What made us live in a house?

[Willtor]

Let's take the lung fish as an example. The lung fish stays for a while in land environment (I am not sure what is the % of time) in its "normal" life activity. If the predators on land is a real threat, then the lung fish should not even exist at all. In other words, the lung fish has already survived its first step of "landing". So, even the predator is a threat, the evolution of lung fish should be able to continue onto its second step.

Again, it doesn't have the idea of becoming a land-dwelling creature in mind. It spends time out of the water because its habitat dries seasonally. This is not a land-dwelling creature.

 

[juvenissun]

A more generalized question:

The (surficial) environment of earth changes at a slow pace. The question is: why would any life species want to resist the environmental change by not evolving itself?

An example is that human lost his hair due a slight change of living habitat. It is a pretty fast pace and a very sensitive way of evolution. If environmental change is the ultimate control of evolution, then why would some lives resisted the change?

 

[metherion]

The question is: why would any life species want to resist the environmental change by not evolving itself?

This displays several fundamental misunderstandings about evolution.

Nothing 'chooses' to evolve. It just happens. Nothing chooses how to evolve. It just happens. Nothing chooses to resist evolving. It just happens. Furthermore, an individual life form does not evolve. The population evolves based on the mutations of the individual life forms.

Metherion

 

[juvenissun]

This displays several fundamental misunderstandings about evolution.

Nothing 'chooses' to evolve. It just happens. Nothing chooses how to evolve. It just happens. Nothing chooses to resist evolving. It just happens. Furthermore, an individual life form does not evolve. The population evolves based on the mutations of the individual life forms.

Metherion

So, why didn't evolution happen in many species over tens or hundreds of millions of years? They have no reason not to evolve.

 

[Willtor]

So, why didn't evolution happen in many species over tens or hundreds of millions of years? They have no reason not to evolve.

It isn't about reasoning to evolve. Species evolve if environmental pressures favor certain traits. If you're referring to sharks, there has been little pressure to change for millions of years. They are so good in their niche that changes just aren't helpful for causing them to pass on their genes. Besides sharks, I'm not aware of any group of species that has changed so little for so long.

 

[gluadys]

Wonderful. Thanks. It makes me feel like snake is evolved from lungfish.

Well, when you remember that evolution makes a branching pattern there is a relationship but not one of direct ancestry. Think of a modern lung-fish as the descendant of a long-ago lung-fish living contemporaneously with early tetrapods like Tiktaalik. Tiktaalik or some creature very like it is the ancestor of two groups: amphibians and amniotes. And snakes are part of the amniote family, just like you and me.

Early lung-fish and early tetrapods would also share a common ancestor further back in time.