Thank you for your help. Actually I was already familiar with a few of the
examples you cite. (One or two I'd been aware of for some time, and naturally I
tried to answer this question with my own resources first.) But here's what I'm
wondering: I know that certain things like eyes and wings have evolved
independently in different species. Did sex evolve independently in plants and
animals? And if it did, in what sense is it the same thing in those two cases?
(Incidental question: What characteristics have plants and animals inherited
from their common ancestors?)
Peace
"Monique Reed" wrote in message
...
| Sex is a whole lot less rigidly male and female than you might think.
| Many flowering plants have flowers with both male and female parts.
| Others have separate male and female flowers on the same plant. Some
| have male and female flowers on separate plants. Some have a mix of
| bisexual and unisexual flowers on each plant. Among plant species that
| have separate male and female specimens, it is not usually a case of X
| and Y chromosomes as in mammals, though that does exist in some
| species. Don't forget, too, that the sporophyte generation of a
| moss, fern, liverwort, or flowering plant has no gender at all. Also
| many species eschew sex almost completely, reproducing entirely
| vegetatively or clonally.
|
| Many animal species are funny sexwise as well--change sex during
| lifetime (certain fish) , reproduce without males (aphids), have
| gender determined by incubation temperature (crocodilians), are
| hermaphrodites (slugs and worms), or reproduce asexually (flatrworms,
| etc.)
|
| Don't even get started on fungi, where there's no male and female per
| se, just different complementary strains of the same species.
| Microbes and algae...well, they do all sorts of different things, some
| of which are just plain weird. And what about that little goober they
| found living on lobster lips--it reproduces by dissolving its own guts
| and rearranging them as young, splitting open and dying to release
| them. I tell you, SF writers have not yet come up with much that
| nature hasn't thought of.
|
| I suspect it's not so much male and female that nature is after, but a
| continuous mixup of genetic material. Asexually reproducing entities
| can skip even that.
|
| M. Reed
| Texas A&M
|
|
|
| Elaine Jackson wrote:
|
| Animal species have male and female specimens, and so do plants. Do plants
and
| animals have a common ancestor that already had specimens of male and female
| gender? Does sexual terminology mean something completely different when
applied
| to plants as opposed to animals? TIA
|
| Peace
|
| --
| ˙WPC5
|