Question

The popular media often portrays evolution as being predictable with a definite goal. For instance, in one Star Trek Voyager episode, the captain instructs the ship’s computer to extrapolate the “probable course of evolution of hadrosaurs (a bipedal dinosaur) if hadrosaurs had been removed from the Earth before the K-T extinction and allowed to evolve on another planet.

A) Is it theoretically possible to accurately predict the long-term course of evolution? Explain your rationale.

B) What information about the hadrosaurs and their new environment would be useful for making the best possible prediction?

Answer 1

A ) Ans: No

* The 3 words in this question - theoretically, accurately, long term - are making it impossible to give a positive answer.  

* In evolution studies, experimental studies and observational research has helped a lot more than the theory alone to arrive at conclusions.

* we can never 'accurately ' predict an evolutionary pathway due to many factors influencing the evolution.

* predicting evolution for a long period of time is again difficult, since the various factors affecting evolution will change unpredictably over a long period of time.

* 5 main forces influenced human evolution are natural selection, random genetic drift, mutations, breeding patterns, social and cultural influences.

* Genetic drift and mutations are highly unpredictable. One mutation may not be favoured initially, but in a later period it may be favoured strongly and may become dominant in the group.

* Evolution doesn't not have a pre set or definite goal. Evolution doesn't support the largest, strongest, fastest or fairest individuals but it supports the "fittest", remember the survival of the fittest.

* The environment will change drastically over time, according to that feeding, breeding and cultural patterns , mutations etc will vary. The fittest individual in the changed environment will survive and evolve.

* since we can't predict all these factors accurately, evolutionary pattern also can not be predicted accurately.

B) Ans: Hardosaurus were herbivorous, bipedal dinosaurs with a special predentary bone.

To predict the evolution of Hadrosaurus, first we have to know about its evolutionary history, ie:- from which group they evolved into a new species, how much time was taken for that, what were its feeding and breeding behaviours, how much its physical stature changed over time.

Suppose they were saved from K-T extinction, and introduced into a new place, their evolution there will again depend on natural selection, genetic drift, mutations, breeding patterns and social interactions.

Lack of availability of plant forage may make them evolve into omnivorous or even carnivorous type over a period of time with the help of adaptations and mutations.

If the new environment favors highly intelligent hadrosaurus, they will evolve into more intelligent creatures, if more intelligent forms are not favoured in the new environment, they will evolve into far less intelligent creatures than the beginning.

Thus the evolution of Hadrosaurus in a new environment will depend on the "survival of the fittest" in that new environment and the final form can not be predicted with complete accuracy, since factors such as mutation and genetic drift play a major role, which are relatively highly unpredictable.