Question

What definition do we use to describe the term evolution? 2) Darwin, among others, observed that populations tend to produce more offspring than can be supported by the environment what is the significance of this in relation to evolution? Use an example to support your answer. Humans possess many vestigial structures, listed below. Choose two from the list, describe what they were once used for, and why they became vestigial.
i need each answered correctly

Answer 1

1. Evolution:

The process in which changes occur in an organism at gene level,phenotypic(externa features)level through the events like mutation,gentic drift and natural selection over the course of time can be termed as evolution.

Evolution is merely a change and all the time an organism evolves it does favour it sometimes it is lethal i.e it leads to death of the organism.But we always hear evolution brings many advantages to the species on the whole as only the ones with changes which offer benefits survive and thrive in the long run.

e.g. Resistance of bacteria towards antibiotics and this is by evoulution at gene level.

2. Organisms often produce more offspring than can be supported by the environment.

• Often the environment is not suitable to the offspring and most of them die due to various ailments disease,starvation,get eaten by predators.
• For the species to evolve first of all they need to survive,evolution part comes later.
• e.q.Rabbits produce around 50 baby rabbits in six moths of time: Red back spider lays 3000 eggs in one batch.
• Imporatnt point to be noted is only the organisms which encounter unfavourable conditionsand have less probability of survival produce highest number of offspring with short gestation periods and the organism like human often produce very less offspring with longer geststion.

3.Vestigial organs are those which were functional in an ancestor but doesnt hold any function in the descendant still they appear in a rudimentary form or reduced form.

• Wisdom teeth- They were very useful in early man when the diet was raw meat,leaves,roots and these wisdom tooth increase the chewing ability.
• Coccyx-Human tail bone is a remnant of mammalian tail often seen in monkeys used for balancing and signalling when they were walking on their four legs. But now in human we dont have a tail still we do have a coccyx bone.
• Ear muscle- In monkeys ears posses many muscles helping them move ears in various directions to listen to any threat.In humans they are not very useful but still they are present.
• Body hair- Hair is needed for keeping the organisms warm as we all know human have established in various environments and not a very fuctional.