Darwin's views on evoloutinary change known as gradualism and punctuated equilibrium?

Question

Evidence of Genetic Equilibrium and Evolutionary Change Support For Darwin Theory:

I need to compare Darwin's views on evoloutinary change known as gradualism with those of Steven Gould and Niles Eldridge called punctuated equilibrium.

When comparing them I need to explain how punctuated equilibrium enhances and further explains the "missing links" of gradualism,.

Please help me with some input on this!

Answer 1

Punctuated equilibrium suggests the speciation might occur rapidly over a very short period of time.

An example of how this might work could be if you placed a bunch of short critters in a new environment where only the tall ones could reach food. This catastrophic event would probably wipe out most of the critters in the new environment, except for the few freak tall ones. In only a few generations, we may find that all the critters are (comparatively) freakishly tall. The bottleneck of only a few survivors may create all kinds of other changes in the new race, so that after enough generations they become a completely new species.

How this plays into 'missing links' is simple - fossil formation is, at best, a pretty rare event. If it's possible for a new species to form from an old one in a very small time and for the changes to accumulate very rapidly during that time, then it's quite possible that there are simply no fossils formed to find and the 'missing link' will remain forever missing.

Grandualism, on the other hand, would predict that changes tend to accumulate at a steady rate. Every different fossil, therefore, should be just as different as the one before it. If gradualism were true, there really SHOULDN'T be any missing links at all, except in the sense that they haven't been found.

Answer 2

John S.. surly you know there are two types of dinosaurs, the lizard hipped and the bird hipped ... T Rexx being the lizard hipped... so... the birds came from T rexx the liz...oh... that wouldnt work.. would it? .....hmmm,,, scatch that idea

Back to the question.
The problem statement:
We observe micro evolution, a bird becomes a slightly different bird however we do not observe macro evolution, a lizard doesnt become a bird and there is a lack of transitional forms a cow does not become a whale

in walks Steve Gould

Basically Steve Gould throws in the towel and admits the fossil evidense doesnt show the missing links between animal types and asks you to take by faith that it happened only so quickly that you didnt find it. You take by faith that evolution happened and the theory tells you why you see no evidense. Cows really turn to whales he asserts but it happened so fast there is no trace of the inbetween cow-whales

There are other systems, there is also Huxleyism... some animals just won the lotto!! they were in the right place at the right time... he felt

neither theory explains the cases of irreducable complexity where a series of gradual changes would produce a complex thinkg like a flagellar rotor

neither theory explains non life to life evolution

neither theory explains where the original information came from
see In the Beginning was Information by Git

neither theor will expain the complexities of animal symbios and will be grasping at staws trying to do so

The ape to man evolution ... well... the star is Lucy as exibit nuber 1 and if there ever was a poor case for ape to man evolution it would be Lucy and it demonstrated the poverty of the evidense, which Steve Gould is kind enough to remind us of

Answer 3

Darwin's idea of gradual change over long periods of time did not proved out. There are NO transitional fossils. No evidence.
So, Gould and others attempted to rescue Darwin with PE. Punctuated means that evolution behaved differently in the past than it does now. Now evolution happens so slowly that it can not be observed in nature. That is, that now it takes millions of years to see the slightest change. But, in the past it happened so fast that it was un-observable in nature. That is, that macro-evolution was complete (reached equilibrium) in only one generation. Thus-there should be no evidence. And, of course, we see no evidence. The dinosaur produced an egg. The egg produced a Mocking bird. Punctuated Equilibrium.

Answer 4

John S. obviously isn't a geologist. Observing on-going evolution is a hotbed of research for biology types working on their master's or PhD's. This is especially true in the field of reptile studies in the American southwest (and elsewhere).

There are many transitional fossils for numerous genera, but that isn't the issue of punctuated equilibria. The observation is that SOME lineages show rapid changes over short time intervals, while others DO progress in a more gradual sense. Gould, et al., were trying to find a mechanism to explain this observation. Our understanding of modern genetics is key to this. Darwin, brilliant fellow that he was, never had the benefit of knowing about DNA replication or recombination. The German philosopher Haekel (I think) actually proposed the existence of DNA during the late 19th century on purely logical grounds, but it wasn't actually discovered until the 1940s.

Good luck! Hope this helps

Answer 5

Darwins theory of evolution is that species evolve to adapt to their environment over time and gradually evolve into a "new" species or sub species. These changes take millennnia to occur. " Best fit" dictating the survival of the emerging spp or the founder spp. (extinction)

Punctuated equilibrium is a theory in evolutionary biology which states that most sexually reproducing species will show little to no evolutionary change throughout their history. When evolution does occur, it is suggested by this theory, the change in species is faster caused by a split in the genetic line. (eg: Founder effect) that allows a new species to develop whilst the parent species is still present