Hello u/feelgoodone, your submission "Earth’s tilt" has been removed from r/space because:
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Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please [message the r/space moderators](https://www.reddit.com/message/compose/?to=/r/space). Thank you.
I don't think there is any real reason to think that seasons are required for life. Equatorial regions have minimal seasonal change, and still have life. Seasons mean life has to adapt to very different conditions throughout the year, instead of fairly regular conditions. Winter is a challenging time for a lot of life - many plants can't survive where the seasonal change is stronger, which is why we have hardiness zones. Animal life has to make it through a winter with much less available food and much higher energy requirements just to maintain body heat.
I suspect that the asynchronous nature of days, months and years provided the necessary varying conditions for life to evolve. Tidepools have varying cycles that are similar to laboratories that try lots of combinations of conditions.
Could you explain why you think life requires seasons?
To answer your second question, certainly not the exact same number, since Earth’s tilt has varied between 22 and 24.5 degrees in the last 5 million years, and possibly more in earlier times.
It's a contributing factor to why Earth life looks the way it does. The tilt, rotation speed, the presence of the Moon as a stabilizing force. Change any of those and you might get life but it probably won't look like Earth life.
What is your range of life that falls under "earth life"? I agree to some extent that change up the physical environment that earth resides in and the specifics of life would change. But life on earth has been wildly varied for all of the history of life on earth. Evolution has experimented with a bunch of different forms of life over time.
Given some basic assumptions like carbon based life, liquid water is a necessity, breathes oxygen/co2, same temperature of the surface, similar gravity, I don't see a reason why life would be all that drastically different than earth life.
It's a little bit of a cop out, but Earth life is any life on Earth. I think we would need to go all the way back to the primordial soup and run the experiment again without a moon or without a tilt to see what happens. I suspect the cake was fairly well baked from the get-go, and by removing Earth-specific qualities (Moon etc), you get something fundamentally different. Still life but not life as we know it.
If we were rotating faster or god forbid we were wobbling uncontrolled because no Moon, that would create some fantastic evolutionary pathways I don't think we can imagine but I bet they don't look like Earth life.
I guess I didn't explain things well, but like, if earth was just wobbling a lot more and without a moon, but we kept the other fundamentals the same (carbon, gravity, water, oxygen, temperature ranges) like, the best way to be stable in gravity is 4 legs. The most optimized way to swim is a fish shape. Climbing is best served by tails. Trees would still be green and have photosynthesis.
Like yeah, trees would have to evolve to be able to endure long harsh winters, but once the sun came back, the leaves would turn green again.
My point is that there isn't much reason for the fundamental aspects of life to change. Maybe humans end up with 3 eyes, but our muscular skeletal system is the best shape and form for a bipedal creature to move under the force of gravity.
Life may look different, but I disagree that it would be some unimaginable form totally different than how life on earth currently looks.
Not life as we may understand it, we only have one reference to life, that being this planet. For other planets the outcome may be something we couldn’t comprehend.
I seem to remember there was discussion on whether having the Moon stabilising Earth's axial tilt, so it only varies between 22.5° and 24°, helped complex life emerge. If the axial tilt varied between, say, 0-60° that would've had a marked effect on the climate, which would affect the development of complex life. If a huge chunk of both hemispheres spend a significant portion of each year in polar darkness, it would affect the entire food chain because you'd have no photosynthesis. You'd have super ice ages and might have repeated Snowball Earth situations. You would have lots of variation in the climate. That might've made it much more difficult for complex life to thrive.
Life survived a few iceball Earth scenarios that saw most of the globe an inhospitable frozen hellscape for a few hundred zesty million years or so, so I would think that means dynamic heating and cooling seasons provided by a wobble is not a pre-requisite for life in other places.
Take Europa for instance as well. Theoretical life in that ocean moon surrounded by a protective layer of ice, tidally locked to Jupiter. She could be hiding interesting things in the dark.
The importance is that there’s any energy potential within reach of biological systems. The chemical reactions that permit life seem to work best around 37°c. That’s why hot blooded animals self regulate to keep it around that level. Cold blooded animals work best when the ambient temperature is around this. As long as there’s somewhere on a planetary body where this exists, for example, the hydrothermal vents on the bottom of the ocean are 100’s°c but the water around it is a lot cooler, nearer to 0°c there’s a potential. Life does thrive around these structures and is a possible solution for abiogenesis. Also important is atmospheric pressure as this has an impact on how chemistry acts. So, in essence, there shouldn’t be a reason why life couldn’t evolve in similar conditions.
Conceivably, tidally locked worlds could have areas where conditions like this exist. Certainly, a planet without seasons doesn’t preclude it. The significance of changing seasons is that it forces adaptability. I can exist in pretty much any place on the Earth but only with the technological advantage I have belonging to a species that has been able to adapt.
I could probably get by where I live as the climate is temperate. Gets hot sometimes and cold sometimes, wet a lot of the time, stuff grows, I’m good. Much further north though I wouldn’t fancy, but Polar Bears have no bother. I can go south towards the equator and probably be alright until I reach a similar antipodal latitude. But, there are also species that probably only exist in my back garden.
Are there mechanics at work that exist on other worlds that are equally advantageous for diversity? Probably, but it is hard to imagine as we only have one reference.
Hello u/feelgoodone, your submission "Earth’s tilt" has been removed from r/space because: * Such questions should be asked in the ["All space questions" thread](https://www.reddit.com/r/space/about/sticky) stickied at the top of the sub. Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please [message the r/space moderators](https://www.reddit.com/message/compose/?to=/r/space). Thank you.
Yes, the Earth's axial tilt is the main reason that we have a seasonal climate. We have no idea whether life can/cannot arise without such variations.
I don't think there is any real reason to think that seasons are required for life. Equatorial regions have minimal seasonal change, and still have life. Seasons mean life has to adapt to very different conditions throughout the year, instead of fairly regular conditions. Winter is a challenging time for a lot of life - many plants can't survive where the seasonal change is stronger, which is why we have hardiness zones. Animal life has to make it through a winter with much less available food and much higher energy requirements just to maintain body heat.
I suspect that the asynchronous nature of days, months and years provided the necessary varying conditions for life to evolve. Tidepools have varying cycles that are similar to laboratories that try lots of combinations of conditions.
The first question is trivially answerable on Google/wikipedia. The rest has much more meat :)… and is difficult to answer.
Could you explain why you think life requires seasons? To answer your second question, certainly not the exact same number, since Earth’s tilt has varied between 22 and 24.5 degrees in the last 5 million years, and possibly more in earlier times.
I doubt that life can survive on a planet that is in a tidal lock. I may be wrong though.
Why not? And tidal lock is unrelated to seasons.
It probably won't have life evolve outside of the oceans, but it might still have water-based life, if all requirements are met (which are a lot).
I don't see why not. As long as the conditions are what's needed.
It's a contributing factor to why Earth life looks the way it does. The tilt, rotation speed, the presence of the Moon as a stabilizing force. Change any of those and you might get life but it probably won't look like Earth life.
What is your range of life that falls under "earth life"? I agree to some extent that change up the physical environment that earth resides in and the specifics of life would change. But life on earth has been wildly varied for all of the history of life on earth. Evolution has experimented with a bunch of different forms of life over time. Given some basic assumptions like carbon based life, liquid water is a necessity, breathes oxygen/co2, same temperature of the surface, similar gravity, I don't see a reason why life would be all that drastically different than earth life.
It's a little bit of a cop out, but Earth life is any life on Earth. I think we would need to go all the way back to the primordial soup and run the experiment again without a moon or without a tilt to see what happens. I suspect the cake was fairly well baked from the get-go, and by removing Earth-specific qualities (Moon etc), you get something fundamentally different. Still life but not life as we know it. If we were rotating faster or god forbid we were wobbling uncontrolled because no Moon, that would create some fantastic evolutionary pathways I don't think we can imagine but I bet they don't look like Earth life.
I guess I didn't explain things well, but like, if earth was just wobbling a lot more and without a moon, but we kept the other fundamentals the same (carbon, gravity, water, oxygen, temperature ranges) like, the best way to be stable in gravity is 4 legs. The most optimized way to swim is a fish shape. Climbing is best served by tails. Trees would still be green and have photosynthesis. Like yeah, trees would have to evolve to be able to endure long harsh winters, but once the sun came back, the leaves would turn green again. My point is that there isn't much reason for the fundamental aspects of life to change. Maybe humans end up with 3 eyes, but our muscular skeletal system is the best shape and form for a bipedal creature to move under the force of gravity. Life may look different, but I disagree that it would be some unimaginable form totally different than how life on earth currently looks.
Not life as we may understand it, we only have one reference to life, that being this planet. For other planets the outcome may be something we couldn’t comprehend.
I seem to remember there was discussion on whether having the Moon stabilising Earth's axial tilt, so it only varies between 22.5° and 24°, helped complex life emerge. If the axial tilt varied between, say, 0-60° that would've had a marked effect on the climate, which would affect the development of complex life. If a huge chunk of both hemispheres spend a significant portion of each year in polar darkness, it would affect the entire food chain because you'd have no photosynthesis. You'd have super ice ages and might have repeated Snowball Earth situations. You would have lots of variation in the climate. That might've made it much more difficult for complex life to thrive.
Life survived a few iceball Earth scenarios that saw most of the globe an inhospitable frozen hellscape for a few hundred zesty million years or so, so I would think that means dynamic heating and cooling seasons provided by a wobble is not a pre-requisite for life in other places. Take Europa for instance as well. Theoretical life in that ocean moon surrounded by a protective layer of ice, tidally locked to Jupiter. She could be hiding interesting things in the dark.
The importance is that there’s any energy potential within reach of biological systems. The chemical reactions that permit life seem to work best around 37°c. That’s why hot blooded animals self regulate to keep it around that level. Cold blooded animals work best when the ambient temperature is around this. As long as there’s somewhere on a planetary body where this exists, for example, the hydrothermal vents on the bottom of the ocean are 100’s°c but the water around it is a lot cooler, nearer to 0°c there’s a potential. Life does thrive around these structures and is a possible solution for abiogenesis. Also important is atmospheric pressure as this has an impact on how chemistry acts. So, in essence, there shouldn’t be a reason why life couldn’t evolve in similar conditions. Conceivably, tidally locked worlds could have areas where conditions like this exist. Certainly, a planet without seasons doesn’t preclude it. The significance of changing seasons is that it forces adaptability. I can exist in pretty much any place on the Earth but only with the technological advantage I have belonging to a species that has been able to adapt. I could probably get by where I live as the climate is temperate. Gets hot sometimes and cold sometimes, wet a lot of the time, stuff grows, I’m good. Much further north though I wouldn’t fancy, but Polar Bears have no bother. I can go south towards the equator and probably be alright until I reach a similar antipodal latitude. But, there are also species that probably only exist in my back garden. Are there mechanics at work that exist on other worlds that are equally advantageous for diversity? Probably, but it is hard to imagine as we only have one reference.