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Life from the perspective of colour blind people 

Deuteranomalia: This is caused by reduced sensitivity to green light. Deutan color vision deficiencies are by far the most common forms of color blindness. This subtype of red-green color blindness is found in about 6% of the male population, mostly in its mild form deuteranomaly.

Protanopia: Caused by a reduced sensitivity to red light due to either defective or a lack of long -wavelength cones (red cones). Some scientists estimate that being a protan is associated with a risk of a road accident equivalent to having a blood alcohol level of between 0.05 and 0.08 per cent.

Tritanopia:  People affected by tritan color blindness confuse blue with green and yellow with violet.  This is due to a defective short-wavelength cone (blue cone). Whilst  Protanopia and Deuteranomalia are significantly more common in men, tritanopia affects both sexes in equal amounts.

Monochromacy: Only around 0.00003% of the world’s population suffers from total color blindness, where everything is seen in black and white. 

4

In 2010, Sonia Vallabh watched her mom, Kamni Vallabh, die in a really horrible way.

First, her mom’s memory started to go, then she lost the ability to reason. Sonia says it was like watching someone get unplugged from the world. By the end, it was as if she was stuck between being awake and asleep. She was confused and uncomfortable all the time.

“Even when awake, was she fully or was she really? And when asleep, was she really asleep?” says Sonia.

The smart, warm, artistic Kamni – just 51 years old — was disappearing into profound dementia.

“I think until you’ve seen it, it’s hard to actually imagine what it is for a person to be alive and their body is moving around, but their brain is not there anymore,” says Eric Minikel, Sonia’s husband.

In less than a year, Sonia’s mom died.

An autopsy showed Kamni had died from something rare — a prion disease. Specifically, one called fatal familial insomnia because in some patients it steals the ability to fall asleep.

Basically, certain molecules had started clumping together in Kamni’s brain, killing her brain cells. It was all because of one tiny error in her DNA — an “A” where there was supposed to be a “G,” a single typo in a manuscript of 6 billion letters.

Sonia sent a sample of her own blood to a lab, where a test confirmed she inherited the same mutation. The finding threw the family into grief all over again.

Today, Sonia and her husband live and work in Cambridge, Mass., where they are both doctoral students in the lab of Stuart Schreiber, a Harvard professor of chemistry and chemical biology. Over the past several years, the couple has completely redirected their careers and their lives toward this single goal: to prevent prion disease from ever making Sonia sick.

A Couple’s Quest To Stop A Rare Disease Before It Takes One Of Them

Photos: Kayana Szymczak for NPR

tenderfacemeat  asked:

recently read about an english mastiff breeder in nsw who outcrossed their line with a greyhound, to controversy within breed circles. personally, no expert, but i think this is a great idea. do you have suggestions for how to find other breeders doing similar, or how dog lovers can encourage this sort of thing more generally -- especially in breeds with severely bottlenecked genetics like the english mastiff? (qt: came for the berner breed eval, stayed for everything else)

I think it’s a great idea, outcrossing to a breed to acquire a few desired characteristics and then breeding back to the target breed.

Dog breeders are likely to have a fit because the dogs in question are no longer ‘pure’.

Originally posted by avocadosalad2

Nobody cares, really, if a dog’s lines are ‘pure’ back to 100 generations. If somebody wants a purebred dog they just want a dog that looks and acts a certain way. The obsession with ‘purity’ in the dog breeding world is not based on science and frankly a little bit worrying.

Dogs are dogs. We should be breeding for health first, behavior and shape second. ‘Purity’ is such an unimportant and genetically meaningless concept.

There are so many breeds that could be improved by crossing to another breed with the desired trait every 5-10 generations. Here is a fairly famous example of crossing Corgis to Boxers in order to bring the genetic bobtail into boxers before docking was banned in the UK. Here are some of their photos.

Generation one:

Generation 2:

And Generation 5, winning prizes at shows.

There is, as expected, a bit of a huff with some boxer clubs that these bob-tailed boxers are not ‘true’ boxers. But as they continue to be bred to boxers for more and more generations, they really are. The only corgi-specific gene that is still selected for is the bob tail one, and these dogs are otherwise indistinguishable from ‘real’ boxers.

If we could do this targeting desirable health traits in breeds that are lacking them, we could improve the health of multiple breeds. This would require a major shift in current breed clubs, and breeder’s philosophy, and I unfortunately don’t know how to make this happen.

Do you ever think what would children of demigods be?

I mean, let’s say that the God-gene is dominant and shown with ‘R’ and mortal gene, which is recessive, is ‘r’. Then we can show the demigods with 'Rr’ right? Be patient, this will make sense soon. In Mendelian genetics, when you cross these two individuals (Rr x Rr), you will have a demigod (Rr) with 50% chance, a normal human (rr) with 25% and with 25% possibility A FREAKING GOD (RR). I mean, this is just a theory but ANNABETH MAY GIVE A BIRTH TO A FREAKING GOD. And can you imagine, he or she will have powers of ATHENA and POSEIDON. No, I cannot calm down. And, yes, I am a nerd.

So in my biology class today, while learning about genetics, our teacher had us doing this activity where we simulated the process of how a person ended up with the genes and traits that they do using the parents genes. We were supposed to draw an end result of what they would look like with the genes that they got, and we were told to draw the full body only wearing a diaper so we could see all the traits. But somehow i missed the memo that we were supposed to draw a baby, so I ended up turning in a drawing of a ripped 27 year old dude only wearing a diaper, and now it’s hanging on the wall next to all the baby drawings. This is going to be an interesting rest of the year…

everystarstorm  asked:

As a biologist the episode "The Zoo" really interested me. A much smaller population separated for thousands of years makes me really wonder how physically different the zoo humans are to earth humans. The zoo humans are even selectively bread. It's just something I've been thinking about since I saw that episode.

@everystarstorm said:
Also adding to the selective breeding thing I think that adds to how complacent they are. After all humans are inherently curious and questioning but the zoo humans just aren’t. Not to say the socializing part didn’t play a huge roll in it but not one of the humans ever questions anything in the zoo. That’s not something humans do, it’s even the plot of several movies.

That’s a really interesting observation. Physically, the Zoomans even subsist on a different diet. And yet, Steven and Greg eat the food easily. That’s Homeworld’s reverse-engineering organic food like fruits. 

And they’ve never felt physical pain. Like, everyone is barefoot and walking on the ground, but I doubt the ground has anything that can actually injure them. One thing that interests me about the selective breeding aspect, is that Homeworld probably has records of them. The selective breeding may be such that it maximises genetic diversity or minimises congenital defects. 

In fact, having a species so separated for so many years, it would be interesting to ask whether they were still considered “human beings” in the way we see ourselves. Their physical makeup may appear the same, but physiologically, they might have faster metabolisms (judging by the length of a “day” in the Zoo) and different base inclinations.

Taking it further, in another few centuries, they might be considered a new branch off the genetic tree. 

theatlantic.com
What If (Almost) Every Gene Affects (Almost) Everything?
Three Stanford scientists have proposed a provocative new way of thinking about genetic variants, and how they affect people’s bodies and health.
By Ed Yong

In summary: The notion that only a couple of relevant genes affecting one trait–like a handful of genes involved in, say, bone growth for height variations–may be falling into the bucket of old and rejected scientific hypotheses. Scientists are now finding data that support a newer hypotheses that there’s actually a network of genes–some even unrelated to the characteristic in study–that can affect a single trait or disease. For example, the scientists in this article talk about how they may have identified as much as 100,000 genetic variants that affect just height alone. Each of those variants may have a very small or even seemingly irrelevant affect on height, but the effect ripples and builds. 

Or, as a better metaphor from the article:

Put it this way: The Atlantic is produced by all of us who work here, but our lives are also affected by all the people we encounter—friends, roommates, partners, taxi drivers, passers-by etc. If you listed everyone who influences what happens at The Atlantic, even in small ways, all of those peripheral people would show up on the list. But almost none of them would tell you much about how we do journalism. They’re important, but also not actually that relevant. Pritchard thinks the same is true for our genes. 

Fascinating article and worth a read. If the hypothesis turns out to be true, then this is about to become a significant paradigm shift in biology.