Thanks for the reply.
Just a few little things I want to ask about (your right, I am interested
in this stuff, or I wouldn't be here!).
>>I have doubts about how and why an organism would change from asexual
>>reprodution to sexual reprodution.
>
>Here is how it happened in one lineage:
>
> In Volvox, almost all the cells are somatic, and very few of the cells
>are able to produce new individuals. In some species of Volvox,
>reproductive cells, as in Pleodorina, are derived from cells that
>originally look and function like somatic cells before the enlarge and
>divide to form new progeny. However, in other members of the genus, such
>as V. carteri, there is a complete division of labor; the reproductive
>cells that will create the next generation are set aside during the
>division of the reproductive cells that are forming the new individual.
>The reproductive cells never develop functional flagella and never
>contribute to motility or other somatic functions of the individual; they
>are entirely specialized for reproduction. Thus, although the simpler
>Volvocaceans may be thought of as colonial organisms (because each cell is
>capable of independent existence and of perpetuating the species), in V.
>carteri we have a truly multicellular organism with two distinct and
>independent cell types (somatic and reproductive), both of which are
>required for the perpetuation of the species. Although not all animals set
>aside the reproductive cells from the somatic cells (plants hardly ever
>do), this separation of germ (reproductive) cells from somatic cells early
>in development is characteristic of many animal phyla and will be discussed
>in more detail in Chapter 7."~Scott F. Gilbert, Developmental Biology
>(Sunderland: Sinauer Assoc. Inc., 1991), p. 18
>**
> "What happens to the somatic cells of the 'parent ' Volvox now that its
>young have 'left home'? Having produced offspring and being incapable of
>further reproduction, these somatic cells die. Actually, they commit
>suicide, synthesizing a set of proteins that cause the death and
>dissolution of the cells that make these proteins. Moreover, in this
>death, the cells release for the use of others-including their own
>offspring- the nutrients that they had stored during life. 'Thus emerges,'
>notes David Kirk,'one of the great themes of life on Planet Earth: 'Some
>die that others may live.'"~Scott F. Gilbert, Developmental Biology
>(Sunderland: Sinauer Assoc. Inc., 1991), p. 20-21
My real question on this side of things is about the change from one type
of reprodution to another. ie if a creature was reproducing without any
need for another creature to be involved, how did it become advantageous to
need another? And how did it occur that all of the sudden a sex cell with
only half the needed chromosomes came into being and survived? And did
another creature happen to have the same problem at the same time, and
these two mutated half cells bump into each other and form a whole knew
creature with the genetically inherited trait of making the occasional half
cell? I don't really understand how this could happen.
>And how something would evolve from
>>laying eggs in water to laying eggs on land, to not laying eggs at all!
>
>Each form of reproduction works in the peculiar environment to aid in the
>survival of the species.
Lets imagine an amphibian, who lays eggs in the water. How would this beast
change from laying eggs in the water to laying eggs on land? The structure
of the egg would have to change, the baby would have to change to be able
to escape the new type of egg, the babys would have to be able to handle
the land, and the egg laying process would have to change....
Could all this happen in one go? If not, what kind of changes could bring
this about?
>>And why do bird have pretty colors? This is attractive to other birds, but
>>it would also make them obvious to preditors.
>
>Not necessarily. Sometimes what we see as pretty colors are not the same
>frequencies that the eyes of other species see.
>
>Wouldn't natural selection
>>have made animals attracted to each other for qualities like camoflage,
>>strength and speed, not things like a huge stupid peacock tail that slows
>>you down?
>
>Then why did God create the stupid peacock tail feathers?
I believe in a God who likes beauty, thats why we have art, because out
creator has made beauty and made us to appreciate it. Peacock feathers are
rad, I think they are heaps beautiful, and I'm sure God made them with that
in mind.
>>
>>All these things are only secondary of course, and someone probably has
>>thought of an answer, but I'm not really concerned about how it happened,
>>the only thing I am concerned about is the fact that every day people are
>>dying without know about Jesus. I think that stinks.
>
>I agree that people dying without Jesus stinks. But so does Christians
>becoming atheists because other Christians decide that they won't pay any
>attention to science! And if you aren't concerned with HOW it happened,
>what are you doing on this list?
You got me there, I think what I meant is I'm not that opinionated yet, I
don't have enough reason to be dogmatic either way, as there are problems
with both arguments. I don't know everything about the universe, and I dont
thing the sum of human knowledge really knows that much either. Science is
a changing thing, as we discover new stuff, our ideas change. Makes life
more fun, I think, we will never know everything, so we can have fun trying
to thing of whats really going on in the universe.
Donald
____________________________________________
Donald Howes
Acting Research Systems Co-ordinator
Research Services
University of New England
Ph 6773 3263
"I am not ashamed of the gospel, because it is the power of God for the
salvation of everyone who believes" Romans 1:16
_____________________________________________