Evolution for Beginners

[Hydra009]

We should also try to inform people that fitness is not some absolute quality, but relative to the prevailing local conditions, which often change.  Adaptions that work in colder climates fail in warmer climates and vice versa, being tall can be an asset in some circumstances but a detriment in others, etc.

[Unbeliever]

Yeah, s'more like survival of the luckiest!

[eylul]

Today i hated evolution. I have learnt pigs cant see the sky because of their physical situation. I want to hug them all and show them to sky :/

[TomFoolery]

We should also try to inform people that fitness is not some absolute quality, but relative to the prevailing local conditions, which often change.  Adaptions that work in colder climates fail in warmer climates and vice versa, being tall can be an asset in some circumstances but a detriment in others, etc.

Agreed. And also that things don't "devolve" per se. Things evolve in one direction only, and sometimes to the detriment of a species, but that doesn't mean it's reverting back to some previous form.

[Hydra009]

Yeah.  "Devolve" is a meaningless term brought about by a fundamental misunderstanding of evolution - that it has some ultimate goal and the species in question is evolving in the opposite direction.  Meanwhile in reality, evolution is just genetic change.  There's no such thing as reverse evolution.

[Summertimeyeah]

Where did the first living thing come from?

[Summertimeyeah]

Before animals evolved plants evolved. where did the plants come from? What was the first animal? Did insects come before animals? What was the first insect?

Why have things only evolved on earth, how come there isn't any plants or suitable life on other planets. Like how come nothing has evolved on the sun?

[Hydra009]

Where did the first living thing come from?

You're talking about abiogenesis, which is separate from evolution.  You can read up on that here.  The jist of it is that fairly simplistic (compared to modern bacteria and eukaryotic cells) self-replicating molecules gave rise to the first cells.

[Hydra009]

Before animals evolved plants evolved. where did the plants come from?

Green algae.

What was the first animal?

Unknown.

Did insects come before animals?

Insects are animals.

What was the first insect?

Unknown.  Here's the oldest one that anyone knows of. 

Why have things only evolved on earth, how come there isn't any plants or suitable life on other planets.

Obviously, favorable conditions for life were not sustained on nearby planets.  There might be some traces of life elsewhere in the solar system, but the Earth is definitely the mother lode.

Like how come nothing has evolved on the sun?

[Summertimeyeah]

You think that things can't evolve on the sun is wrong.

[Termin]

You think that things can't evolve on the sun is wrong.

Here's the thing, life can evolve anywhere life can survive.

If there is a form of life capable of living on the sun , we are not aware of it, and probably never will be as we are only able to observe the sun at a distance, and only very carefully, as we have no way to physically examine the sun. 

  I am curious however why do you think life can evolve on the sun and what you base that upon ?

[Hijiri Byakuren]

Before animals evolved plants evolved. where did the plants come from?

Probably some form of chlorophyll-producing protozoa.

What was the first animal?

Impossible to know. It would have been an invertebrate, and they rarely leave fossils.

Did insects come before animals?

Insects are animals.

Why have things only evolved on earth

We don't know if Earth is the only place with life.

how come there isn't any plants or suitable life on other planets

We don't know one way or the other. Also, this has nothing to do with evolution. The formation of life from non-life is abiogenesis, not evolution.

Like how come nothing has evolved on the sun?

You have no way to know whether or not something evolved on the sun. It's difficult enough for us to even look at the sun, much less determine if something lives there.

[Hydra009]

You think that things can't evolve on the sun is wrong.

Just out of curiousity, what sorts of chemical reactions do you surmise are taking place on a very hot and heavily pressurized (understatement) ball of what is almost entirely hydrogen and helium?

[TomFoolery]

You think that things can't evolve on the sun is wrong.

Just out of curiousity, what sorts of chemical reactions do you surmise are taking place on a very hot and heavily pressurized (understatement) ball of what is almost entirely hydrogen and helium?

Agreed. The sun is essentially a nuclear reactor.

However, it is true that life can evolve in some pretty spectacular places. Extremophiles on Earth are a great reason to believe life could possibly exist on planets incapable of supporting most other Earth life, thanks to the nature of their perfectly evolved enzymes. Yet we call them extremophiles from our own human perspective. There are organisms alive on Earth flourishing in the presence of high levels of ionizing radiation, in environments completely deprived of oxygen, in under alpine snowpacks at temperatures below -15 °C and in hydrothermal vents. Yet even in hydrothermal vents, where the temperature reaches around 122 °C (251.6 °F), still doesn't even scratch the sun's surface temperature of 5500 °C (9940.73 °F).

But I would say the fact that even these creatures exist should open our mind's to the possibility that there could well be life on planets that are too cold, hot, acidic, basic, etc. to support human life.

[PopeyesPappy]

Just out of curiousity, what sorts of chemical reactions do you surmise are taking place on a very hot and heavily pressurized (understatement) ball of what is almost entirely hydrogen and helium?

Nuclear molecules that bind elements via the exchange of neutrons instead of electrons like we see in conventional chemistry were first observed in the 1960s. All observations to date have shown them to be unstable and short lived, but the higher pressures and energies found on the surface of stars could affect that in ways we don't understand. The bottom line is energy based life forms are a possibility that have been a subject of discussion for decades. Carl Sagan and Degrasse Tyson both admit the possibility. It is a big ass universe and there might be a lot of things happening out there that our limited understanding of how things work currently tells us are improbable.