers saying this is no problem.



He gives a diagram, but no medical or veterinarian cases where chromosome fission has happened before eyes of researchers. Fusion does happen: cancer, Downs, fertility problems. I DID look up Robertsonian fusion on a scholar google, as he said I should.



What he considers sufficient evidence might be related or (to creationists simply) similar species, in which the corresponding parts (remember, there are non-corresponding parts as well) of total genomes are stocked on different numbers of chromosomes. Like his example on an earlier post, where two chimpanzee chromosomes are supposed to correspond to one fusioned human chromosome, because of corresponding genetic material on them.

Hans Lundahl a dit…

This is from a man Myers calls an "ignorant" creationist:



Evidence for Fusion in a Human Chromosome Tells you LITTLE TO NOTHING about whether Humans Share a Common Ancestor with Living Apes
Usually Darwinists argue for human-ape common ancestry based upon alleged "shared errors" in human DNA and ape DNA. But the chromosomal fusion evidence is not a “shared error” argument for human / ape common ancestry, because apes do not have a fused chromosome. The human chromosomal fusion argument focuses on a fusion event that is specific to the human line, and therefore provides a highly limited form of evidence for human / ape common ancestry.




Ignorant of biology or not, he is at least knowledgeable in textual criticism establishing of manuscript history --- as well as logic.



Whether there are common transcription errors had by both apes or men or no, the fusion of #2 (if indeed it was a fusion) is special to man. Whether this fusion adequately explains how men can have evolved from a common ape ancestor or not, it does not prove we actually did.

Hans Lundahl a dit…

That was from "http://o-x.fr/-53" --- And the Miller Told His Tale: Ken Miller's Cold (Chromosomal) Fusion (Updated)

Hans-Georg Lundahl a dit…

This is now accessible on http://o-x.fr/tcu

Hans-Georg Lundahl a dit…

An extra check on chromosome numbers per species ...

Hans-Georg Lundahl a dit…

http://o-x.fr/lsf is the new index post to this series.