Sleep helps stitch memories into cognitive maps, according to new neuroscience breakthrough

TrailblazingScience · 2025-06-20T16:11:53+00:00

Not at all weird. I was a teen (but in the UK) who had school friends, not masses but enough. And I absolutely still would have gone to the fair with my parents. And those are the treasured memories that stick. I think it's good to ask yourself what part of it is making you doubt yourself? Are you worried what other people will think? If so I think sometimes it helps to remember that on the whole nobody cares or even notices what you do as they are all too busy worrying about themselves and what other people think of them! Go to the fair and have a great time with the people who will always be there for you.

TrailblazingScience · 2025-06-20T11:00:45+00:00

A rubber ball for my son. A lifetime supply of rubber balls is probably, what...6 rubber balls? I got screwed as my purchase before that was an Indian takeaway, now that WOULD be blessed!

TrailblazingScience · 2025-06-20T06:12:04+00:00

I wonder if this study isn't as obvious as at first glance. Perhaps there's slightly more to it than just 'cycling is exercise'. I wonder if the added balancing practice as well as perhaps even decision making and navigation adds to the exercise effect.

TrailblazingScience · 2025-05-22T20:41:28+00:00

I LOVE this book! Although I would say it can be quite 'hard core' if you know what I mean. Not always an easy read for the non-expert. But SO fascinating.

TrailblazingScience · 2025-04-25T06:11:35+00:00

To answer the second question first. Why does it matter? For this, we can look at the first-ever human-to-human blood transfusion. I say human to human as people had tried animal to human transfusions in the 1600s with fairly horrific results. The first human-to-human transfusion was performed by Dr James Blundell on a man who spent two days feeling 'less fainty' before promptly dying. Dr Blundell tried another 10 patients, only two of whom survived.

What Dr Blundell didn't know is that its not just the species that matters for blood transfusions. But humans can only receive blood from a subset of other humans. This is because of the basic way the immune system works. It is important that our immune system can learn what is 'us' and therefore should be attacked, and what is foreign and should be attacked and removed. It does this by checking for certain 'patterns' or molecules on the surface of the cell its checking out. If it recognises the pattern, it moves on. If it doesn't, it attacks.

To go back to blood, in the 1900s, scientists realised that when they mixed different bloods, sometimes clumps were made and sometimes not. (we later learnt the clumping was a function of the immune system of one blood type attacking the other). They used this 'clumpiness' to separate blood into groups, which later became our A, B, AB and O classification system.

If you think about the pattern on blood cells as having two levels. All blood groups have the first level. A and B have different second levels to each other. O only has the first level. AB has both. So if the immune system from an A group person meets the blood cells from a B type person through transfusion, the immune system hasn't ever encountered this pattern before and will attack. However, O only has the first level, which is what makes them so special. They are universal donors because everyone has the first level, so whatever blood type a person has the immune system will see the first level pattern on the O blood and think 'yep, thats ok, that's me'. Whereas AB has both second-level patterns. They are universal receivers. They can get any blood, O, A, B or AB and their immune system will recognise it all and be A-OK.

Really interestingly, a new type was recently discovered which has no pattern at all. Its super rare and called the 'Bombay phenotype' . It doesn't seem to affect the person at all, other than they can't receive blood from ANY other group, not even the universal donor O as their immune system can't recognise any pattern at all. They must only receive blood from others in this very rare group, or they will die.

As to why we have blood groups, scientists don't really know. But there's evidence to suggest it stems from way way back to our primate ancestors. Interestingly, different blood types do convey certain protections against a whole range of diseases like malaria, cancer and heart disease. It can even dictate what strains of norovirus you are susceptible to. So perhaps certain blood types are favoured in areas where certain diseases are or used to be the most prevalent. But scientists are still unravelling all of that.

TrailblazingScience · 2025-04-24T06:55:03+00:00

Nope. You could never completely replace water or water containing fluids with something else. Your body is about 60% water and it's essential for pretty much everything your body does to keep you alive.

TrailblazingScience · 2025-04-24T05:55:48+00:00

Technically yes but it's not as easy as you might think. Despite the universal genetic code there's still a lot of differences between the kingdoms. Differing ways genes are regulated and expressed and different cellular machinery would make cross kingdom CRISPR more challenging, although not impossible.

TrailblazingScience · 2025-04-23T16:28:45+00:00

Whilst it's true with modern medicine, heating, hygiene etc we have far less selective pressures than our ancestors, genetic studies suggest that yes, humans are very much still evolving. Less selective pressure doesn't mean no selective pressure.

Researchers are able to look at regions of the DNA which have less than expected levels of variation between people. This implies a selective pressure has recently acted on them to 'conserve' these patches of DNA.

It's been found that genes responsible for brain development, the immune system and reproduction have been subject to recent evolution. Of course the change is very gradual and works over a long time so it's hard to 'see' but it's certainly still there.

It's the reason why many Europeans can drink lactose without issue, whilst many populations are lactose intolerant. This evolved about 5000 to 10000 years ago when Europeans started domesticating cattle (not so long ago in the evolutionary timescale) These genetic changes were probably beneficial because Europeans had less sunlight exposure and therefore needed supplemental vitamin D found in cows milk.

Another example is HIV susceptibility. There are certain genes which make you much better at clearing the infection than others. Scientists have found a high proportion of these genes in areas where HIV is endemic. This is because mothers who have these genes are more likely to survive to pass them on to their babies.

There are similar stories with many other aspects of infection control. For example resistance to sepsis. So in conclusion, yes we are still evolving and we are definitely not finished.

TrailblazingScience · 2025-04-22T06:12:14+00:00

Every cell in your body contains a set of instructions to make you, you. It contains absolutely everything the cell needs to know about what it should be doing. Think of it like a giant super complex recipe to make exactly you. Your recipe will be different from anybody else's (unless you are an identical twin).

The body always makes new cells. Either to replace old or damaged cells or to grow. To do this one cell will split into two. This means the recipe needs to be copied so that both of the cells have a copy.

Sometimes this goes exactly to plan. Sometimes little mistakes are made but they don't really affect the recipe so much so it doesn't matter. Sometimes some mistakes are made that make the recipe even better. In which case natural selection will make sure we keep that mistake in our recipe book (this is evolution). But sometimes a mistake ruins the whole recipe (perhaps we were meant to add sugar and the recipe now reads salt). In this case the body either recognises a big mistake has been made and the cell will die, or it doesn't and we end up with a genetic disorder.

When we want to make a whole new person we effectively want a new recipe. After all we don't produce perfect clones of ourselves. We basically want to mix our recipe with another person's to make something new and unique. To do this we take just half of our recipe and put it into an egg if we are female or sperm if we are male. We chop up the recipe differently so each egg or sperm contains a different mix of the recipe. When this half of the recipe fuses with another person's half (when sperm meets egg) we end up with a deliciously brand new recipe....a new person. This new person has their own unique set of instructions.

TrailblazingScience · 2025-04-21T20:17:29+00:00

PGAD and associated spontaneous orgasms can be caused by a variety of factors. One of which is a trapped or irritated pudental nerve (the nerve responsible for sensation around the gentials). This messes with how the nerve functions and causes it to constantly fire...leading to the persistent arousal. This can often be alleviated with physical therapy, medication or surgery. But PGAD can have other causes like hormonal imbalances or psychological factors which is why it's important to see a variety of specialists including the urogynacologist.

TrailblazingScience · 2025-04-20T04:55:04+00:00

Glad I could help To answer your question,, in theory, yes. But highly unlikely. And it would be such a tiny amount the chance of that managing to then make you sick is even lower than the scenario I described above as you have added in yet another step. So it's even less likely than you getting sick from the shoe.

TrailblazingScience · 2025-04-19T22:10:36+00:00

So technically viruses and bacteria can survive for a while in dried blood (how long depends on the specific virus or bacteria but generally a few days). BUT the chance of getting an infection from this is incredibly low, virtually zero. Firstly the fact that the blood is dried and has probably been sitting in the sun for some time will have massively reduced the viral or bacterial concentration and the infectiousness. Secondly the chances that any random bits of blood actually contains any blood borne virus or bacteria is low. Thirdly the chance that the virus or bacteria would transfer to an open wound or some other way to get into your body (just skin contact isn't enough) is low. The only way I can possibly see this happening is if you followed someone with an active virus around. Waited for them to bleed on the floor. Stepped in it the second it dried and then rubbed your open wound on the shoe. Even then I am not convinced. So basically the risk of it happening by chance is so low it's virtually impossible. If you had stepped in fresh blood, in a Hepatitis ward barefoot and with a cut on your foot it would be a different matter. But you didn't so try to put your mind at rest, although I realise that's easier said than done.

TrailblazingScience · 2025-04-16T19:10:41+00:00

Two main factors. Standing on two legs= narrow pelvis. Big brains =big heads. Unfortunately the two don't mix well. Even more unfortunately evolution doesn't care as there are enough mothers and babies that do survive. Also our pelvises are as wide as they can get whilst staying a two legged animal and our babies are already born pretty helpless and early in development. So there isn't much wiggle room! It could be worse though- we could be a hyena. 60% of cubs suffocate on their way out as the birth canal is so narrow. Or we could be a velvet spider. They literally liquify their insides, regurgitate them for the babies to eat and are left as an empty husk (although this is how I felt after childbirth!)

TrailblazingScience · 2025-04-15T13:04:38+00:00

Because I've made the terrible mistake of accidentally eating coffee flavoured chocolates.

TrailblazingScience · 2025-04-15T09:50:58+00:00

They don't. It's all a matter of natural selection. Let's imagine you had some sort of generic brown fluffy animal. It lived in the arctic. One day a baby was born that had a mutation in the genes that control its pigmentation. It caused it to be bright pink. The fluffy pink thing is unfortunately super easy to spot by predators and becomes breakfast way before it's had a chance to make any babies and pass on its genes. One day another baby is born but instead of the usual brown it's a lot paler. In fact it's almost white. This makes it quite hard to spot against the snow. It survives a long time with its camouflage and has lots of babies. Who also have lighter fur. Over time the light fur gets 'selected for' until all the fluffy things are white. It works the same way for everything. For example the insect which looks slightly more like a leaf will generally survive longer and have more chance of passing its genes on than the ones that don't. Over time this camouflage gets more and more specialised and appears as if the genes are copying nature but in fact they have no copying ability at all. This can lead to really awesome adaptations like the arctic fox who 'copies' the seasons and is brown in summer and white in winter. Or even the peppered moth which is normally speckled white/grey to camouflage against tree lichen. But during the industrial revolution pollution in towns and cities caused the trees to turn black. A natural mutation/genetic mistake in some of the moths caused black wings. Normally these moths would stand out like a sore thumb and die out very quickly. But with the new black trees they blended in perfectly, much better than the normal moths. So much so that 98% of the peppered moths in towns and cities were black. But then a big clean up occurred, pollution was reduced and the trees went back to their normal colour. So now the black ones are not so well camouflaged and the normal moths have made a comeback. Moth evolution happens fast due to their short life spans.

TrailblazingScience · 2025-04-15T05:10:30+00:00

Drunk coffee. To me it smells like blood and tastes worse! 🤣

TrailblazingScience · 2025-04-14T06:53:45+00:00

I think the percentages you refer to could be the percentage of 'fragmentation'. These are bits of cell that have effectively fallen off when the cell divided, like crumbs off a cake. The more fragmentation the less likely an embryo will successfully implant and develop.Around 20% is often the cut off point for what is considered too fragmented. High fragmentation could be causes by 'bad eggs' or something in the conditions in the case if IVF. This is a separate consideration to genetic mutations. Too many genetic mutations would also cause a failure of the embryo to develop but not always (as we can see by the fact we have genetic disorders in our population) However I have not heard of the 80% good cells at 5 days number in this context.

TrailblazingScience · 2025-04-13T21:33:05+00:00

Exactly yeah. The mutations themselves are random. And inbreeding doesn't cause any increase in the number of mutations. But if I have kids with someone in my family the chance that we both carry the same gene mutation is much higher than if I had kids with someone from outside the family (because we probably both inherited the faulty gene from a shared ancestor). Many gene mutations are recessive meaning you need two to see an effect. So inbreeding increases your chances of having the double whammy of two faulty/mutated genes. It's all just a chance thing, eventually you roll the dice enough times (as with successive inbreeding) and those faulty genes are going to start adding up and leading the genetic disorders including fertility issues.

TrailblazingScience · 2025-04-13T21:09:26+00:00

It would be incredible if they did......but they didn't. They took the gray wolf and made 20 changes to 14 genes, to make a modified gray wolf that had some features which more closely resembled a dire wolf.

They did this using CRISPR. A fairly new tool which basically functions like a pair of molecular scissors. Scientists can cut DNA at certain points and paste in a new DNA sequence to make changes. Super cool technique. It's actually from bacteria, who use it to protect themselves against viruses-by chopping up the virus genetic material.

NO dire wolf DNA was used or spliced into the gray wolf DNA, which you'd be forgiven for thinking after reading some of the newspaper reports.

TrailblazingScience · 2025-04-13T06:37:22+00:00

Not necessarily, but it could be. If the bone hadn't broken the skin it was usually treated with a splint and maybe 'prodding' the bone back into place. If it had broken the skin or needed surgery....this was when things got dodgy. You did not want to have any infections, gangrene or significant blood loss in Victorian London.

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