Originally posted by resonance
ok so my question
firstly how does evolution explain things changing from reproducing asexually to reproducing sexually...what did the first thing that reproduced
sexually mate with..
Really all mating is the combination of genes. But the start of life is still the same, the division of cells. Some things still haven't changed
since the start of time. The division of cells in a bag of water. How that exacte division from asexual division to cells having to exchange is not
know, at least not to mean. doesn't mean someone else hasn't figured it out. But I assume that two cells merged together to make a bigger cell. The
combination of genetics made a freaky cell(or I should say an amoeba type creature) that worked.
lso, how did it come about that various species give birth in different ways..inside the body, outside the body
It all started as eggs
being made in the body. Again, some things never changed. Some decided to raise those eggs on the outside, from dinosaurs on down. And others had
those eggs incubate and grow in the womb, like the mammals.But both are the same. The fetus is raised in a capsul.
If you look at pictures of very new fetuses, you can hardly tell a human from an ostrich from a hippo. They all look the same.
the first human-esque creature, did it have an umbilical cord, if not how did the offspring get the nutrient rich blood
Yes, because there was already a line of mammals, that already had umbilical cords. Guess what, eggs have an umbilical cord too. It is a sac of
nutrients that the fetus absorbs while developing. The egg is a neat package that comes with one. In mammals, it is attached to the the package
itself. this seems to be more of the successful forms of reproduction, as the fetus is protected inside the host, and has a longer more abundant
supply of oxygen and nutrients. While an egg is limited and kept outside of the body where it needs much more external protection. Which is probably
why mammals rule.
help me understand what evolution says about these things