Martian Evolution 

Imagine Martian ambassadors coming to Earth wearing masks and strengthening exoskeletons, or Eathling ambassadors visiting Mars with masks and radiation suits.

Ah, speciation. I'm happy they're finally covering this! Even much of science-fiction rarely touches this subject.

When aliens finally visit, they'll bring us cookies from "grandma" and tells us stories about our ancestors that sent the first group to earth.

But isn't there a decent chance that in amount of time it takes to develop such a significant changes between Martians and Earthlings, space travel between the planets would become affordable (like taking a plane today) thus eliminating the environment isolation and species differentiation in the first place? Hard to predict that, I know, but still..

Someone should make a movie about this. 2 species 2 planets, earth is dying, Martian humans don't want earth humans to come, battle for survival...

We need a Mars equivalent of Oregon Trail.

This show is amazing, for the first time ever I can grasp physics at a level I never thought possible without the maths I thought necessary to do so. Inspiring me to start my journey into higher levels math on the Khan Academy. I wish these resources were available when I was younger, it may have changed the course of my life. My 5 year old son watches your shows with me and is able to grasp higher level concepts at a very young age, which will most likely guide him in his future endeavours. So, thank you for the great show and thank you to the Patreon supporters who ensure the show's future so my son can learn and enjoy the unique perspective of the world that only comes with an in-depth knowledge of it.

"Having reached the forested fields of Oregon, your party dies of dysentery." ::cue melancholy chiptune::

Imagine racism between Earthlings and Martians

So humans on Mars will slowly evolve into Slenderman?

"...right before dying of dysentery." Woke up my wife laughing.

You guys should really watch, or read, The Expanse. It contains excellent, and scientifically accurate, portrayals of humans who evolved in very different , low-G environments like Mars and Ceres.

Just wanted to say I absolutely love all of the content that Space Time produces. Very entertaining and educational.

it's funny to think that we can go on holiday on mars in the future

It's been a while since I've had this. It's not bad. It's how I remember honestly

I want a documentary or TV series based on this! That sounds so cool!

2:10 "Matt made Tenure" mfaoooooooo

Just don't bring back any Xenomorphs.

I'd love to see an artist's rendering of this! Absolutely fascinating.

Darker on the surface and lily white under the ground? Sounds like a reversed Morlocks and Eloi lol

I have decided to Major in Astronomy. I'll be back to this video in 4 years.

what if there is no aliens, but eventually we become ALL of the aliens, by speciating on different planets.

"Musk guy" "Gone supernova" Some of the best quotes

Didnt find any comments about "The expanse" but i was thinking of this almost the whole video :)

two words: gene editing

Charizard will be a dragon type on Mars.

Congrats on getting tenure!

Martians could just be hairy to block the UV light. Martian Wookies. XD

BUT WHAT ABOUT MUTATIONS FOR VENUS!!!! Seriously, a Sci-fi book where humans have colonized Venus and Mars, with Earth and Venus being similar but Mars isolated and different would be amazing.

Wow, just in time for my dinner. Food for body AND for a brain!

I already imagine a war between the earth and the mars factions

Nice explanation of the basics of evolution: mutation plus selection pressure plus time.

There's a huge caveat to all this speculation. All evolution is dependent on selection, which is just a fancy way to say dying. A population will only adapt to an environment if those poorly-adapted individuals die off at greater rates than better-adapted individuals. Or really, even more to the point, if they die /before reproducing/ at greater rates. But our present attitude towards death is one of enabling even the least-fit of individuals to survive, and our technology for doing so is only getting better and better -- especially with things like CRISPR on the horizon. It would take a massive failure of that project for natural selection to even act on humans at all in the future, either on Earth or on Mars. If we can keep everybody alive at least long enough to have kids who we likewise keep alive, evolution has no chance to act. And over time our intent and ability to do that has only increased with no signs of stopping. There might still be artificial selection, or even a non-selective evolutionary process, with our advancing biotechnology. But in that case, a lot of the changes made to help the population of one planet would also be made to the population of the other because there's no reason not to. Need to engineer Martians to have stronger bones? Well, Earthlings could use stronger bones too even if we don't need them as much, so why not? Martian immunity genes growing weaker over the generations? Earthling immunity genes are still perfectly strong and we can splice those into the Martian population as needed. And so on. I think it's more likely that we end up with a genetically engineered immortal superhuman population on both planets, over evolutionary timescales, than that we see Earth and Mars populations allowed to speciate.

I must disagree with you here. Yes, it is very likely that speciation will occur when we colonize Mars and other planets in our solar system. But it isn't inevitable at that point just yet. Travel between a planet's surface and space is likely to become much easier in the coming decades and centuries. I think we will probably develop a full solar system wide civilization which could likely have near constant travel and communication between the planet based colonies and (more likely in the long run) our Dyson swarm of artificial habitats. Where speciation DOES become inevitable is when we go interstellar. Humanity (and it's descendants) is probably destined to expand across the galaxy in time. But there will be no galaxy-wide civilization. The limitations of the speed of light mean that colonies in neighboring solar systems are necessarily isolated from each other, and are by any reasonable definition two separate civilizations. The populations of those two colonies will inevitably diverge in their evolution and become two distinct species. Which means that the Star Trek image of a galaxy saturated with humanoid aliens might actually be more scientifically accurate than we ever thought (for the distant future).

I've been watching this show for over a year and it is awesome

It would be great to have another video on this subject in the future when more is known.

_"..Dark they were and Golden-eyed.."_

Someone got a little sunburned - you could have benefited from a mutation for more melanin. ;)

You guys should pay the guy who made this thumbnail more - it looks like something that would go on the start of a decent sci-fi show.

Man just as I go a month without talking thinking about us getting to Mars and how I could fit in all of that, you come out talking about the difference in microbes, made me feel my body pump and could feel the air being cleaned, things being excreted, cells being created and dieing e.g. Brilliant video, Thank you

The biggest genetic difference between Martian and Earthb population will come from the founder effect when selecting the first colonists. If we are going to be as selective as we are with astronauts now, Martians will be most intelligent, cooperative and fit group of humans. Probably for the better.

Last time I was this early, Super Saiyan 3 was relevant.

Congratulations to Dr. O'Dowd on his tenure.

Perhaps the first and only time I didn’t get lost in Space Time 😀

It's also possible that natural selection won't factor in at all. By the time we colonize Mars we may be ubiquitously employing genetic engineering

How pokemon will evolve on mars?

That dysentery gets everyone.

Reference to Oregon Trail? +9000 internet wins!

Thanks for the awesome channel

Great work in that video! Would have been interesting to discuss the effects of isolation on the mind and what possible adaptions of humans could be (both biological and in terms of building the cities on mars maybe).

That ending though, LOL! As for combatting the Martian fragility, one could just do specialized exercise 38% more frequently on Mars than you would on Earth.

Okay but that tenure joke was brilliant

One thing I'll never forget about science is that they thought the atom bomb would ignite all of the oxygen on earth. And. They. Dropped. It. Anyway.

The science described in this hypothetical scenario is awesome! However, I'd like to offer up an idea: that if we humans actually get to the technological point of colonizing Mars anytime soon, it is highly likely that we will have the technology and infrastructure to easily transit between the two planets, similar to taking a flight between two countries today. I think it would be likely that 'enough' people would be traveling back and forth (and subsequently procreating) between the two planets that would prevent isolation and the subsequent evolutionary split. Think about it. The two planets are only on the order of 10 light minutes away. Economies, culture, politics, and individual people etc, etc. of Earth and Mars are likely to be influential both ways if not intimately integrated. Whatever species ends up on Earth and on Mars will likely co-evolve together. I can envision this evolutionary divergence becoming more a reality perhaps once we become an interstellar species when communication and any meaningful interaction occurs on the order of 10's of years or more.

this is my favourite channel on youtube!

Oregon Trail reference in a video about Martians and their weirdness lol dayum I love this channel.

Imagine the olypics on Mars ( probably on the Olymp mountain) with 38% of Earths gravity, who knows how much easier would be to run 100 meters or jump high or even lifting weights. The statistics will be so different.There will be the world record and also mars record.

I freaking love science!!!

Man I am 15 and I love the way you explain this. Salute!

now I need to do a 23&Me test to find the source of my luxurious hair...

Aww, no interview with Elon... Great show anyway ;-)

wouldn't increased radiation select for better cell repair mechanisms

This is such an awesome problem to work through ! I can imagine a day when humans populate the solar system

As a specialist in the biological sciences (immunology), I appreciate an episode of PBS Space-Time that doesn't melt my brain ;)

PBS Space Time drinking game: Take a shot every time you hear a sound effect from Star Trek. Take a shot every time you fail to understand something. Take two shots every time you almost, but don't quite, understand something. Legal notice: This is the official, PBS-endorsed Space Time drinking game. It is definitely affiliated with PBS, and accurately reflects the opinions of their employees. PBS accepts full responsibility for any injuries, deaths, or universe ending SCP anomalies caused by playing this drinking game.

i've never understood why the hell you'd want to keep humans as close to being suited to live on Earth, if these colonists on Mars will absolutely never get back?

The last sentence made me smile

We never had tails! What is called the "tail bone" is actually the protective bone mass for the end of the spinal cord.

I have few problms with these predictions: 1. Genetic modifications in humans are ahead, so i belive that evolution will be more choice-based, and will probably result in huge variety of genome in both earth and mars. (just like ppl now get tatoos or plastic surgery, you could one day get genetical modifications just for fun/fasion/whatever reason) 2. Wont we bring some bacterial flora to mars with us? i mean not every ship will be sterile (earth bacteria would adapt much quicker than humans) 3. mixing population will occur, and i dont think it will be dimnishable. multiplanetary buissness trips, tourism, even if its expensive, there will be traffic.

Please comment on possibility and consequences of: Multidimensional Time

Oh Oregon Trail, such a fond childhood memory.

I can't stahp laughing... the Oregon joke... my tummy hurts, so funny!

Humans haven't speciated because we rapidly became a globe fairing species and all of a sudden we were interbreeding again. I'm not sure how long it typically takes to lose the ability to interbreed but we have some fairly different non cosmetic traits. I hope i don't sound racist or favoritist now but here we go. Honestly the largest example of evolutionary distinction to me as a Caucasian Canadian are people of African-American decent because: 1) their African heritage makes them more resilient to solar radiation than I am; 2) the horribly detestable action of artificially selecting humans for breeding during the slave trade has resulted in some black people who are A) freakishly tall and B) freakishly genetically predisposed to strength and stamina. (And I don't mean freakish in a hateful way, I'm jealous!) Furthermore there are distinct cosmetic facial and body features typical of different backgrounds which are interesting, and I wonder if they are all exclusively caused by genetic drift and prior isolation from other human populations (like when we first started to populate the continents), or if some generate important advantages. I'm not sure exactly on the timescale, but given that humans originated in Africa, the African people who are still in Africa, especially in more isolated communities today, have had longer than the rest of us to respond evolutionarily and genetically to their specific environmental pressures. They might literally be the "most evolved" of all the human racial archetypes or heritages or whatever you want to call someones background. It might only be slightly more evolved though, I know genetic evolution takes a long time. Thoughts anyone?

It's easier and more resource efficient to just make rotating habitats in the long run. One obvious benefit is that all planets will eventually die due to their parent star dying, but a rotating habitat you could quite easily move to another star system it doesn't even need to be sun like, and that is if a star isn't already simulated with artificial light source by the habitat itself. With fusion the whole human specie diverging thing would be unlikely since everything on the habitat could be made to mimic Earth, barren planets like mars would just be glorified resource mining fields.

This will make a great plot for a movie

1:20 "Characteristics genotypes", another key to evolution along with mutations and natural selection.

I wonder if part of terraforming should be to transfer earths biosphere to the new planet. Our immune system is pretty handy, I think it would be a mistake to risk weakening/losing it. This would also allow safer travel between the planets.

the universe is flat.

It's amazing how they always manage to make an ending line that ends with "Space Time"

you can tell matt down was at the beach with a pair of pitvipers on living his best life

Well, there is the story of the Argentinian Polar Dog, a dog breed specifically developed through artificial selection, that was created in the middle of the 20th century after Argentina set their first bases on Antartica, to help with the sleed and other works. After the stupid Antartic Treaty ban of dogs from the Antartica, the 60 remain dogs on the continent were moved to Argentina, and they all died during the next year since they had lost the inmunity to other dogs viruses ans bacterias, getting extint. I hope we don't see something similar with the Martians Humans.

Really interesting... I think that the first human engineering will be available legally to permit space exploration because that is a cause that can be recognized as morally justifiable for something that will probably rise many critics in the near future.

I love this channel even though I do not undestand anything sometimes.

This video gave me so many great ideas for movies and novels holy shit

Can you explain how a Mars colony would be affected by time dilation

You talk about a species that's optimized for low oxygen, high cancer tolerance? Have you heard of naked mole rats? Mars doesn't so fun anymore...

thanks for making the plot of The Expanse feasible :D

Now when I watch (the original) "Total Recall," I can't get these thoughts out of my mind.

is lunar colonization a plausible idea?

Comawn 3000 years? By then we'll have technology to freely move between planets in the Solar System on a whim. Anyone who would want to visit earth could do so at any time. Not to mention we'll have better gravity simulations and gene manipulation technologies at our disposal. So any body plan we want we can have. And if 2 people want to make a kid together I think we'll have the technology to make it happen no matter how far our "races" may drift. This video is not taking any of this into consideration.

"Evolution is blind". 👏 👏 👏 Great synthesis.

Its a pleasant surprise when a physicist can actually explain evolution. There is an amazing disparity in many public scientists understanding fields outside their own - and that doesn't help common folk get a clear idea... But no blame goes to you! I would say great episode but you're such a dependable host with ever interesting content, that all the episodes are equally delicious. Thank you!

I wonder if it'd be possible for humans to evolve out of sentience. Imagine a bunch of humanoid creatures with the intelligence level of a cow running around mars.

It would seem to me not only inevitable that each planet we colonize would produce different human species over time, but that we would want to use gene editing techniques like CRISPR on those we send in the first place. Sending ordinary earth humans to colonize mars seems irresponsibly dangerous to those colonists. It would be in the colony's best interest to use every technique we have to ensure their survival, including editing their genomes beforehand. Of course this would have moral consequences, since people edited this way wouldn't have a choice in the matter, they would have to be edited early in their development before they could verbally consent to such changes.

This was by far the best Space Time episode ever.

If Matt ever leaves PBS Spacetime, they should do it like a Doctor Who regeneration.

You think you're some kind of genius? Me: "homo" Science is one of the reasons why I don't have friends

when i watched ur last year videos your voice is very energitic but now some much lack of energy in your voice

Great episode, as always! (but I wanna return to GR! I beg for episode about Elle Cartan extension to GR!) A few cents from molecular biologist/bioinformatician... 1. Our colony on Mars will not be sterile, we WILL bring our own microbes with us whether we want it or not. This includes pathogens too, so the arms race would keep up. Also the significant bottleneck of actually getting to Mars would mean that we would carry only SOME pathogens with us - probably mostly opportunistic pathogens on our skin. So, I would bet the common cold or flu would not be so common there, if at all - but fungal skin infections or intestinal tract problems, hell yeah. 2. I wouldn't also count on the separation much, no to the point of speciation. If we get there once, we will get there again and again - maybe not often, but we will, just like with colonization of Americas in XVI-XVII century. 3. I think You didnt mention that Mars also gets much less sun than Earth, which probably factors towards lighter skin shades. 4. Xray resistance may not be as hard to get as some people think. While afaik not common in higher organisms, there are some bacteria which are insanely resistant to Xrays using many mechanisms. First, people forget that DNA is not alone, it is shielded by tons of different proteins, and all those proteins can evolve towards stabilizing it, if pressured. Second, I think You could try to evolve proteins which absorb the high energy em radiation and converts it to something else, probably just dissipating it as heat for starters - I hear stuff like that happens to some microbes living near the Tschernobyl (or however you spell that city in English, sorry, I am to lazy to check : P). Third: repair, repair and repair - but You mentioned that. 5. While it would seem that Martian soil can support some basic crops, I think it is safe to say that it wont support them all. Many plants which we take for granted may have SEVERE problems growing there, not only because of elemental composition (which we can control anyway) but because of soil bacteria. And no, we cannot just transplant bacteria from earth along with plants - for reasons which would take another post to merely touch. So, I think Martians might have to evolve to very strange and limited diet, they might be even forced to genetically engineer themselves to start producing some vitamins which we, on earth, do not have to produce.

Congrats on your tenure, Matt.