The evolution of animals?

Question

ok, so if we all evolved from like slime whatever (idk) how is it that animals are all so different? i dont get how all people and animals if we basically all evolved from the same thing are so different looking.

i am a creationist. im just curious.

Answer 1

Very subtle changes add up, over time, to make large changes.  These sublte changes can happen each generation, and the process has been going on for billions of years.  How long is a generation for most life forms?  Let's throw out a long number for the length of one generation - let's say 20 years.  That means that there are 50 generations in a thousand years, 50,000 generations in a million years, and 50,000,000 generations in a billion years.

50,000,000 subtle changes result in wonderous diversity.

Answer 2

listen to tyrosine, he knows his stuff and is current

Answer 3

The great thing about modern genetics and evo-devo is that we can see just how similar all of the disparate animal forms we observe are. The evolution of diverse animal forms are all the result of the presence of genes which control development. However many of these "master" genes are present (largely unchanged in code) in all animals, even between vertebrates and invertebrates. It is small changes in regions which regulate these genes that allow for changes in form. Over millions of years of mutation and ecological influence we end up with marvellous innovations.

Also, that "slime" you mentioned shows far more diversity than animal groups. In one handful of soil you'll be holding bacteria as distantly related to one another as are a zebra and a cactus. In comparison we are very very similar to other animals.

What's important here is that appearances can be deceptive. Many biologists thought there would be drastic differences in the genetic make-up of distantly related animal groups; but when you look below the surface, at how these animals are made, there's a remarkable similarity.

Answer 4

Isolated populations living in different environments, with different selection pressures, produced different animals over a very long period of time.

Thanks for asking.

Answer 5

Well, no one ever said we evolved from slime, that's a "straw man fallacy" similar to the equally untrue "Darwin said we evolved from monkeys".

What evolution does state is that over generational time there will be gradual change. Some of these changes will be deleterious, and the individuals that have them will be at a competitive disadvantage, and are less likely therefore to have offspring. Some changes will be advantageous, and will give individuals that have them an advantage in survival. These individuals will be more likely to survive and have offspring. You must always remember that advantage is relative: What is an advantage under one set of conditions may be disadvantageous under other conditions.

The process is slow, you will not see it over one or even a few generations.

Also, you may be surprised to know just how similar all living things are. A good example is the protein RecA. RecA is involved in DNA repair and recombination, and is found in all living cells. Despite 2 billion years of divergence between humans and E. coil (a bacteria), RecA is still ~65% the same between both species. In fact E. coli RecA will function normally in mammalian cells. Now, I see this as evidence to suggest that at some distant point in the past humans and E. coli share a common ancestor. You, a creationist, might see this as proof of creationism (same mechanism, vastly different species), however I would like to point out one thing: If all species today were created "as is" by God, and do not under go change, then why is there any difference at all between human and E. coli RecA? Between both species function is maintained, therefore the only logical explanation fro any difference is random change over time.

Answer 6

If you think about it, you are not actually *that* different from (for example) a cat:

You have the same number of limbs, the same number of eyes, nostrils, etc. You even have the same number of vertebrae in your spine.

You are *much* more similar to a cat than either you or the cat are to an octopus, or a rhodedendron, or a bacterium.

And that is because you are much more closely related to the cat than you are to those other organisms.