Recent Problems in Evolution - 1995

Table of Contents

Rapid appearance of birds

A recent study has shown that every order of modern birds appeared within a time frame of less than 10 million years at the Cretaceous-Tertiary boundary. Such major diversification seems unlikely in such a short period of time. (Feduccia, A. Explosive evolution in tertiary birds and mammals. Science 267: 637-638, 1995.)

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Ancient Bacteria

Recent advances in molecular biology have allowed scientists to recover ancient Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA encased in amber. This Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA can be amplified many millions of times using a technique called polymerase chain reaction. Although we are not at the level of sophistication seen in the popular movie Jurassic Park, scientists have been able to recover ancient Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA and determine genetic The order of nucleotides in a DNA or RNA molecule, or the order of amino acids in a protein molecule.sequencesfrom biological specimens preserved in amber (1). Recently (May, 1995), scientists were able to recover intact, live bacteria from the stomach of a 25 million year old species of extinct bee (2). This was possible because the bacteria recovered are part the genus Bacillus, which form spores under adverse conditions (i.e., being trapped in a dead bee encased in amber). The ancient bacteria have been grown and compared to the same species alive today (which also lives in the stomachs of modern bees). The results of genetic analysis show that the ancient Bacillus sphaericus differ from the current species by only 6.7%. This is a remarkable discovery, since these bacteria have had 25 million years to "evolve." Since bacteria have a generation time of minutes to hours, this period of time corresponds to over 200 billion generations. How then could we humans have changed by 1-2% in Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA content compared to chimpanzees in at most 300,000 generations? Evolutionists have already began to make excuses to avoid the implications of this new area of research (3).

References

  1. R.J. Cano et. al, Appl. Environ. Microbiol. 60, 2164, 1994
  2. R.J. Cano, K. Borucki, Science 268, 1060, 1995.
  3. J. Fischman, Science 268, 977, 1995.

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Viviparity and placentation must have evolved independently at least 100 times

New data challenges evolutionary mechanisms, since it indicates that viviparity (live birth) and placentation (feeding of fetus through a placenta rather than within an egg) must have evolved independently at least 100 times within the last era. In addition, the evolution of viviparity seems to require placentation, since a lack of placentation is not compatible with viviparity. The authors admit that there is no evolutionary evidence for a gradualistic evolution of viviparity, "However, various Related to the observable traits or characteristics of an organism, for example hair color, weight, or the presence or absence of a disease.phenotypic intermediates postulated by the gradualistic model are either scarce or unrepresented among known forms, including those in which viviparity has evolved at specific and subspecific levels."(Blackburn, D.G. 1995. Saltationist and punctuated equilibrium models for the evolution of viviparity and placentation. Journal of Theoretical Biology 174: 199-216.)

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Human Genetic Diversity is too small according to Darwinian Theories

Scientists have observed that there is a major problem in the human population that doesn't fit Darwinian theory. The genetic diversity of humans is much less than that expected from a population that theoretically speciated several hundred thousands years ago. According to Dr. Maryellen Ruvolo (Harvard University) "It's a mystery none of us can explain." Their conclusion is that the human population must have went through a "population bottleneck" of 10,000 or fewer individuals from 400,000 to 12,000 years ago. However, Jan Klein (Max Planck Institute, T�bingen, Germany) and Dr. Francisco Ayala (University of California, Irvine) say that a population of 10,000 does not represent a bottleneck, since this is the standard breeding population of many species. Another alternative is that modern humans did not evolve from apes, but were created more recently than 400,000 years ago. Many recent studies support this hypothesis (see below). (Gibbons, A. 1995. The mystery of humanity's missing Permanent structural alterations in DNA, consisting of either substitutions, insertions or deletions of nucleotide bases.mutations. Science 267: 35-36.)

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Recent human origins: The "Adam" and "Eve" Theories

Recent studies, nicknamed the "Eve theory," examining the Of or referring to the mitochondria, the organelles that generate energy for the cell.mitochondrial Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA ( Genetic material found in mitochondria, the organelles that generate energy for the cell.mtDNA) of women all over the world, have suggested that modern man (actually women) originated fairly recently (1-3). Scientists chose to examine Genetic material found in mitochondria, the organelles that generate energy for the cell.mtDNA because, being enclosed within the subcellular organelle called the mitochondrion, there is no genetic recombination. All Genetic material found in mitochondria, the organelles that generate energy for the cell.mtDNAcomes from our mothers and is passed down from mother to daughter, since only mitochondria from the egg are used to make up the fetus. By tracing the differences in Genetic material found in mitochondria, the organelles that generate energy for the cell.mtDNA from peoples around the world, scientists have calculated the probable date of origins of humans, 100,000 to 200,000 years ago.

In an even more recent study, published in May, 1995, scientists have examined human origins from the perspective of male genetics (4, 5). Scientists have examined a gene (ZFY), which being on the One of the two sex chromosomes that determines maleness in mammals, carried and passed down from males to males.Y chromosome, is passed down only from father to son. Thirty-eight men were chosen from all over the world (Africa, Asia, Australia, Europe, and Northern, Central, and South America). Scientists determined the actual genetic The order of nucleotides in a DNA or RNA molecule, or the order of amino acids in a protein molecule.sequence in each man for this gene, which is 729 Two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds.base pairs long. To their surprise, all men had identical genetic The order of nucleotides in a DNA or RNA molecule, or the order of amino acids in a protein molecule.sequences (over 27,000 Two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds.base pairs analyzed). Scientists have calculated the most probable date for the appearance of modern man, given the The order of nucleotides in a DNA or RNA molecule, or the order of amino acids in a protein molecule.sequence diversity from modern apes. Using two different models this date is either 270,000 or 27,000 years ago. However, both these models assume that the male population during this period of time consisted of only 7,500 individuals. The date estimates from these models would be significantly reduced if the male population were higher than 7,500, which is very likely. Two separate, more recent studies (November, 1995) using similar techniques looked at larger pieces of the One of the two sex chromosomes that determines maleness in mammals, carried and passed down from males to males.Y chromosome, which would reduce the uncertainty in the calculation of dates. One study examined a gene which was 2,600 Two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds.base pairs and determined an origination date of 188,000 year ago (6). The other study used a very large piece of the One of the two sex chromosomes that determines maleness in mammals, carried and passed down from males to males.Y chromosome (18,300 Two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds.base pairs) and calculated a date for the origin of modern man of 43,000 years ago (minimum of 37,000 and maximum of 49,000 years ago) (7). This latter study also examined Of or referring to the mitochondria, the organelles that generate energy for the cell.mitochondrial Deoxyribonucleic acid: the chemical inside the nucleus of a cell that carries the genetic instructions for making living organisms.DNA from women and determined an origination date of ~100,000 years ago. Although not officially named the "Adam theory," it very well could take on this name, since it predicts that all men originated from one geographic location in the recent past.

A studied published in March, 1996 (8) examined The association of genes and/or markers that lie near each other on a chromosome that tend to be inherited together.linkagedisequilibrium at the human CD4 The place on a chromosome where a specific gene is located, a kind of address for the gene.locus (a T-cell associated antigen) as a means to establish the date of modern human origins. This study determined a maximum origin date of 102,000 years ago based upon the assumption that the Alu (-) Variant forms of a gene at a particular locus, or location, on a chromosome.alleles arose 5 million years ago, or almost immediately after mankind's split from other An order of mammals including man, apes, monkeys, etc., often characterized by large brains and flexible hands and feet.primates. As they stated, "It is likely that the Alu deletion event occurred more recently, in which case our estimates for the date of founding of the non-African populations would also be more recent."

The The association of genes and/or markers that lie near each other on a chromosome that tend to be inherited together.linkage disequilibrium technique is a hot topic of research, with several laboratories exploring human origins using other genetic Multiple places on a chromosome where specific genes or genetic markers are located, a kind of address for the gene.loci (9). It is likely these studies will be publish in the next few months. Dr. Tishkoff says that preliminary studies from Threadlike "packages" of genes and other DNA in the nucleus of a cell. Different kinds of organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes. Each parent contributes one chromosome to each pair, so children get half of their chromosomes from their mothers and half from their fathers.chromosomes 19, 11 and 8 show similar results to that seen on One of the threadlike "packages" of genes and other DNA in the nucleus of a cell. Different kinds of organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes. Each parent contributes one chromosome to each pair, so children get half of their chromosomes from their mothers and half from their fathers.chromosome 12 (the The place on a chromosome where a specific gene is located, a kind of address for the gene.locus of the CD4 gene).

The implications of these recent discoveries are many and far-reaching. Many scientists have discounted the "Eve" studies because of possible explanations other than a recent origin from a single geographic locale. Confirmation of this data using several completely different methods tends to rule out these doubts and makes the conclusions much more certain. These studies shed doubt on most modern theories of evolution that Homo erectus is the predecessor of modern man, since evidence indicates Homo erectus emerged from Africa nearly one million years ago and spread across several continents and disappeared ~300,000 years ago, 250,000 years before modern man appeared. Therefore, it would appear that modern man has no evolutionary ancestor. All of these studies confirm what the Bible says, in that mankind originated from a single geographic locale in the recent past.

References

  1. R.L. Cann, M. Stoneking, A.C. Wilson, Nature 325, 31 (1987)
  2. L. Vigilant, M. Stoneking, A.C. Harpending, K. Hawkes, A.C. Wilson, Science 253, 1503 (1991)
  3. M. Hasegawa, S. Horai, J. Mol. Evol. 32, 37 (1991)
  4. S. Paabo, Science 268, 1141 (1995).
  5. R.L. Dorit, H. Akashi, W. Gilbert, Science 268, 1183 (1995)
  6. Hammer, M.F. 1995. A recent common ancestry for human Y Threadlike "packages" of genes and other DNA in the nucleus of a cell. Different kinds of organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and two sex chromosomes. Each parent contributes one chromosome to each pair, so children get half of their chromosomes from their mothers and half from their fathers.chromosomes. Nature 378: 376-378.
  7. Whitfield, L.S., J.E. Suston, and P.N. Goodfellow. 1995. Sequence variation of the human One of the two sex chromosomes that determines maleness in mammals, carried and passed down from males to males.Y chromosome. Nature 378: 379-380.
  8. Tishkoff, S.A., E. Dietzsch, W. Speed, A.J. Pakstis, J.R. Kidd, K. Cheung, B. Bonn�-Tamir, A.S. Santachiara-Benerecetti, P. Moral, M. Krings, S. Paabo, E. Watson, N. Risch, T. Jenkins, and K.K. Kidd. 1996, Global patterns of The association of genes and/or markers that lie near each other on a chromosome that tend to be inherited together.linkage disequilibrium at the CD4 The place on a chromosome where a specific gene is located, a kind of address for the gene.locus and modern human origins. Science 271: 1380-1387.
  9. Fischman, J. 1996. Evidence mounts for our African origins - and alternatives. Science 271: 1364.

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Cambrian explosion included even chordates

Recent discoveries in Chengjiang, China have revealed that virtually every animal phyla (including many now extinct) appeared during the short geological moment called the Cambrian explosion (1). Contrary to the claims of Darwinism, the appearance of all the diverse phyla of the animal kingdom occurred in a period of less than 10 million years (2, 3). As Stephen Jay Gould has stated, "we have reason to think that all major anatomical designs may have made their appearance at the time." (4).

References

  1. Chen, J.Y., J. Dzik, G.D. Edgecombe, L. Ramskold, G.Q. Zhou. 1995. A possible early Cambrian chordate. Nature 377: 720-722.
  2. Kerr, R.A. 1993. Evolution's big bang gets even more explosive. Science 261: 1274-1275.
  3. Bowring, S.A., J.P. Grotzinger, C.E. Isachsen, A.H. Knoll, S.M. Pelechaty, and P. Kolosov. 1993. Calibrating rates of early Cambrian evolution. Science 261: 1293-1298.
  4. Gould, S.J. 1995. Of it, not above it. Nature 377: 681-682.

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Last updated January 2, 1998

 

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