33 votes
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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 votes
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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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  • 2,053
24 votes
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The Uniqueness of DNA Paradox

The uniqueness of irises and fingerprints are, as you said, limited to the number of possible permutations of irises and fingerprints. A similar problem exists in computer science, and is known as a ...
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  • 9,314
23 votes
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Why did humans lose their fur?

This is an interesting question, and there are a number hypotheses available to explain this phenomenon. The short answer (as far as I can say after my literature search) is that we don't know the ...
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22 votes

Why do we have more male infants born?

Note: This is based on literature searches I've done a while ago out of general curiosity. I'm in no way an expert on human reproduction. First, I'm not sure if you are asking about evolutionary ...
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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 votes
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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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  • 36k
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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  • 2,877
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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  • 67.5k
15 votes

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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  • 3,772
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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  • 1,270
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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Is it possible for a child to grow taller than their tallest parent?

People can grow taller than their parents. Anecdotally: I'm 185 cm, my parents are 155 cm and 178 cm. Joakim Noah, an NBA basketball player is 211 cm, his dad was 193 cm and mother was 175 cm... how? ...
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12 votes
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Why aren't green eyes more prevalent?

A gene being dominant does not necessarily imply the gene is also common. An easy counterexample is Huntington's disease. The gene is dominant, and only one mutant allele of huntingtin would result ...
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  • 9,314
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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What effect does the Barr body have, in relation to female Turner syndrome?

The reason is that X-inactivation is not complete (Carrell & Willard, 2005; Ahn & Lee, 2008), and as many as 15-25% of X-linked genes escape silencing (Carrell & Willard, 2005; Cheng et al,...
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11 votes
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Father with mutated mtDNA- why isn't his offspring at risk?

...would then be his offspring at risk? Why? No. Generally speaking, fathers do not pass on their mtDNA (Mitochondrial DNA). Why? Because the mitochondria present in oocytes (egg cell) is the mother'...
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  • 9,064
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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  • 2,227
10 votes
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Why has grey hair evolved?

Presumably this means that at least some grey haired humans have noticeable reproductive advantage, or maybe they had it in the recent past. No it doesn't. Natural selection is not that strong, ...
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  • 4,680
10 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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10 votes

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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  • 2,048
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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  • 2,711
9 votes

Why are men stronger than women?

What are the evolutionary explanations for why women are weaker than men (on average), and is this difference adaptive? All of the theories surrounding this fact are speculative; it would be ...
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  • 9,064
9 votes
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Like other animals, why humans don't have species & breeds?

If you with 'humans' refer to our genus Homo (which is often the case), we do have multiple species, see wikipedia for an overview. The difference to many other organism groups is just that all ...
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9 votes

Why do we have more male infants born?

There is an article in the Journal of Popular Science from 1885. However, I do know there is at least one more recent article floating around some where since I read it. At the moment, I can't find it ...
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  • 2,167
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

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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  • 8,671
8 votes

What is the evolutionary cause for various finger lengths?

When you bend your fingers, they all arrive at the same height. I would tend to think that their lengths differ when you keep them straight because they need to have similar length when you bend them. ...
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  • 67.5k
8 votes
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Why do so many people have group O blood?

There are many different variants of O (all loss-of-function) indicating that this mutation has arisen many times in the human population. The prevalence of O is indeed taken as evidence of balancing ...
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