Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics.

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Why 22 amino acids instead of 64?

This question got me thinking about amino acids and the ambiguity in the genetic code. With 4 nucleotides in RNA and 3 per codon, there are 64 codons. However, these 64 codons only code for 22 ...
18
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1answer
464 views

Do trees age on a microscopic level?

Most animals age via at least two mechinisms: at a "macroscopic" level, basically wear and tear to the point where (on evolutionary time scales) it's more genetically advantageous to optimize for ...
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How many genes do we share with our mother?

Somewhere I have read we share more than 99% of our genes with every other other person and 98% of our genes with chimpanzees. What does this mean? Don't we share 50% of our genes with our mother and ...
14
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865 views

What is the smallest number of amino acids required for life?

Is there any hypothesis on the minimum number of amino acids required for life?
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2answers
4k views

What is the advantage of circular DNA in bacteria?

From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes? Do there exist bacteria with more than one ring of DNA?
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438 views

How does the modern theory of evolution solve these apparent problems? [closed]

I hold to the truth of Evolution, but I've encountered several problems with it, that I can't answer, and I can't find an answer for, despite much research. If would be great if anyone can answer ...
10
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3answers
511 views

Mathematical Modelling of Natural Selection

I'm a math undergrad looking for some papers on modelling the process of natural selection. The only paper I've been able to find is by the pre-eminent mathematician Herbert Wilf from 2010, There's ...
8
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2answers
2k views

What makes a gene dominant or recessive

We all carry two copies of each gene (outside of male sex chromosomes). If the two differ from each other often one is dominant and one recessive. How does this mechanism work on a molecular level? ...
23
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4answers
988 views

Why do men have nipples?

I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them? ...
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Can two humans with 44 chromosomes produce viable offspring?

It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes. One example is a male in China: the first article, the second article. The other is a female in ...
5
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2answers
125 views

Book recommendation on population/evolutionary genetics?

I have recently been involved in collaborations that require me to model the population genetics of eukaryotic populations. I fear I may either be "re-inventing the wheel" or making conceptual ...
17
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2answers
316 views

Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?

While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the SNP ...
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2answers
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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 ...
9
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1answer
89 views

Which patterns do I have to avoid when modifying the 3'-UTR?

I want to change a pre-miRNA sequence (in my case the pre-miRNA is encoding in a 3'UTR of a gene) and then put it in a lentivirus to see if it is still processed. After modification (permutation of ...
5
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3answers
249 views

Can extinct animals be cloned?

Scientists have found mammoth blood, and are planning to clone a mammoth. How does one go from having its blood to a full blown living mammoth? Is it possible? Why does it matter if the blood is ...
2
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2answers
183 views

Why is the strength of genetic drift inversely proportional to the population size?

I saw a concept on the Internet that says "the strength of genetic drift is inversely proportional to the population size". I don't know why they are inversely proportional? Can somebody explain? ...
2
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1answer
102 views

Do genes play a role in the athleticism and shape of a person?

I am an Indian with a small thin stature with some deposition of fat around my belly.I was wondering if genes play a role in fat deposition in the body for Indian, Chinese, European or African people. ...
1
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1answer
38 views

Is there a possibility that medicine will affect the efficiency of natural selection?

I mean, saving sick people means that they possibly can propagate something that nature does not allow. I know that there is already something that operate at genetical level producing alteration, ...
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1answer
74 views

Pedigree Diagram help

I am asked to fill the genotypes in the spaces provided but looks like I am aving a little bit of trouble. can anyone help? thanks in advance!
7
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1answer
216 views

On average how many genes / alleles do people share?

I am curious about how much more a child can be alike to one parent than the other. If a child were to inherit all the alleles that are shared between both parents from one parent, but inherit all ...
5
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1answer
78 views

Hill-Roberston effects and effective population size

From this article, first page, middle of the second column: Even if harmful alleles do not become fixed, they can still reduce the efficacy of selection on neighbouring loci through a process ...
5
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1answer
409 views

Smallest unit on which selection can act

Traditionally, the individual was considered to be the smallest unit on which Natural Selection (NS) acts. Today, we usually consider the gene as being the unit of NS. Of course, we should also ...
9
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1answer
208 views

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

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 ...
7
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1answer
138 views

Genetic Drift: Models, assumptions and empirical observations

There two main mathematical models to describe the process of genetic drift are Moran model and Wright-Fisher model. My questions concern the assumptions of these models, the existence of other ...
5
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3answers
2k views

Do apes and humans share 99% of DNA or 99% of genes? What is the difference?

I made an answer on the Scifi.SE that can be read here. It is about how the characters in the story Jurassic Park might have gotten DNA for all the species shown. In my answer, I said this: Apes ...
4
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2answers
652 views

Chromosome 2 fusion?

I read this article by Jeffrey Tomkins and Jerry Bergman claiming to debunk chromosome 2 fusion. Is there anything wrong with these conclusions? " 1.The reputed fusion site is located in a ...
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3answers
319 views

Athletes: nature vs. nurture?

Having watched a lot of olympians the last few weeks, I was struck by how many of them have actually spent their wholes lives/careers training for their one event (be in running a marathon, or ...
9
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1answer
156 views

How are new people created from the DNA of an aged person. i.e. Why are we young?

The question "why do we age" has been asked numerous times. But why are we young? The cells of the adult human being are an age (time>0), but how can old cells create new cells that are younger than ...
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1answer
76 views

Relative Property of Alleles

If there are three different alleles to a gene, is it possible that the first is dominant to the second, but recessive to the third?
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3answers
1k views

Why some genes are dominant to each other? What is the mechanism behind it?

If i have a brown eye gene which encodes the protein that is responsible for the brown color, and have a blue eye gene either, what is the reason that my eye color is brown? How does one gene ...
7
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1answer
314 views

How is the exogenous DNA protected from degradation during bacterial transformation?

During transformation, a bacterium can take up DNA from its environment. A small fraction of bacterial species are known to be naturally competent, meaning that they can engage in this sort of ...
6
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2answers
2k views

What determines if a gene is dominant or recessive?

Going back to my high school days we were taught about dominant and recessive genes. We were taught how to calculate the geneotype and pheneotype of potential offspring using a small table (forgotten ...
5
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2answers
132 views

How is gene expression estimated?

I'm reading this fantastic article on estimating body time: Molecular-timetable methods for detection of body time and rhythm disorders from single-time-point genome-wide expression profiles and one ...
0
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0answers
81 views

Genetic Linkage/Mapping question Help

Hello everybody! I need some help with this question in the image posted. As you can see in the instructions, I'm asked to map the genes. So the first thing I did is write out the alleles ...
8
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3answers
249 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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1answer
106 views

Why can't we breed watermelons without any remaining seeds in the flesh?

Watermelon is just starting to come in season in the northeastern U.S., and having a seedless watermelon is convenient. The only downside is, the "seedless" almost always still have the immature, ...
7
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1answer
93 views

obesity risk and single gene polymorphisms

I read a fairly recent meta-analysis of studies into the association between adult obesity and polymorphisms of the FTO gene (Peng et al., 2011). The paper looked at 59 studies and found that "FTO may ...
6
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2answers
128 views

Can any species be bred selectively/engineered to become as diverse looking as dogs?

I've done some research and it appears that dogs are the most diverse looking single species of mammals. The questions that interest me is - are dogs special in respect to genes/gene activation ...
5
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1answer
703 views

The genetic and physiological origins of laughter?

This Wikipedia article defines laughter in many terms, such as... "a visual expression of happiness, or an inward feeling of joy" and "a part of human behavior regulated by the brain, ...
5
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1answer
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What is the distinction between F' plasmid and R plasmid?

Is there a difference between an F' plasmid that has taken up a chromosomal gene that conveys antibiotic resistance, and an R plasmid? Is a bacterium containing an R plasmid and yet lacking an F+ ...
4
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3answers
970 views

Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
3
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2answers
151 views

Why and how does complexity usually tends to increase through time?

The question of complexity is classic in the very first lectures of evolutionary biology where the teacher usually tries to tell the students that complexity does not necessary increases and that ...
3
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1answer
131 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
3
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1answer
251 views

What hair color will result in someone inheriting both blond and ginger genes?

Both the genes for blond hair and ginger hair are recessive, so they need both parents to give the same gene for it to take affect. What happens when a person has 1 copy of a recessive gene and ...
3
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1answer
194 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
3
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3answers
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Evolutionarily speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
3
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4answers
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Can the third sex be categorized as Male or Female?

Hijra are people who have a penis (not sure if sexually active) but look much like a female (perhaps for some feminine biological property). Wikipedia says they are "physiological males who have ...
2
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1answer
68 views

Why are hybrids infertile?

Let's take a quote from Wikipedia about zebroids. Donkeys are closely related to zebras and both animals belong to the horse family. These zebra donkey hybrids are very rare. In South Africa, they ...
2
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1answer
42 views

List of heritability estimates in humans?

Many people on this site ask questions that directly or indirectly have to do with heritability in human. Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
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1answer
41 views

How usable is the Human Metabolic Model to predict biomass?

In order to use the Human Metabolic Model for Flux Balance Analysis of specific cancer cell lines, we would like to know what sort of flux values have been determined for the Human Metabolic Model. ...