Hot answers tagged

23

Barring mental degradation such as Alzheimer disease, the old version will always recognize the younger from the memories they have from when they were young. But the opposite is not necessarily true. We all keep an idealized version of ourselves in our mind, which is forever young and clean and strong. The rigors of daily life rarely touch this interior ...


11

Appearance is pretty malleable As a good example, let's take identical twins. Now, identical twins generally look the same but there are differences between them which are obvious to anyone looking. Now the question is - why is that? And the answer is simple: phenotype, that is the physical expression of genes doesn't always match genotype, the genes ...


6

Circumstances are different for the young and the old. https://www.demilked.com/women-makeovers-yevgeny-zhuk/ I am always blown away by these striking makeovers. Now imagine a makeover decades in the making. Your old person grew up in the country. She worked hard. She had bad acne because there was not much to do about it, and she carried the scars. ...


6

The simplest answer is to pick a population growth rate and apply the Rule of 72 in reverse. Modern (industrial) societies seem to be running about 3%, which means every 24 (72÷3) years you go back, you halve the population. If you have 36M people in 2020, that means 18M in 1996, 9M in 1972, 4.5M in 1948, and so on until you reach ~550 people way back in ...


5

Ownership requires a framework of laws, agreed by all parties The term 'ownership' indicates a general accepted agreement that people (which also need to be defined) has some form of rights (which need to be defined) over items, objects and land (again, all of which need to be defined). The key though is agreement: without consensus you would not be able ...


5

We have 50.000 humans. All of them are supposed to be healthy on earth. Now, they land on the superplanet. The planet has about 3 times the mass to earth to get 3 times the gravitational pull. Mass is proportional to Volume, so Volume is almost factor 3. That gives $V_P=3 V_E=3\times 4/3 \pi \times r_E^3=4/3\pi\times r_P^3$ which can be simplified into $r_P=...


4

It depends on your definition of "cannot breed". If it is completely impossible to have a hybrid (like human and chimps) - then no. It needs a statistical miracle or genetic engineering to make it happen. If species can have a hybrid, but it is infertile - then (partially) yes it is theoretically possible. For example, mules are infertile, but there are ...


4

Our looks change a lot as we age. My grandfather once showed me some pictures of himself when he was aged 10-25 and my first reaction was "Hey, that's my cousin". And it really did look like my cousin; he was practically a clone of my grandfather at the same age. Even so, I had never before thought they looked anything alike despite meeting both at the same ...


4

Perhaps the first group found a difficult path to an inaccessible area where the trees grew. Sometime later circumstances changed so that the path was no longer accessible so there would no longer be anyway for the second group to reach the trees. The later change in circumstances could be a number of things for example A very difficult mountain pass might ...


4

If you have to use echolocation, you cannot afford solid surfaces blocking your line of sight. This means forget about glass windows if you want to perceive the outside of your vehicle. First cars and airplanes had their driver/pilot exposed to the outer environment, thus there would be no issue for those heroic gentlemen. But as soon as they want some ...


3

First, you can't evolve in regards to a predator you have no contact with for millenia. It's just not how evolution works. Second, any counter evolution from humans, would be driven relative to how the predator counters human "superiority". Is it killer Sharks, vampires, bacteria or something entirely else. Each would lead to a separate evolutionary ...


3

They are geographically separated. Vertically. Your tree people never come down to the forest floor except by accident or when they die. It is dark down there, and wet. There is quicksand. And there are monsters. The tree people know what is down there because they hunt for the things further down with things like fishing rods. The tree people do not ...


3

Facial processing ability varies a lot. So long as the character isn't deducing family relationships from similar appearances or recognizing people after decades apart, there's no reason to suspect he'd be able to identify himself aged 60 years.


2

Yes, it is possible. There is a known event where two separate specialized species of fish inhabited some African lake, one was pelagic and other benthic, they did not cross-bred due to pre-zygotal isolation (not trying to mate each other even if biologically capable). But then, pollution to the lake led to disruption of their habitat, and they merged into ...


2

Since you’ve stated that everything would be done by craftsmen at the local level, you need to look at what was valued in the preindustrial world. The answer is that food will be the absolute top priority, followed by weapons, followed by tools, followed by alcohol, medicine and everything else after. Scavenged supplies just wouldn’t last long enough for ...


2

A lot would depend on expectations. If the clone knows they are a clone, and wonder constantly about who their original is, they stand a much better chance of spotting them. There are even apps that can take their photo and make it look older. Not accurately, but might still give them an idea of what to look for. On the other hand, if all they know is ...


2

The circumstances in which this would happen are called normal circumstances. Kind of unusual for a query in this forum! Consider: The clone is not a 100% duplicate -- much more like a twin sibling Neither twins nor clones have identical appearances or personalities: the young clone is an entirely new individual with entirely different perspectives, ...


2

I doubt 12,000 years would mean significant enough evolution for both groups to be different species (unable to breed with each other), but it is posible, specially if the way of life in that place is very different to the one we know. The element I think would make the second group not be able to adapt, like the first one did, is competition. If the second ...


1

Colony population growth is different from country, or the whole continent population growth. On one hand, colony may have a plenty of arable land and untapped natural resources (which a settled nation doesn't have), which can lead to population boom. On the other hand, it is particularly vulnerable to diseases and crop failures. The famous Mayflower ...


1

It is important to be very clear about the definition of the word species in this question. Many definitions count separated groups of animals that have evolved different characteristics (and either do not meet each other or do not choose to breed if they do) as different species for example polar bears and brown bears, however by other definitions polar ...


1

Here are the selective pressures that could drive evolution. Assuming the givens of the questions: 1: predator comes. 2: predator drives humans into hiding. 3: while in hiding humans evolve. 4: humans emerge. How would they have evolved? From point 2: you select for humans able to hide. Humans inclined to stand their ground and fight, or humans which ...


1

I like the geographic solutions mentioned above. The first and second groups separated by a body of water or a collapsed cavern/mountain passage sounds entirely plausable and for me would require no further explanation. But for the sake of spitballing ideas... A totally different option may be based in unseen reasons. One or both may live in fear of mingling ...


1

The early fliers would not use any windows in their planes so they would have an unrestricted echo location “view”. These planes would probably not fly very high as they would want to be able to echo locate the ground and landscape. Before long instruments would be developed that gave them an artificial horizon, altimeter, air speed indicator and compass. ...


Only top voted, non community-wiki answers of a minimum length are eligible