If Evolution is occuring, then why are there Evolutionary Resistant Species such as the Coelacanth?

Question

There are others: Horseshoe Crab, Nautilus, Crinoids, Cycads, Alligators and Crocodiles. Do they represent the perfection or Pinnacle of their species? I'm looking for information backed by documented sources. Thanks.

Answer 1

There is no time limit on how long a species remains well adapted to its environment. The length of time is random depending on other factors.

Eventually it may have offspring with  mutations that give survival advantages and they may become successful new species and may or may not compete with the original species.

Answer 2

evolution is all about adaptation and change to environment. They actually ARE species, and they are only pinnacles of perfection at the moment.

Answer 3

in addition to the above.. if an environment doesn't change the species stays the same...

i already answered this question thoroughly enough

"evolution needs a drive.. you don't just randomly grow another leg.. unless that provides an advantange..

the environment that the coelecanth lives in has been unchanged for millions of years, and the slight changes that have happened, they've been able to adapt to unchaged (behavioral difference, not physical)

same is true with crocodilians, their niche hasn't changed as such they haven't changed"

http://answers.yahoo.com/question/index;...

you failed to see my answer there.. or are so arrogant with your own point that you felt you needed to post it again

there is no 'pinnacle' or 'perfection'.. only contentment and sustainence..

if the shoe fits... and if it a'int broke...

plate tectonics effects primarily land based animals.. except in such instances as when north and south america were conjoined by panama, where conspecifics are separtated and diverge into new species.. even then the original species remains untill otherwise changed (food source, warming, pH, salinity etc..)

there are and have always been deep water areas of the world oceans.. pelagic fish (such as tuna, mako sharks, and the coelocanth) are least likley to be effected by the seafloor or anything happening on land..

and about the fish thing.. in about 3 days time it'll become not just my hobby but my profession.. i will be a SCUBA diver for the rainforest cafe

sounds like if you need to read anything in particular.. it's about what the terms and conditions for evolution are.. how and why it happens

the chicxulub meteorite hit on land. the crater it created was about 50-50 land sea (at the time anyway) and was eventually filled in by the carribean

even species living some 7,000 miles away offshore of the cape of good hope

would have been  very likely minimally effected..

not to mention the countless other coelocanths in the rest of the indian ocean to the indo-pacific philipines and new zealand, and even wholely pacific japan and even hawaii

the once global coelecanth could have only recently become and indo-pacific species (perhaps due to the Chix. impact half a world away devastating the eastern population)

any resulting turbidity or pH shift (ash) cold have been easily adapted for without a change in appearance

Answer 4

Here's what I answered to a similar question focusing on roaches:

<<Roaches have evolved. The species we have today are not the species that existed millions of years ago. The basic traits and shapes don't seem to have changed much because they haven't been pressured by natural conditions to change. Also, there are insects today that evolved from ancestral roaches. Termites are an example of a modern unroachlike species that evolved from common roach ancestors.

Just because an animal comes from a very old lineage that doesn't seem to have changed much for millions of years does not mean the animals haven't evolved. This is true for everything from the crocodile to the coelacanth. It also fails to take into account all of the species that branched off from the ancestral shapes: like the extinct panzer crocs which were terrestrial hunters and walked on non sprawling legs. They evolved from the water dwelling crocodillians, but were not as successful as their aquatic relatives. Evolution is not a chain of being where one form evolves into the next form. It's a messy, messy branching bush full of dead ends where "change" and "new" does not always lead to long term survival success. Sometimes the families that stuck with the ancestral forms are the ones that endure the longest.>>

No animals are evolution resistant.  If the best adaptive form for an environment is the ancestral form, then newly evolved forms will die off instead of taking over, or will move to other environments and found their own lineages, or share the environment with the ancestral forms as neighbors if they don't compete in a way that leads to only one surviving.  Evolution is not a process of replacement.  Replacement is just a typical result.  Also, just because exterior shapes seem to remain mostly the same, that says nothing about what's going on in the interior.  Mutations occur all the time.  Every human born has an average of around 200 mutations.  Most of these genetic changes do nothing.  They are simply the expected copy errors, sort of like making a fax of a fax of a fax of a fax, etc.  They do result in speciation even if the different species look a lot alike.  The important factor is if they can breed or not.  I guarantee you that modern coelacanth are genetically incompatible with coelacanth from the fossil record.

Ultimately, if you want significantly more in depth information and further reading suggestions, you should try posting your questions here:

http://www.askabiologist.org.uk/

Answer 5

Evolution happens when a species must adapt to survive in its environment. If an animal is already perfectly adapted, and its environment does not change, it has no need to evolve further. This is why some animals have hardly changed in millions of years - they are well adapted to their environments already. They are not 'evolutionary resistant' - they evolved from earlier forms, and could in the future evolve into different ones if environmental pressure demands it.

Answer 6

Evolution is not about perfection or advancement.  It is about adaptation.  When a species is perfectly adapted to it's environment there is no need for change.

Answer 7

Actually, they are evolving, just like everything else, but have changed very little over the course of millions of years. The form they have has been very successful, so creatures with a similar body plan and habits for its environment really don't need to change much in order to survive.