33
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Do men and women have the same number of genes?
It is true that the Y chromosome is shorter than the X chromosome and that there are more genes on the X chromosome.
Do men have fewer genes?
One could (mis)understand three things in the ...
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33
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If a small population left one continent and sailed to another, would the genes of the population that left show relation to the original population?
If we assume a population of 100 individuals migrated from the Middle East to Central America 2600 years ago and, even if they underwent admixture from the local population, then there would be ...
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20
votes
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How do we know Neanderthals DNA?
Neandertal DNA has been completely sequenced multiple times now, using DNA from bone and tooth samples found in cool or cold environments. The first Neanderthal genome sequence was described in 2010:
...
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18
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“The rhesus macaque is pretty much the closest thing we have to humans” — why?
Short answer:
Chimpanzees are indeed closer, but perhaps...too close. Almost all invasive research on non-human great apes has halted for some time over ethical concerns.
Rhesus macaques are the ...
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16
votes
How do we know Neanderthals DNA?
The answers here give you reference to the first draft genome. Take a look at these papers for high-quality sequences: Prufer et al., 2014 for Altai Neandertal, Meyer et al., 2012 for the Denisova ...
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15
votes
Discrepancy in time for genetic differences between human and chimpanzee to accumulate
Good literature work here and good question +1! In short, your main mistake was that you based your calculations on a single site and not on the whole genome. More info below.
Genome-wide vs sites ...
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15
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If a small population left one continent and sailed to another, would the genes of the population that left show relation to the original population?
From the point of view of genome comparison the signature would be unmistakable, as @user438383 has pointed out in their answer. There may be however other methodological issues undermining this study:...
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14
votes
Can a blood type O be born from AB and A parents?
The ABO blood type is controlled by a single gene (the ABO gene) with three types of alleles inferred from classical genetics: i, IA, and IB. The IA allele gives type A, IB gives type B, and i gives ...
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13
votes
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Why are the genomes of Humans 99.5% the same?
In a genome that is 3 billion base pairs, a difference of 0.5% works out to a difference of 15 million bases. When a single base change can change the amino acid sequence of a protein, that can add up ...
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12
votes
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Are males taller than females in humans?
Are males taller than females?
Best data I could find come from the Statistical Abstract of the United States (1999) > Section 3. Here is a table reporting the percentage of the male and female ...
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11
votes
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How does a fetus retain a blood group different from its mother?
The maternal and fetal blood circulation systems are completely separate. The embryo's blood cells start developing at around week 5 gestational age (3 weeks after conception), the same way any other ...
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11
votes
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What is positive and negative supercoiling?
According to this powerpoint from the SIU School of Medicine:
Right handed supercoiling = negative supercoiling (underwinding)
Left handed supercoiling = positive supercoiling
And from this Boston ...
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11
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If a DNA letter is one of A,T,C and G, and there are 3 billion base pairs, why don't we say that there are 6 billion letters in the genome?
If a DNA letter is one of A,T,C and G, and there are 3 billion base
pairs, why don't we say that there are 6 billion letters in the genome?
It is a convention, and stating the actual number of ...
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10
votes
Why is male balding so common in comparison to female balding?
Let's start off by saying that "baldness" is a very broad term... it includes not only hair loss but also miniaturization, which accounts for the majority of the phenotypic "baldness&...
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9
votes
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How close genetically is the most human-like chimpanzee to the most chimp-like human?
You may be interested in this 2005 Nature paper from the Chimpanzee Sequencing and Analysis Consortium: Initial sequence of the chimpanzee genome and comparison with the human genome. It breaks down ...
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9
votes
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If a mother had a child with her own son, could a paternity test yield positive result for the son's father?
Let's approach some different methods of distinguishing parents:
1: The Y chromosome. These are passed down from father to son. Therefore, if the baby is male, its Y chromosome will be the same as ...
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9
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Why is lower case used in front of a capitalized acronym (e.g. rDNA)?
It's just a stylistic approach because "DNA" or "RNA" is an abbreviation by itself that has become a whole noun. Those terms clearly separate the modifier from the overall DNA/RNA. It makes it easier ...
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9
votes
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Are all genetic disorders inherited?
Are all genetic disorders inherited?
Not all individuals with a genetic disorder inherited that disorder. Some genetic disorders are caused by spontaneous mutations.
Is cancer a genetic disorder?
...
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9
votes
When is the sex of a human not determined by their chromosomes?
To answer points 1 and 2:
People born karyotypically male (XY) with complete androgen insensitivity syndrome (AIS), can be born without developed male genitals. People with a certain set of sex ...
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8
votes
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Understanding ancestry testing mathematically
I'll give here a simple, non-technical answer because I'm assuming you don't need to actually perform an analysis of ancestry.
So, detecting ancestry is a non-trivial task. Given your genome ...
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8
votes
What is the latest consensus on the causes of sexuality?
You are correct. The Nature article to which you refer does contain the line, "There is no gay gene." But that can't be, and is not, the conclusion. In context:
The largest study to date on ...
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8
votes
When is the sex of a human not determined by their chromosomes?
There is a a whole mess of inhibitors and activators proteins that need to be triggered for typical sexual development, a mutation or error in any one can lead to atypical results even if they have ...
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7
votes
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What causes the range of severity of neurological deficits in Down's syndrome?
The symptoms of Down syndrome occur due to overexpression of genes present on the duplicated chromosome.
If possessing an extra chromosome meant an equivalent change in gene expression, one would ...
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7
votes
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What is the difference between a human being, a Homo sapiens, and a Neanderthal?
Homo sapiens / Homo sapiens sapiens
Human being, in the popular culture generally refers to modern humans, called either Homo sapiens or Homo sapiens sapiens. The existence of the two names will make ...
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7
votes
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Are MHC Proteins the Most Polymorphic Human Proteins Known?
Yes. There are many MHC (MHC in humans is called HLA) genes. The classical loci — Class I A, B, and C, and Class II DP, DQ, and DR — are the most polymorphic.
Here's a table from a 2002 article ...
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7
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Why is my blood group O -ve?
Humans are diploid organism. So humans have two copies of every chromosome and gene.
When a person has B blood. We mean that the blood cells of that person expresses the B antigen.
To produce the ...
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7
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How it is determined that a particular gene or set of genes is responsible for a trait?
In the below list of technics, I am assuming we are talking about haploid individuals (to avoid discussion about dominance relationship) and assuming no epistasis but the technics can 'easily' be ...
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7
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Is most of the human genome functionless “junk DNA”?
What is junk DNA?
The term junk DNA is not used that often in the scientific literature and when it is it is often used very generally, often early in the introduction. It generally refers to any non-...
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7
votes
Accepted
Human genetic diversity in Africa in comparison with the rest of the world
Here is a tree based on mitochondrial DNA variations in human populations.
van Oven M, Kayser M. Hum Mutat. 2009 Feb;30(2):E386-94.
Updated comprehensive phylogenetic tree of global human ...
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Only top scored, non community-wiki answers of a minimum length are eligible