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Is 99.9% of Human Genome The Same?

Iqbal Latif - 6/13/2007

Poverty and human sufffering was a common theme in Harvard University class of 2007. Former president Bill Clinton urged Harvard University's graduating seniors yesterday to serve others in an age of uncertainty. "For all the opportunity, there's a lot of inequality," he told an estimated crowd of 20,000 gathered on one of Harvard's main yards during yesterday's Class Day ceremony. "The world is awash today with political, psychological conflicts, which require us to divide up and demean people." "The world is awash today in political, religious, almost psychological conflicts, which require us to divide up and demonize people who aren't us," he said. Clinton drew on the examples of previous Class Day speakers and his own personal hero, Nelson Mandela, who led the fight against apartheid in South Africa, to inspire seniors.

"I hope that you all share Martin Luther King's dream, embrace Mandela's spirit of reconciliation, support Bono's concern for the poor, and follow Mother Theresa's life and do some active service," he said.

Last Friday, Harvard University's most famous dropout finally got his college degree. Bill Gates, who co-founded Microsoft Corp. and became the world's richest man after leaving Harvard in 1975, returned Thursday to accept an honorary degree and speak at the school's 356th commencement. "I will be changing my job next year," Gates said, referring to his plan to give up his day-to-day role at Microsoft in July 2008. "It will be nice to finally have a college degree on my resume."

Gates has been concentrating on philanthropy, through the Bill & Melinda Gates Foundation he began with his wife.He urged graduates to work to end poverty and preventable diseases worldwide. "You have technology that members of my class never had. You have an awareness of global inequity, which we never ha d," Gates said. "Be activists. Take on the big inequities. It will be one of the great experiences of your lives.

Beyond the niceties it was Clinton addressed that I thought was intellectually quite provocative . Delivering the Harvard annual Class Day speech yesterday, Clinton stressed the commonality of human existence, noting that humans share more than 99.9 percent of the genome sequence. Two-term U.S. President Bill Clinton challenged the 1,667 graduating members of the Class of 2007 yesterday to look beyond individual differences and find what is common across humanity. "The great temptation," Clinton said, "is to believe that the one-tenth of one-percent of you that is different and which brought you here [to Harvard]...is really the sum of who you are." "That is the trap into which you must not fall," Clinton said.




I think unity within humankind is only possible based on promotion of diversity of mankind. Embedded cultural and biological differences that human kind displays cannot be underplayed or treated with broad brushing attempt of false science. Peace is only possible if unity in diversity is emphasised, commonality of genome and egalitarianism of mental capacities is a pitiable approach, great politics but poor science in my belief.



In his address, Clinton highlighted several challenges facing the world today, including poverty, terrorism, disease, and climate change. Despite these challenges, Clinton stressed that solutions could be found. "The inequality is fixable and the insecurity is manageable," he said. But Clinton warned the audience that the world's most pressing problem was the prevailing belief that "our differences are more important than our common humanity."




I wondered from where did Clinton borrowed the idea of 99.9 percent commonality of the genome sequence, as a firm believer in 'Oneness of Mankind' this was music to my ears, so I researched a little bit that led me to Genome research study on 'Regional Patterns of Gene Expression in Human and Chimpanzee Brains.' The challenges of the study was to better understand in the wake of the completion of the human genome sequence the genetic and evolutionary background of phenotypic traits that set humans apart from our closest evolutionary relatives, the chimpanzees.


There is no scientifically proven 99.9 percent commonality rather the evidence is heavily weighed towards differences between individuals. 'Consumed with incredulity I started to wonder how the genes effecting brain function were related to the presumed common ancestor of Man and Chimpanzee. What I found was astonishing and I don't mean the differences between chimpanzees and humans, which are considerable. The differences within their respective species and, even more surprising, from one individual to another are far larger then I realized. In fact, 22% of the genes that showed differences between humans and chimpanzees where due to differences between individuals within their respective speci es.' (Mark Kennedy) http://www.iscid.org/boards/ubb-get_topic-f-6-t-000603.html.

What the study has discovered is that within both human and chimpanzee individuals, the transcriptomes of the cerebral cortex are very similar to each other and differ more between individuals than among regions within an individual. In contrast, the transcriptomes of the cerebral cortex, the caudate nucleus, and the cerebellum differ substantially from each other. Between humans and chimpanzees, 10% of genes differ in their expression in at least one region of the brain. The majority of these expression differences are shared among all brain regions. Whereas genes encoding proteins involved in signal transduction and cell differentiation differ significantly between brain regions within individuals, no such pattern is seen between the species. Furthermore, genes that show an elevated expression level in humans are statistically significantly enriched in regions that are recently duplicated in humans.

Four regions of the cerebral cortex (dorsolateral prefrontal cortex, anterior cingulate cortex, primary visual cortex, Broca's area), the central part of the cerebellum (Vermis cerebelli), and the caudate nucleus were dissected in three adult male humans and three adult male chimpanzees. In addition, the premotor cortex and the area homologous to Broca's area in the right hemisphere were isolated from three humans.

Total RNA from each sample was isolated, labeled, and hybridized to Affymetrix oligonucleotide arrays containing probes to ~10,000 human genes. All reliably measured expression differences within the species were summarized for each pairwise comparison and visualized in a multidimensional scaling plot for humans and chimpanzees. Although the differences among the individuals are substantial, the caudate nucleus, the cerebellum, and the cerebral cortex regions are clearly differentiated in one dimension of the plot.


In contrast, all regions of the cerebral cortex group together according to the individual from which they derive rather than according to the respective regions. This effect is particularly pronounced in humans, but also apparent in chimpanzees when the caudate nucleus and cerebellum are excluded from the analysis. When the expression differences within the brain are compared in the two species, the distance between the cerebellum and each of the other five brain regions studied is found to be slightly but significantly greater in humans than in chimpanzees (p = 0.015 for Broca's area, p = 0.009 for prefrontal cortex, p = 0.034 for primary visual cortex, p = 0.025 for anterior cingulate cortex, and p = 0.018 for caudate nucleus, Student's t-tests), but no significant differences are seen for any other pairs of regions (p > 0.05).




On Clinton argument that "The great temptation," Clinton said, "is to believe that the one-tenth of one-percent of you that is different and which brought you here [to Harvard]...is really the sum of who you are." "That is the trap into which you must not fall,"


I would argue differently, are we born genetically equal? Do we have a level playing field, may be not, the surroundings and our upbringing have an impact on our biological construction that is what science tells us and that in turns decides changes in the landscape of our potential noticeably. If inequities have to be address and poverty eradicated we need to appreciate the impact of our surroundings on our biological capacities, impairments that destroy embryonic competence and continues until teens need radical rethinking of strategies.Those who end up in Harvard most likely have more similar transcriptomes of the different cortex regions and the reason they end up in Harvard is for that difference. When gene expression differences of the cerebral cortex are analyzed between individuals, it becomes clear that the transcriptomes of the different cortex regions are more similar within individuals than between individuals.


The cerebral cortex in involved in many complex brain functions including memory, attention, perceptual awareness, "thinking", language and consciousness. "In the cerebral cortex, the biggest difference in gene expression is between the primary visual cortex and the anterior cingulate cortex in both humans and chimpanzees, where 193 and 227 genes differ in expression in humans and chimpanzees, respectively." (Cerebral Cortex, Vol. 12, No. 7, 671-691, July 2002).There is definitely some connection to the external events that differ from individual to individual, our gene expressions tends to signal that. Childhood, rearing, surrounding and milieu in which a human mind grows may help some variation of the structure of the cerebral cortex.


It is noteworthy that regions of the cerebral cortex differ approximately twofold more among the humans than among the chimpanzees. Because this is not true for the caudate nucleus and the cerebellum, this is unlikely to be caused by undetected differences in RNA quality or to post mortem conditions affecting the brain as a whole. It is not likely to be caused by differences in the amount of DNA sequence variation within the species because chimpanzees carry on average more DNA sequence differences between individuals than humans (Kaessmann et al. 1999). A possible explanation is that the cerebral cortex may be more influenced by environmental and physiological conditions than the other brain regions and that the humans differ more than the chimpanzees in living conditions. This is compatible with the fact that genes highly variable among humans are involved in cell–cell signaling and cell adhesion (data not shown). Alternatively, there might be more individual differences in how the cerebral cortex is formed in humans than in chimpanzees, because in humans the myelinization of parts of the cortex is finalized only in the late teens, whereas it is finished earlier in chimpanzees.


One other possibility is that it reflects individual differences in how the cerebral cortex is formed during fetal life. This process involves large numbers of migrations of cells and formation of connections between them that cannot be genetically predetermined but has to involve stochastic or epigenetic events that will differ from individual to individual. However, it is also possible that it reflects responses of different individuals to environmental or physiological differences throughout life or immediately before death. Only the systematic study of a larger number of individuals will be able to resolve the basis for the inter-individual differentiation of the cerebral cortex.


Concord promoted on erroneous knowledge will only complicate matters. Clinton addressed contained material misrepresentations of facts to a unique gathering of future leaders, I liked his approach to eradicate differences by being more open to the ideas of unity of mankind but the argument of genome commonality is bad science and has no rationale starting point. I thought it needs definite repudiation. We as mankind are a varied tribe; our capacities are different so is our genome structures that sometime may differ due to our external conditions. Let's improve conditions globally where poverty and negligence incorporates poor evolution of mental capacities, the improvement in cerebral cortex for human being continues until teens it where we need to work on to attack extremism, new schools and new measures to include everyone on the bandwagon of progress that would definitely need mega effort globally if extremism needs to be stemmed. If the science says so we should believe in it.