Evolution believers: How does evolution happen?

Question

The way my teachers have always put it, they make it seem like animals who evolve send requests to God asking him for things to make them survive their environments (shells, fur, teeth, poison, ect). I know that isn't how it happens, but thats what all my science teachers make it seem like. So my question is, how do animals evolve and adapt to their environments? Its not like they can manipulate their own DNA so that their offspring come out with an addition to help themselves survive...

Answer 1

Random mutations occur in DNA, either from environment, radiation, or simple errors in replication.

The successful individuals within a population pass down there genes to their offspring.

Answer 2

Okay suppose same specie some animals have 4 hands and the others have 2. Also 4 hands r more useful. In animals, they mate based on how strong the other partner is. Usually a female is selective and she would like to mate with 4 hands male. Their offspring with get that trait, it is not necessary tht the offspring will have 4 hands but will have tht little bit of trait. Maybe 3 legs or something like tht. So with time, as they  reproduce they get 4 legs. Thts how adaptation works

Answer 3

DNA changes all the time, most changes are not advantageous and some are. Some are both at the same time. Take for instance sickle cell anemia trait helps the body fight malaria but has its own harmful effects as well.  Over time these changes are reincorporated in the population threw continued spreading of the trait. Malaria still kills a million people every year there by ensuring the sickle cell anemia trait survives.

Answer 4

Your teachers are teaching you creationism and not evolution.  They are clearly not trained in science or else don't understand the scientific method and the complete inappropriateness of beliefs in science.  In other words, they are lying to you.

Evolution occurs by random mutations (changes) to the DNA of animals and plants.  Most mutations decrease the ability of the life to survive and they die out.  Rarely but occasionally the change to the DNA allows some advantage to the survival of the life.  Over long periods of time an accumulation of small changes will result in a different species developing.  Sometimes the environment changes and with a random mutation, that would have been disadvantageous in the old environment, there is an aid the survival of the life.

No God is involved in the process of evolution.  Evolution is NOT a matter of belief.  It has been verified many times over the last 150 years.  It is the core to modern biology and without it biology is nothing more than the memorization of many unrelated facts.  Evolution is what makes biology a science instead of just a museum collection.

Answer 5

Mutation

Answer 6

Random mutations occur in DNA, either from environmental toxins, radiation, or simple errors in replication.

Mutations that are harmful are removed, neutral ones stick around while beneficial ones are amplified due to the organism's increased reproductive success.

This is natural selection.

Answer 7

>"The way my teachers have always put it, they make it seem like animals who evolve send requests to God asking him for things to make them survive their environments (shells, fur, teeth, poison, ect)."

Whaaa?   If that is what you are getting from your teachers, then either they know *NOTHING* about science and should not be allowed anywhere near a science classroom ... or you are completely (and deliberately?) misinterpreting what they are saying in an absurd way, in order to convince yourself that it is absurd.

The answer is suprisingly simple.

The concept of natural selection goes as follows:

1. All living things have three, *easily* observable features:

a. Variation.  (Members of a species are not identical.)

b. Inheritance. (Members of a species pass traits onto offspring.)

c. Competition. (In any species, more individuals are born than can possibly survive, so there is competition for survival and mating opportunities.)

2. From these three, easily observable features, the following follows naturally:

* Natural selection:  Those individuals born with traits that give some advantage over others of the same species, will pass those traits onto more offspring.

3. So good traits spread in the species, bad traits die out.

4. So the species evolves ... it changes over time.

There is NOTHING in evolution about manipulating their own DNA, or about coming up with traits "on demand".   All traits are just slight improvements on old traits.   This is a slow process, but it is an absolutely *RELENTLESS* process.   Good traits spread.  Bad traits get discarded.   Generation after generation.  Century after century.  Millions of years piled on millions of years.

Answer 8

In its broadest sense evolution is just the change in allele frequencies in a population in response to the environment.  There are two important things to understand in evolution:  variation, and selection.  

There are two very common sources of variation:  mutation and sexual reproduction.  Mutation alters the DNA of an existing gene, creating a new version of it (a new allele).  Sexual reproduction allows traits from different individuals to be recombined in a new way.  Both of these mechanisms work on the next generation: they don't allow a particular individual to change their genes within their own lifetime, it is their offspring that carry the changes.  

A selection is generally any situation where some members of a population will have more offspring than others.  The more offspring an individual has the more fit they are, but remember that being unfit doesn't automatically mean death, it just means fewer offspring relative to the rest of the population.  There are many different kinds of selection based on what the physical mechanism, in nature we call in natural selection, when done by humans we call it artificial selection or sometimes breeding, when done by mating choices we call it sexual selection.

Variation and selection work together in evolution.  Every generation has variation between individuals, producing many new sets of genes.  Selection will then determine which of these individuals are the most fit, allowing them to reproduce the most.  If it helps, imagine that there is a tree branch, and it is constantly trying to grow out in all directions (representing variation), but something comes and repeatedly prunes off most of the branchings (representing selection).  After many generations, many cycles of variation and selection, you can have large differences between the ancestral population and the descendant population.  And note that selection can affect subpopulations differently, this is how we get many different breeds of dogs that all descended from a single common ancestor.