How many possible different humans are there?

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In summary, the number of possible humans that can be produced without mutation is essentially infinite due to the vast number of genetic variations and combinations possible in the human genome. Additionally, environmental factors and gene duplications/mutations further increase this number. Therefore, it is impossible to calculate a finite number of genetically distinct humans.
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mikeph
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I'm wondering in terms of genetics... and as a warning my biology knowledge is very limited

From a mathematical point of view, if there are 20,000 genes in the human genome, how do we calculate the number of possible humans that can statistically be produced (without mutation)?

eg. Does each gene correspond to one of A,C,G,T? In which case an upper limit would be 4^20000? Or is this totally wrong? I'm thinking in terms of very rough figures.

Maybe another approach to the question is in terms of DNA sequencing... if someone looks at my DNA, what chance is there that someone else will have the same result? Or that I have the same DNA as someone else?

Obviously some combinations will not work, but am I right in thinking that if any 2 of the 7 billion humans have a child, that there are real and quantifiable boundaries to the human genome that say, without mutation, that "there is a possibility of producing this offspring" with certain DNA, but you're never going to produce an ape- that is too far different from a human.

So there must be a finite number of genetically distinct humans that can be made from combinations of the present human genome... but how can this number be calculated?


Sorry for the ramble, any help much appreciated.
 
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few errors in your post that need to corrected. The A C GT isn't a gene, They are bases. A gene is sequence of bases, could be really long or short. The permutations would be a lot more than you are thinking.

The 2nd problem is that just because you have a different gene, the result protein might not be that different.
 
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By sequencing the DNA from various individuals, scientists have found 15 million single nucleotide polymorphisms, 1 million short insertions and deletions, and 20,000 structural variants (The 1000 Genomes Project Consortium). Assuming each of these sites of variation has only two alleles and that none are synthetically lethal, this puts an estimate of the possible combinations from randomly assorting these variants at 2^(1.6x10^6) or 10^480000.
 
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The question is poorly formed (no insult, ignorance is no bad thing when you strive to correct it). Consider that genetically identical twins are phenotypically different because of differences in their environment. Aside from this fact that genetics are the start, not end, of the answer there is no fixed number and variation of genes. Anyone can be born with gene duplications and/or mutations in those genes creating novel genotypes.
 
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I can understand your curiosity about the number of possible different humans based on genetics. However, it is important to note that this is a complex and constantly evolving area of research, and the exact number of possible different humans is difficult to determine.

Firstly, it is important to understand that the human genome is not just made up of 20,000 genes, but also contains non-coding regions and regulatory elements that play a crucial role in gene expression. Additionally, the interactions between genes and their environment can also influence the expression of traits.

To answer your question about the number of possible humans based on the four nucleotides (A,C,G,T), it is not as simple as 4^20000. This is because genes can have multiple alleles (versions of a gene) and can interact with each other in complex ways. This means that the number of possible genetic combinations is much larger than 4^20000.

Furthermore, the concept of DNA sequencing and comparing it to others is not a reliable way to determine the number of possible humans. This is because DNA sequencing only looks at a small portion of the genome and does not take into account the non-coding regions and gene interactions mentioned earlier.

In terms of calculating the number of genetically distinct humans, it is not possible to give an exact number. This is because the human genome is constantly changing due to mutations and genetic variations. Additionally, factors such as epigenetics (how genes are expressed) and environmental influences also play a role in shaping human diversity.

In summary, while it is intriguing to think about the number of possible different humans based on genetics, it is a complex and ever-changing field of study. As scientists, we continue to learn more about the human genome and its variations, but it is difficult to give a definitive answer to this question.
 

How many possible different humans are there?

The exact number of possible different humans is difficult to determine, as it depends on various factors such as genetic variations and environmental influences. However, one study estimated that there are approximately 100 trillion possible different humans.

What factors contribute to the variation among humans?

Genetic variations, which are inherited from our parents, are one of the main factors contributing to the variation among humans. Additionally, environmental factors such as diet, lifestyle, and exposure to different environments can also impact the physical and behavioral characteristics of individuals.

Can humans continue to evolve and produce even more variations?

Yes, humans can continue to evolve and produce even more variations. Evolution is an ongoing process and is driven by natural selection, genetic mutations, and other factors. This means that humans can continue to produce new and different variations over time.

Are there any limitations to the number of possible different humans?

While there are a vast number of possible different humans, there are some limitations. For example, there are a limited number of genes that can be combined in different ways, and there are physical constraints to how much a human body can vary. Additionally, certain genetic disorders and mutations may limit the range of possible variations.

Do different cultures and societies contribute to the variation among humans?

Yes, different cultures and societies can contribute to the variation among humans. Factors such as cultural practices, traditions, and beliefs can influence physical appearance, behavior, and even genetic traits. This is why there is such a diverse range of human characteristics and variations around the world.

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