In the evolution of animals, how the animals grow itself for adapting the environment?

Question

Is external factor made animals or animals felt or thought about that and evolution helped for this.

Answer 1

Darwin proposed 'survival of the fittest'. Biologists who survive can communicate their ideas, theories, results, and questions. They work at it. They prepare by learning well the language in which they will work.

Darwin did not require conscious understanding of his evolutionary winners. The tigers whose genetics made them better predators survived and breeded further. They didn't need to know why. Same for the chameleons which best mimicked their surroundings.

Answer 2

I feel that everyone so far has failed to answer his specific question, though the aussie did a great job of explaining natural selection. What this person is asking is "how did the giraffe's neck get larger in the first place?"
The answer is through genetic mutations. Proper breeding can only create animals which are the best combination of what the population of animals already have. In order to truly become better at surviving, you need one of more individuals with new traits that have never been seen by that population of animals. When the DNA is copied to make the sperm or eggs, there are always a few errors. Almost always these errors have no effect. These errors are also much more likely to be unfavorable and thus be a disadvantage rather than an advantage. But rarely these mutations produce a trait that increases the survivability of the individual that was lucky enough to be born with it. One may ask if this is a rare event, how could evolution have happened? Over millions of years, these rare events have had the time to happen billions of times. Now following the Aussie's explanation you can see how this trait becomes more prevalent in the population.

Answer 3

Some may be by genetic mutation, some by the trial and error and some by external factor.

Genetic mutation: Every so often, there may be some mild degree of genetic mutation in animal offspring. Sometime, the mutation works for the better results, sometimes, it work against the new offspring. Some of the changes may works better for new environment and sometimes it makes it less competitive.

For an example, plague killed millions of people in Europe during the middle age. Some people did not get sick even they were exposed to the diease. Later they found that there is a genetic mutation/defects of their gene that keeps them from getting sick by the plague. There is a threat for extinction, but some just got luck to have mutated gene and stay alive.

Animals body has some build-in adjustment system to adapt to changes. For example, if you aways rub your knuckle against touch surface, first you will have a open wound if you rub it hard enough, then when the wound heals, the skin over the knuckle will become tougher and thicker. The body will somehow make necessary changes to provide better protection. Bodies of animal continuously making adjustment to these external environments. And if these help making the animal stronger, more successful, it will pass on the gene to next generation. If the changes does not help, the animal may died short and fail to pass on their changes to next generation

Answer 4

Evolution was not a conscious effort, it was merely a response to new environmental pressures. The successful animals were selected for through random selection due to their genetic diversity. Since we are all genetically diverse... we are not all clones of one another, our genes differ slightly... some of us it seems that our genes differ greatly. So, say that rabbits come in white, black, and brown fur. Also, some rabbits have thicker fur than the others. Over time an ice age ensues and there is snow covering this area where the rabbits are for a long time. Eventually the white rabbits with thick fur will be the dominant animals over the black or brown or short-haired rabbits due to the new environmental pressures. Now further down the line, say some of the rabbits can digest bugs, or even small shrews, and some rabbits have sharper teeth than the others. Well, now in the absence of enough plant material to eat, these rabbits will survive and so then rabbits you see will have sharper teeth and will eat some meat... And so on... this goes on VERY slowly with small changes all depending on the environmental pressures at the time.

Our evolution is thought to have arisen from the forest turning into the Savannah in Africa. We no longer lived in trees, but walked great distances across the flat plains where it was beneficial to stand erect to see for greater distances over a flat area.

Answer 5

G'day Arthur K,

Thanks for your question.

Adaption is done through natural selection. Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce. Natural selection works on the whole individual, but only the heritable component of a trait will be passed on to the offspring, with the result that favorable, heritable traits become more common in the next generation. Given enough time, this passive process can result in adaptations and speciation (formation of new species).

The term was introduced by Charles Darwin in his 1859 book The Origin of Species, by analogy with artificial selection, by which a farmer selects his breeding stock.

A well-known example of natural selection in action is the development of antibiotic resistance in microorganisms. Antibiotics have been used to fight bacterial diseases since the discovery of penicillin in 1928 by Alexander Fleming. However, the widespread use and especially misuse of antibiotics has led to increased microbial resistance against antibiotics, to the point that the methicillin-resistant Staphylococcus aureus (MRSA) has been described as a 'superbug' because of the threat it poses to health and its relative invulnerability to existing drugs.

Natural populations of bacteria contain, among their vast numbers of individual members, considerable variation in their genetic material, primarily as the result of mutations. When exposed to antibiotics, most bacteria die quickly, but some may have mutations that make them a little less susceptible. If the exposure to antibiotics is short, these individuals will survive the treatment. This selective elimination of maladapted individuals from a population is natural selection in action.

These surviving bacteria will then reproduce again, producing the next generation. Due to the elimination of the maladapted individuals in the past generation, this population contains more bacteria that have some resistance against the antibiotic. At the same time, new mutations occur, contributing new genetic variation to the existing genetic variation. Spontaneous mutations are very rare, very few have any effect at all, and usually any effect is deleterious. However, populations of bacteria are enormous, and so a few individuals will have beneficial mutations. If a new mutation reduces their susceptibility to an antibiotic, these individuals are more likely to survive when next confronted with that antibiotic. Given enough time, and repeated exposure to the antibiotic, a population of antibiotic-resistant bacteria will emerge.

A similar process occurs over time occurs in all living themes in seeking to adapt to their environment.

I have attached some sources for your reference.

Regards

Answer 6

This happens through selective mating. Certain traits become dominant as their desirability is translated into more and more matings and off-spring. After surprisingly few generations, big changes can occur. This is even present in humans; as a species we're getting taller. That is because more females are choosing taller mates.