What is evolution but in a way that a 13 year old can understand?

Question

i think it is the type of evolution with plants and animal changing that i need to know the answer to

Answer 1

Survival of the fittest. Those who have the genes of characteristics that enable survival DO. The ones that don't - don't.

Answer 2

Technically defined, evolution is a change in gene frequencies in a population over time.

To explain what this means in actual terms, I need to give you a few definitions:

Gene frequency refers to the proportion of a population with a specific gene for a trait.

A gene locus is the place on the chromosome where the gene for a trait can be found.

An allele is one of the various alternate forms of the gene.

Let's use blood type for example. There are three different alleles, A, B, and O. If you look at your chromosomes at the locus for blood type, you will find one of these three alleles.

Let's say that you have a population that has 30% A, 20% B, and 50% O. In a few generations you come back and the gene frequencies are now 40% A, 50% B, and 10% O. Evolution has occurred in this population because the gene frequencies have changed.

This is, of course a very simplistic example and doesn't address WHY the frequencies changed. There are five main mechanisms by which these changes occurs: genetic drift, gene flow, non-random mating, mutation, and natural selection.

Genetic drift refers to RANDOM changes in a poplution over time. It is most pronounced in smaller populations where the loss of one or two individuals can really affect the gene frequencey. For example, let's say a storm comes through and randomly kills a large number of individuals with the O allele. The population changed, i.e. evolved, but it's not necessarliy more adapted for the environment.

Gene flow occurs when an individual with a unique trait enters the population and adds that trait to the mix.

Non-random mating occurs when individuals chose their mates based on a specific trait which may or may not be adapted to the environment.

Mutation refers to the addition of new traits to the population. For example, a mutation occurs in an individual that causes a new type C allele. Most mutations are neutral do not show any positive or negative influence. Many are harmful and can have negative effects o the survival of an individual if not kill them outright. A very few are positive and give the individual an edge.

Natural selection is a mechanism by which populaitons adapt to en environment over time. Natural selection has 5 fundimental assumptions.

1. There is variation in a population

2. This variation is hereditary

3. Animals in a population produce more offspring than can survive to maturity.

4. Some individuals are more adapted to the environment than others.

5. Those individuals who are more adapted are more likely to survive, to maturity, are more likely to find a mate, and will generally have more offspring survive to have offspring.

In summary, those individuals with traits that are best adapted to the environment with have more offspring than those that are less adapted. Over time, this would lead to a higher frequency of the more adapted trait in the population.

Answer 3

Populations change over time. There are reasons for this, such as something in the environment selecting individuals better to survive. For example, maybe one plant survives better in dry conditions than another plant (this is known as natural selection). So, inherited traits that are advantageous (such as the plant being able to resist dry conditions) would provide a reproductive advantage to the bearer of the trait. The plant that can survive passes its traits on to its offspring, and the plant population continues to evolve. Every population of living organisms is undergoing some sort of evolution. Basically, evolution is always happening!

I'm leaving out a lot of information, such as the importance of genetic variation, mutation, gene flow, and genetic drift, but hopefully this is a start. The websites below can give you more information if you're interested. They are not very complicated and good for a 13 year old.

Answer 4

The basics of evolution are very easy to understand. Of course, like any science, when you get into it deeply it is complicated - but at your level, here's what you need to know.

The idea of evolution starts from the following observations:
1. Organisms vary. You're not the same as your parents, or your friends.
2. Some of that variation is heritable. Even though you're not exactly the same as either of your parents, you do take after them to a certain extent.
3. In nature, resources are limited. There's only a certain amount of food, water and space to live.
4. Organisms can produce more offspring than can be supported by the resources. Animals can have hundreds of children, but sooner or later there'll be too many children and not enough food.

The above observations led Darwin to the conclusion that those animals that are best suited for their environment will tend to thrive, and to produce more children that are themselves more suited to the environment than others. This is known as "survival of the fittest".

Within a population, some creatures tend to be fitter than others. Imagine a herd of antelope, and some lions hunting them. Obviously, in this scenario the antelopes that can run faster are more likely to survive, because they can escape from the lion while the slower antelopes are eaten. The faster antelopes will tend to pass on the genes that helped them survive - fast running or longer legs or whatever it was - to their children, so the next generation will have more of their children than the slower antelopes. Over time, the genes for fast running will tend to dominate.

Those antelopes that run slower of course will tend to leave fewer descendants. So, in time the genes for slow running will tend to disappear from the population.

Over a long period of time, this process of passing on of beneficial genes, and the weeding out of genes that aren't so beneficial, carries on. This is called "natural selection".

Once in a while, a creature will tend to have a very small change in its genes - called a "mutation" - that helps it in some way. Using the scenario above, perhaps an antelope acquires a gene for even longer legs, or stronger muscles. Obviously, the new gene will tend to dominate in the population. Over time, all the animals will eventually end up being descended from the creature with the mutation.

This is repeated over and over again, over millions of years - lots and lots of really tiny changes, each of which is almost unnoticeable in its way, but which add up to change a creature completely.

Hope that helps.

Answer 5

it's very simple, but i tihnk you mean Darwins theory:

He thought that if an animal was more suited to the enviroment, )for this whole thing i am going to use a giraffe as an example.) so the giraffe would be able to reach the higher trees. Now this giraffe would survive, whilst the smaller giraffe didn't get much food so would be weak, the giraffe would mate ;P and then pass his genes(dnt worry about genes) to his children, who would then have long necks, they in turn would survive, and pass on the long neck genes.

Darwin believed this was "natural selection" basically natures way of choosing the animals best suited to eat the tall leaves. This i hope is a straightforward answer and will help you! *cough* best answer *cough* :D if u need more help email me

Answer 6

The most basic definition is a change in a gene pool over time. This is basically a species, or a small population of a species, changing in any way over a period of time (genetically). It should be noted that the individuals don't change, but as they reproduce over and over, the average genes in the population changes.

For example, if you continue to breed a type of dog, but each generation you only keep the biggest dogs, and get rid of the small ones, then you would end up with bigger dogs after several dozen generations.

This is then done over time to produce not only bigger, but faster, stronger, taller, shorter haired, longer snouted, bigger eared, etc, etc, dogs. Then, after even longer, if you compared the dog you have, with the dog you first started out with, they would be different species, even though you are still calling it a dog.

Answer 7

The basic idea of evolution is that plants and animals adapt to changing environments and the most successful of those groups survive and flourish. The so-called survival of the fittest.

Answer 8

The simplest way to explain evolution to you is by starting with a simple fact. Only the strong survive. Charles Darwin who was responsible for introducing the evolution school of thought made it very clear that the reason why plants and animals survive is by evolving to there environments. That is why frogs in N. america with less predatory threats don't shoot poison darts to kill their prey.

In S. America they do because their in the jungle and over time their bodies adjust to the climate and dangers that surrond them.

Same with people why do you think the best marathon runners come from africa. Its because of evolution, we run in normal tempertures and not in the hot african sun and not in the rough terrain that african runners do. They can run better in normal temperatures because their bodies have evolved in their climate to adjust for the hot tempertures.

Answer 9

Take the xample of Darwinian finches
Food is scarce in nature
Birds like the finches have by default been born with beaks that are slightly different to the others so that they can eat different things sosome like nectar and some like nuts and some like caterpillars
now a nut eating bird has athick beak which allows it to eat nuts only
the beaks for bug eating birds is very different and so cant break open the shell to eat the nuts so it leaves them and sticks to bugs
similarly with the nectar eating birds they have long thin beaks so they can suck out the nectar from the plants
in this way each type of bird has food to eat and mates with other birds with the same features so that their young also have those features and can survive

http://www.abc.net.au/science/news/stories/s1688507.htm

Answer 10

A simple, initial answer might be:

Evolution is a set of processes by which plant and animal species adapt to fit their environment.