Questions tagged [human-genetics]

The scientific study of inheritance as it occurs specifically in human beings.

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38
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6answers
48k views

Do humans have enough biological differences to be grouped into races or subspecies?

After my online research on the subject, I learnt that, biologically speaking, many scientists believe that there is no such thing as a race. Homo sapiens as a species is only 200,000 years old, which ...
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5answers
52k views

How many people are required to maintain genetic diversity?

Imagine humans were to colonize a distant planet and it was a single one-way trip. How many people would they need to bring? Obviously 2 is the minimum, but that would result in a lot of inbreeding. ...
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2answers
3k views

What causes the range of severity of neurological deficits in Down's syndrome?

It's known that the severity of symptoms caused by a trisomy 21 varies from individual to individual. Part of the explanation for this range of severity is the finding that 94% of Down's syndrome ...
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4answers
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Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
17
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2answers
55k views

Why do we assume that the first humans were dark-skinned?

According to the article Dark skin and blue eyes: How Europeans once looked: It is widely accepted that Man's oldest common forefather was dark skinned, and that people became more pale as they ...
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2answers
1k views

Why do we have more male infants born?

For every 104 male babies, we have 100 female babies and there are statistics which are more reliable. (Those tell us that we have 997 female infants born per 1000 male infants born.) What is the ...
16
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2answers
6k views

How is eye color in humans inherited?

In high school we studied the inheritance of eye color, as it was explained to us in the most simple way: blue eye color is a recessive, monogenic, autosomal trait. Now I know that it is a bit more ...
15
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5answers
10k views

Do men and women have the same number of genes?

As far as I know, humans have 23 pairs of chromosomes, each one which contains a particular amount of genes. But in the "last" pair, men have a XY pair chromosome, and women have a XX pair chromosome. ...
15
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2answers
583 views

Is the function of adjacent genes correlated?

Do genes that occupy a similar locus on the genome have correlated function, specifically in human beings? It is my understanding that adjacent genes are inherited together, and so location plays a ...
15
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2answers
593 views

What is the contribution of viruses to the evolution of mankind?

I'm interested in horizontal gene transfer in bacteria, viruses, and organisms such as Bdelloid Rotifers. I've just read in Carl Zimmer's 'A Planet of Viruses' the following passage: As a host cell ...
14
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2answers
2k views

The Uniqueness of DNA Paradox

How can everyone have unique iris and fingerprints? After a certain amount of human beings have lived on earth, wouldn't it be possible to exhaust all possible combinations? The same principle ...
14
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4answers
702 views

Questions to ask to a panel of people that will be sequenced

Some genes have been shown to be associated with left-handedness. Working with some clinicians, I've recommend them to ask their patients (whose genome will be sequenced) if they are "right or left-...
14
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1answer
2k views

Could humans and chimpanzees hybridize?

In some cases two species can hybridize. For example, Tigers and lions can hybridize to produce "Ligers". Would it also be possible for humans and chimpanzees (or any other species) to hybridize ? ...
13
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3answers
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How do we know Neanderthals DNA?

According to this article, a small amount of Neanderthal DNA was introduced into the modern human gene pool. How do biologists even know what the Neanderthals' DNA look like? The article doesn't ...
13
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1answer
29k views

Will a bone marrow transplant change one's blood type?

Will a bone marrow transplant change one's blood type? Or is the donor blood type matched with the person before transplant?
12
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3answers
598 views

Number of beneficial mutations cataloged?

I can see from Wikipedia that there are possibly thousands of harmful mutations that have been cataloged and linked to disease. There are also unnumbered neutral mutations. But, does anyone know how ...
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5answers
2k views

Why has grey hair evolved?

A vast majority of humans get at least some grey hair as they age. As far as I know this applies to both genders and all races. Presumably this means that at least some grey haired humans have ...
11
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1answer
17k views

Why are men stronger than women?

What are the evolutionary explanations for why women are physically weaker than men (on average), and is this difference adaptive? See figure one here. I suppose that something puts pressure on men ...
11
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1answer
4k views

Did the eugenics program in Nazi Germany have a measurable effect? [closed]

Did the killing or sterilisation of people considered as living a "life unworthy of life" in Nazi Germany have any measurable effect on the "average health" of Germany? Is there any statistical ...
11
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2answers
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Online phylogenetic tree of human lineages

I am looking for a source of information about the diversity of human lineages and their relationships. With a quick google search it is easy to find this type of tree A perfect online resource ...
11
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1answer
15k views

Why do humans seem so much more prone to disease than animals? [closed]

It seems like when we observe animals in the wild, the occurrence of noticeable disease in adult individuals is much lower than in humans. Why? There are a number of reasons that this could happen, ...
10
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3answers
762 views

Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

One of the major results of the Human Genome Project (HGP) was that humans have far fewer separate genes than previously thought. From a 2004 article about the HGP: Francis S. Collins, director of ...
10
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1answer
252 views

Is there any evidence that humans have faced extinction before?

Have we as a species faced extinction in the past? Resulting in a 'population bottleneck'? If so, what genetic evidence is there of this occurring?
10
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1answer
2k views

Why aren't green eyes more prevalent?

Why aren't green eyes more prevalent, given that the green allele is dominant over the blue one? My understanding is that human eye colour is determined by two genes: 1) HERC2, with alleles Bx, BB ...
10
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1answer
2k views

Why are certain aneuploidies more common?

Certain aneuploidies such as trisomy-21 (Downs syndrome), trisomy-18 (Edward syndrome), Turner syndrome (XO) etc are more common than others. I had a vague thought that it is related to chromosome ...
10
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1answer
47k views

What is positive and negative supercoiling?

Is the following correct? Positive supercoiling = the coiling of DNA helix (B-DNA) on itself during intesified coiling of the two DNA stands in right handed direction negative supercoiling = the ...
10
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1answer
279 views

Why do so many people have group O blood?

Please forgive me in case my question wouldn't make much sense. I was reading about ABO blood groups on Wikipedia, where I learnt that O is a recessive allele, and that it seems the A allele predates ...
10
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1answer
237 views

How it is determined that a particular gene or set of genes is responsible for a trait?

How it is determined that a particular gene or set of genes is responsible for a trait? Is it just a statistical analysis of people showing and not showing the trait and the genes they have (or don't ...
9
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3answers
663 views

Human genetic diversity in Africa in comparison with the rest of the world

Background The claim ... Most of the genetic diversity in humans is in Africa ... is quite common. On Biology.SE, it is easy to find posts that make this claim. Consider for example: Do humans ...
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2answers
1k views

Cause of hexadactylisim in Amish people

Is it caused by inbreeding of many generations within an isolated population?
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2answers
7k views

Like other animals, why humans don't have species & breeds?

Like other animals, why don't humans have species & breeds ? Even my pet dog is one type of breed, but we (humans) lack breeds & species? What is the main reason?
9
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2answers
185 views

Is there any difference in terms of personal healthcare between complete DNA sequencing and SNPs genotyping?

There are several companies (most notably 23andMe) providing SNP genotyping for individuals claiming that there is no sense for individual in obtaining full genome sequence since only small part of it ...
8
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4answers
312 views

Why are males more likely than females to have autism spectrum disorder?

The male to female ratio in autism spectrum disorder is around 4:1. However it seems ASD is not a simple X-linked disorder. Then how is it possible males are more susceptible than females, if the ...
8
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3answers
889 views

How close genetically is the most human-like chimpanzee to the most chimp-like human?

I understand that: Chimpanzees are the closest species to humans genetically. Only 1%-6% of their genes are different. Within any species there is genetic diversity, i.e. no two individuals have the ...
8
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1answer
3k views

Are males taller than females in humans?

Is there any scientific evidence that in humans males are taller than females? And if so, what is the reason that they are taller (please include genes or hormones that accounts for human growth and ...
8
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2answers
7k views

If a mother had a child with her own son, could a paternity test yield positive result for the son's father?

Let's imagine a family composed of Mr A and Mrs B, who have a son named John. Now, if for whatever twisted reason, John had a child with Mrs B, could a paternity test yield positive result for Mr A ? ...
8
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3answers
514 views

What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?

Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve. But at the time she lived there was a different matrilineal ...
8
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2answers
10k views

Why babies cry after they are born?

Well I have noticed that almost all of the babies cry after birth, but some of them (1 to 1,000,000? births) don't cry. So, we have: Why is this happening (the cry after birth)? Also why animals ...
8
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1answer
158 views

Horizontal gene transfer from humans

It is known that some viruses embed themselves in the human genome. Is there a mechanism by which human genes can be transferred to other animals or plants by means of viruses shuttling them from ...
8
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1answer
918 views

How do the pharmacodynamics of the NSAIDs differ and are there “resistant” COX phenotypes?

I know that the non-steroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen, naproxen) affect the enzymes cyclooxygenase (types I and II). Is there any difference in the degree to which these ...
7
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3answers
70k views

Is it possible for a child to grow taller than their tallest parent?

I have heard that offspring can't grow taller than either of their parents but I've also heard that sometimes some gene activation can skip generations. Is it possible for a child to grow taller than ...
7
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3answers
624 views

Are there genes in humans from the common ancestor of all organisms?

How long ago can human genes be traced? Are there any genes that go back unchanged to the beginning of life on Earth? And if so, how many?
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2answers
1k views

Father with mutated mtDNA- why isn't his offspring at risk?

Mothers transmit their mitochondria (and therefore mtDNA) to their offspring and fathers don't. Lets assume that father had a mutation of the gene that encodes mtDNA, would then be his offspring at ...
7
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2answers
14k views

What effect does the Barr body have, in relation to female Turner syndrome?

Why do persons with Turner syndrome have developmental abnormalities, when normal XX-females do not, even though they only have 1 active X chromosome? From what I know, one X-chromosome is ...
7
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2answers
12k views

Why doesn't the human skin grow back exactly how it was before being damaged?

Very simple: Why (and how) is regenerated skin different from original ? As we know we lose skin cells that becomes the dust in out homes and it always grows back to full thickness right ? So when I ...
7
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1answer
2k views

Alfred Jost's rabbit experiment: how did he actually do it?

I was watching a Crash Course on Biology YouTube video by Hank Green: Great Glands - Your Endocrine System. Hank humorously describes a sex determination experiment by Alfred Jost as follows (...
7
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1answer
2k views

Why is there no cure for Dandruff?

It looks like a simple problem, affecting almost half of the population at the post-pubertal age and of any gender and ethnicity [wikipedia]. What is so complex about finding a cure? Also, if you know ...
7
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1answer
888 views

Why do haemophillic females $X^hX^h$ die before birth?

I just came across a statement in my book , while reading genetics, that haemophiliac females do not survive till birth (the reason not mentioned here why) . Before posting this question here I ...
7
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1answer
7k views

Is ovum + ovum fertilization possible for human?

In humans is it possible to fertilize a ovum with another ovum from the same female subject? I already found some works in which the ovum is fertilized by a somatic cell (see e.g. this ), but I am ...
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5answers
4k views

Why do most animals never seem to evolve over millenia?

People often say, including those with extensive knowledge in biology, that a certain species of animal will evolve in one way or another: From changing environments. Mutations. Possibly even genetic ...