Macroevolution-Do people come from apes?

[Inuyasha]

How can you be a biologist and not believe in evolution? That is the fundation of biology.

[Solid Snake]

You can observe the changes animals have gone through in short periods of time with the records we have from biologists in various centuries. How can you think that these changes werent compounded over millions of years

[Cyranian]

Inu, there are biologists out there who believes in every single word of the Bible, and there are also priests who thinks that evolution might be true. There are different people with different interests in this world.

[biostudent84]

Please be careful with the religious arguments...Chris and I were in a HUGE debate a few weeks ago on this subject and nothing got done. Unfortunately, Chris, our creationistic biologist is no longer here as a result of that. Admin and I went back and deleted the more hostile arguments from that.

We're here to share information and help others...not debate theology =D

Kyle

[junkyarddawg]

Why does everyone frame evolution in terms of "selecting" for survival features.? It is just as easily described as a "culling " process. Nature removes those without the right mix of characteristics needed at any given point of time. Then the only ones left to reproduce are the ones with whatever attributes fit with the current environmental system.

[biostudent84]

"Culling" usually is used to describe selection for a specific purpose. One scientist I've studied heavily opposes the idea that evolution is a process that changes species for specific purposes. Evolution is only the result of natural processes allowing better adapted for survival to reproduce.

Evolution doesn't wake up in the morning and say, "I want a monkey with a bright orange butt." Any trait that evolution selects for is simply a process that by which those orange butt monkeys are better able to reproduce.

[RobJim]

A species has of a fixed number of genes; each one is like a multiple-choice question, like "what color eyes does this organism have?"

There are observed mechanisms by which genes can be copied, so that an animal might have two copies of the same gene.

There are also mechanisms by which genes can be changed.

Combine the two and you get "new genes being created".

Mutating stop codons can increase the length of a gene, which could be interpreted as an increase in complexity.

Retroviruses stick new genes into the genomes of organisms.

These are the sorts of things that can cause a simpler organism to evolve into a more compex one.

[keldo]

It is a proven fact that most mutations are bad. So when a new trait enters the gene pool by mutation most likely it will be a bad one.

[keldo]

Also you were talking about how evolution wasn't solely based on mutations. What other things is evolution based on.

[keldo]

One more think I can't understand about evolution is since human cells are very complex and interdependent then how did the first cell that started evolution form eventually into the human cell. How can something so simple make something so complex when one element needs another to deveope?

[mith]

Where can genes also be acquired from other than mutations:

If you look at bacteria, they swap genes with each other and thus can acquire new traits without sex/mutations. Also if a virus attacks our sperm/egg cells we may pass diffent genes to an offspring.

How can independent cells evolve to become interdependent and specialized:

First off, independent cells can take advantage of their surroundings. If we look at barnacles and some other simple life forms such as jelly fish, the individual cells are very independent but they do work collectively. Notice that only some of the barnacles cling to the anchor and others build themselves into long strands.

Second, interdependent organisms might fuse into one. If you look at a plant cell it contains a motile cell, a cyanobateria(chloroplast), mitochondrion, and a protist nucleus all fused together to form a single organism. Examine a lichen and you might see a fungus and a photosynthetic organism bonding. In the future they may merge into a single organism.

[RobJim]

Keldo -

It is a proven fact that most mutations are bad. So when a new trait enters the gene pool by mutation most likely it will be a bad one.

This is true. The process of natural selection will weed these traits out of the gene pool.

One more think I can't understand about evolution is since human cells are very complex and interdependent then how did the first cell that started evolution form eventually into the human cell. How can something so simple make something so complex when one element needs another to deveope?

Mithrilhack has most of the answer. However, you bring up the idea that each element needs each other, so they must have been created simultaneously. The Theory of Evolution challenges this idea. Do you have a specific example you'd like me to address?