The Search for Genetic Eve and Adam

Divergence Points 5-7 Million Years Ago (MYA)– Divergence from the Chimpanzee Lineage 5-7 Million Years Ago (MYA)– Divergence from the Chimpanzee Lineage 4.4+ MYA Ardipithecus Ramidus – first know Hominid 4.4+ MYA Ardipithecus Ramidus – first know Hominid It is not known if this was part of human descent chain or even actually bipedal. It is not known if this was part of human descent chain or even actually bipedal. 3.9 – 4.2 MYA Australopithecus Anamensis – Definitely bipedal 3.9 – 4.2 MYA Australopithecus Anamensis – Definitely bipedal

From Anamensis to Sapiens Australopithecus Anamensis Australopithecus Anamensis Australopithecus Afarensis Australopithecus Afarensis Homo Habilus Homo Habilus Homo Erectus – 1.81 – 1.61 MYA Homo Erectus – 1.81 – 1.61 MYA Homo Sapiens Homo Sapiens Transition Species – 400,000 years ago Transition Species – 400,000 years ago Homo Sapiens Sapiens – 200,000 years ago Homo Sapiens Sapiens – 200,000 years ago Homo Sapiens Neanderthalensis – 200,000 years ago Homo Sapiens Neanderthalensis – 200,000 years ago Evidence seems to indicate that H. Sapiens Sapiens and H. Sapiens Neanderthalensis are not as far apart as once thought. They may be sub-branchs of the same tree that recombined. Evidence seems to indicate that H. Sapiens Sapiens and H. Sapiens Neanderthalensis are not as far apart as once thought. They may be sub-branchs of the same tree that recombined.

Theory’s of Human Evolution 1. Multi-regional Model H. Sapiens Sapiens transitioned from H. Erectus across a wide portion of Africa and Eurasia. H. Sapiens Sapiens transitioned from H. Erectus across a wide portion of Africa and Eurasia. Fossil evidence shows that either H. Sapiens spread very fast after transition or transitioned in multiple areas. This is supported by H. Sapiens Sapiens and H. Sapiens Neanderthalensis. Fossil evidence shows that either H. Sapiens spread very fast after transition or transitioned in multiple areas. This is supported by H. Sapiens Sapiens and H. Sapiens Neanderthalensis. Genetic exchange across the area would have occurred to accomplish this. Genetic exchange across the area would have occurred to accomplish this.

Theory’s of Human Evolution Problems with Multiregional Model Problems with Multiregional Model Would require persistent and extensive migration patterns to disperse the necessary genes. Would require persistent and extensive migration patterns to disperse the necessary genes. H. Erectus existed in China and Java for at least 100,000 years after emergence of H. Sapiens Sapiens indicating a slow migration from the transition point. H. Erectus existed in China and Java for at least 100,000 years after emergence of H. Sapiens Sapiens indicating a slow migration from the transition point.

Theory’s of Human Evolution 2. Out of Africa Theory Noted from the fact that African populations have more differences between themselves than the rest of the human genotypes. Noted from the fact that African populations have more differences between themselves than the rest of the human genotypes. It is thought that transition was actually from a small number of individuals. It is thought that transition was actually from a small number of individuals.

Theory’s of Human Evolution 3. Back to Africa Theory Early H. Sapieans transitional forms evolved in central to west Eurasia, then migrated to Africa and hybridized with H. Erectus and other hominids. Early H. Sapieans transitional forms evolved in central to west Eurasia, then migrated to Africa and hybridized with H. Erectus and other hominids. The fact that Eurasians are more closely related to each other than to Africans supports this. The fact that Eurasians are more closely related to each other than to Africans supports this. This transition would still have been from an originally relatively small number of individuals. This transition would still have been from an originally relatively small number of individuals.

Searching for Eve Mitochondrial DNA Technique Mitochondrial DNA Technique mtDNA exists outside the cell nucleus mtDNA exists outside the cell nucleus mtDNA is exclusively inherited along the maternal line mtDNA is exclusively inherited along the maternal line

mtDNA Study A.C. Wilson and R.L. Cann, 'The Recent African Genesis of Humans,' Scientific American, April 1992, pp A.C. Wilson and R.L. Cann, 'The Recent African Genesis of Humans,' Scientific American, April 1992, pp Used 100 ethnically diverse individuals. Used 100 ethnically diverse individuals. The common mtDNA ancestral sequence was coalesced to a “Eve” about 200,000 years ago. The common mtDNA ancestral sequence was coalesced to a “Eve” about 200,000 years ago.

Searching for Adam The Y chromosome is exclusively passed thru the Paternal lineage The Y chromosome is exclusively passed thru the Paternal lineage The ZFY gene on the Chromosome was picked for a study. The ZFY gene on the Chromosome was picked for a study.

ZFY Study R. L. Dorit, H. Akashi, and W. Gilbert, 'Absence of Polymorphism at the ZFY Locus on the Human Y Chromosome,' Science, vol. 268, pp , 1995 R. L. Dorit, H. Akashi, and W. Gilbert, 'Absence of Polymorphism at the ZFY Locus on the Human Y Chromosome,' Science, vol. 268, pp , 1995 Compared 38 men of diverse geographical origins. Compared 38 men of diverse geographical origins. Their common ZFY ancestral sequence was coalesced to a “Adam” about 270,000 years ago. Their common ZFY ancestral sequence was coalesced to a “Adam” about 270,000 years ago.

Problems with Studies mtDNA is 16,000 nucleotides in size. mtDNA is 16,000 nucleotides in size. Human DNA has 6,000,000,000 nucleotides Human DNA has 6,000,000,000 nucleotides 400,000 times as much DNA exists which could and would have been inherited from other individuals than “Eve”. 400,000 times as much DNA exists which could and would have been inherited from other individuals than “Eve”. mitochondria genes do not normally recombine. mitochondria genes do not normally recombine. They seem to follow the mathematical rules more associated with bacterial genetics than human genetics. They seem to follow the mathematical rules more associated with bacterial genetics than human genetics. Seemingly small increases in efficiency <1% can quickly and easily become the predominate characteristic in the population. Seemingly small increases in efficiency <1% can quickly and easily become the predominate characteristic in the population.

Problems with Studies In the search for “Adam”, the search did not include enough of the chromosome In the search for “Adam”, the search did not include enough of the chromosome The ZFY gene is only a portion of the overall chromosome, total coalesced could be very different. The ZFY gene is only a portion of the overall chromosome, total coalesced could be very different. Both studies shown had too few starting candidates Both studies shown had too few starting candidates “Eve” and “Adam” coalesced at very different time spans. “Eve” and “Adam” coalesced at very different time spans. “Adam” coalesced well into the transition period between H. Erectus and H. Sapiens “Adam” coalesced well into the transition period between H. Erectus and H. Sapiens

Genealogy Gene Genealogy Gene Genealogy A gradually coalesced towards a unique DNA sequence (the root of the tree) A gradually coalesced towards a unique DNA sequence (the root of the tree) Individual Genealogy Individual Genealogy An increase by a factor of two each generation of ancestors which contributed to the genetic make- up of the individual. An increase by a factor of two each generation of ancestors which contributed to the genetic make- up of the individual.

Human Diversity It has been estimated from analysis of the HLA immune genetic complex that human populations have never sunk down below a 50 or 100 thousand population [Ayala & Escalnte, et al1995, p205]. It has been estimated from analysis of the HLA immune genetic complex that human populations have never sunk down below a 50 or 100 thousand population [Ayala & Escalnte, et al1995, p205]. The Genetic make-up of Humans would have come from many individuals over the course of many generations, not a single “Eve” or “Adam”. The Genetic make-up of Humans would have come from many individuals over the course of many generations, not a single “Eve” or “Adam”.

Conclusion There is not any single individual at this time that could be identified as the Mother or Father of the Human race. There is not any single individual at this time that could be identified as the Mother or Father of the Human race. We have many genetic Mothers and Fathers however the their genes have all been jumbled up through generations of sexual reproduction. We have many genetic Mothers and Fathers however the their genes have all been jumbled up through generations of sexual reproduction. It is possible future techniques “may” allow the discovery of a genetic “Adam” but it is very likely that this “Adam” might not be what we consider Human. It is possible future techniques “may” allow the discovery of a genetic “Adam” but it is very likely that this “Adam” might not be what we consider Human. It is doubtful that any individual “Eve” could ever be identified because of the gene scrambling seen thru sexual reproduction. It is doubtful that any individual “Eve” could ever be identified because of the gene scrambling seen thru sexual reproduction.

References C Ayala, F.J Adam, Eve, and Other Ancestors: A Story of Human Origins Told by Genes. HPLS 17: [similar to: Ayala, F.J Genes and Origins: The Story of Modern Humans. Book review of The History and Geography of Human Genes by L.L. Cavalli-Sforza, P. Menozzi, and A. Piazzo. J. Mol. Evol. 41: ] C Ayala, F.J Adam, Eve, and Other Ancestors: A Story of Human Origins Told by Genes. HPLS 17: [similar to: Ayala, F.J Genes and Origins: The Story of Modern Humans. Book review of The History and Geography of Human Genes by L.L. Cavalli-Sforza, P. Menozzi, and A. Piazzo. J. Mol. Evol. 41: ]HPLS 17: HPLS 17: Science and Nature: Genes. The Truth About Adam and Eve Science and Nature: Genes. The Truth About Adam and Eve Ayala, F.J. The myth of eve: molecular biology and human origins. Science 270, (1995). Ayala, F.J. The myth of eve: molecular biology and human origins. Science 270, (1995). King MC Motulsky AG 2002 Mapping human history. Science 298; King MC Motulsky AG 2002 Mapping human history. Science 298; Evolution - May 1999: Re: Mitochondrial Eve Discussion Thread at American Scientific Affiliation (ASA) Evolution - May 1999: Re: Mitochondrial Eve Discussion Thread at American Scientific Affiliation (ASA) Evolution - May 1999: Re: Mitochondrial Eve Evolution - May 1999: Re: Mitochondrial Eve ScienceDaily New Fossil Study Rejects "Eve Theory" And Supports Diverse Ancestry Of Modern Humans ScienceDaily New Fossil Study Rejects "Eve Theory" And Supports Diverse Ancestry Of Modern Humans New fossil study rejects ‘Eve theory’ and supports diverse ancestry of modern humans; Diane Swanbrow, The University Record, January 22, 200, New fossil study rejects ‘Eve theory’ and supports diverse ancestry of modern humans; Diane Swanbrow, The University Record, January 22, 200, University RecordThe University Record