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Why do men with dark hair sometimes possess a reddish beard?
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It has to do with a single gene! More than a decade ago, researchers discovered that one gene (MC1R) on chromosome 16 plays an important role in giving people red hair. MC1R task is to make the protein melanocortin 1. This protein plays an important role in converting red pigment into black pigment. If you end up with only one mutated MC1R gene, red hair can appear in unwanted places, like your beard. When someone inherits two mutated versions of the MC1R-gene (one from each parent), less red pigment is converted into black pigment. ...
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14851 |
duddy |
8 years ago |
Why do archaeologists and geneticists reach different conclusions?
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An archaeologists is a scientist who studies human history by discovering and examining human remains and artifacts. The most common image of an archaeologists is someone on their hand and knees digging through dirt, carefully using a brush to dust off an artifact from the distant past. A geneticist, on the other hand, is someone who specializes in the science of genetics. This field of biology deals with the pattern of inheritance, molecular structure and function of genes, and gene behavior in context of a cell or organism. Both professionals are highly skilled, and use the same basic principles of science to test hypotheses, gather data, and make conclusions. However, why do archaeologists and geneticists sometimes reach different conclu ...
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16262 |
bio_man |
2 years ago |
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4959 |
duddy |
10 years ago |
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6575 |
duddy |
9 years ago |
This synthetic organism survives with less than 500 genes
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This week in Science, researchers led by genome sequencing pioneer Craig Venter report engineering a bacterium to have the smallest genome - and the fewest genes - of any freely living organism. Known as Syn 3.0, the new organism has a genome whittled down to the bare essentials needed to survive and reproduce, just 473 genes. However, the function of 149 of Syn 3.0's 473 genes remain unknown. As Syn 3.0's name suggests, it’s not the first synthetic life made by Venter. In 2010, Venter's team reported that they had synthesized the sole chromosome of Mycoplasma mycoides - a bacterium with a relatively small genome - and transplanted it into a separate mycoplasma called M. capricolum, from which they had previously extracted the DNA. After s ...
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10768 |
duddy |
8 years ago |
This rare genetic condition causes an unusual pigmentation
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With a rare genetic condition called erythrism some insects, like this fluorescent pink katydid, develop an unusual reddish pigmentation. It's not enhanced in any way. The coloration ( erythrism) is an adaptation sometimes found among katydids exposed to red or pink foliage, although this one was in the woods off the Appalachian Trail near Mount Peter, N.Y. ...
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2020 |
duddy |
8 years ago |
This plant has the largest genome of all living organisms
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When it comes to genome size, a rare Japanese flower, called Paris japonica, is the current heavyweight champ, with 50 times more DNA than humans. It is a slow growing perennial that sports a rare, showy white star-like flower above a single whorl of about eight stem leaves. The exceptionally large genome of P. japonica is due to the fact that it's an octoploid, meaning it has four sets of chromosomes - on the contrary, humans are diploid (two sets). Its 40 chromosomes consist of 150 billion base pairs of DNA per cell, therefore making its genome the largest known genome of any living organism. In fact, the DNA from a single cell could theoretically stretch out to be longer than 300 feet (91 m). ...
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6460 |
duddy |
8 years ago |
Think you're having a bad hair day, check this out
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Uncombable hair syndrome, also known as Pili trianguli et canaliculi, is a rare structural anomaly of the hair with a variable degree of effect. It was first reported in the early 20 th century and was described in the 1970s. It becomes apparent from as little as 3 months to up to 12 years. The hair is normal in quantity and is usually silvery-blond or straw-colored. It is disorderly, it stands out from the scalp, and cannot be combed flat. The underlying structural anomaly is longitudinal grooving of the hair shaft, which appears triangular in cross section. There usually is no family history, though the characteristic hair shaft anomaly can be demonstrated in asymptomatic family members by scanning electron microscopy. To be noticeable, 50% ...
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4495 |
duddy |
10 years ago |
The truth about redheads
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Did you know red-heads have an evolutionary advantage in cloudy regions of the world, and they have a lower tolerance for pain than the rest of us?
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94145 |
duddy |
9 years ago |
Stress-activated gray hair explained
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An unexpected link in mice has been found between gray hair, the transcription factor MITF, and the innate immune in a recent study published in PLOS Biology. First, a discussion on the innate immune system: The innate immune system is the immune system you're born with. This includes your skin and other barriers which prevent disease entering the body, in addition to specialized cells that activate inflammation in response to foreign invaders. Technically, every cell in your body except for red blood cells, are capable of generating an immune response, and this includes the production of a signaling protein known as interferon. Microphthalmia-associated transcription factor (MITF) is best known for its role in regulating the many functions ...
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2400 |
bio_man |
5 years ago |
See the world's tallest man
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Kösen's height was caused by the production of too much growth hormone due to a tumour in his pituitary gland. The tumour was eventually removed in 2010 through revolutionary gamma-knife surgery. Amge has a form of dwarfism, caused by a mutation in a bone growth gene.
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5914 |
duddy |
9 years ago |
Schizophrenia may boil down to a specific gene, scientists find
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A landmark study, based on genetic analysis of nearly 65,000 people, has revealed that a person's risk of schizophrenia is increased if they inherit specific variants in a gene related to "synaptic pruning" - the elimination of connections between neurons. The findings represent the first time that the origin of this devastating psychiatric disease has been causally linked to specific gene variants and a biological process. They also help explain decades-old observations: synaptic pruning is particularly active during adolescence, which is the typical period of onset for schizophrenia symptoms, and brains of schizophrenic patients tend to show fewer connections between neurons. The gene, called component 4 (C4), plays a well-known role in t ...
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4496 |
bio_man |
8 years ago |
Is handedness determined by genetics?
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Approximately 10% of the world population is left-handed. What causes this anomaly?While there are several theories that try to explain this trait -- such as the positioning of the baby during the final trimester, hormone exposure during pregnancy, or epigenetic factors -- the most consistent and hardwired explanation boils down to plain old genetics. In other words, the reason you're right-handed or left-handed is because it's written in your DNA. Research suggests that handedness displays a complex inheritance pattern. For example, if both parents of a child are left-handed, there is a 26% chance of that child being left-handed. A large study of twins from 25,732 families also indicated that the heritability of handedness is roughly 24%. T ...
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5500 |
bio_man |
6 years ago |
If you thought being left-handed was odd, read this
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A rare condition, known as situs inversus, is when a person has their major organs mirrored from their normal positions. So, for example, the heart would be on the right side of the body, or the liver and gall bladder are on the left side. It is a congenital condition (meaning it's tied to your genetics) that affects 1 in 20,000 people - including Spanish-born singer Enrique Iglesias. Situs inversus is generally an autosomal recessive genetic condition, although it can be X-linked or found in identical "mirror image" twins. ...
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25448 |
duddy |
8 years ago |
How Selective Breeding is Used in Behavioral Genetics
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One of the methods used by behavioral geneticists is selective breeding. Selective breeding often involves selecting animals that are very different on one measure of behavior. For instance, if scientists take 20 rats and test how quickly they can solve a maze, chances are that they will get some variability in the speed with which the rats can solve the maze. Scientists would take the two fastest animals and the two slowest animals and breed them together. They would continue to do this over 20 generations, until they had a group of animals that solved the maze very rapidly and a group of animals that solved the maze very slowly. They are then able to examine potential differences in their brains and behaviors that contribute to maze solvi ...
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666 |
bio_man |
A year ago |
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