Two types of single-celled bacteria merge to make a more complex cell.
After all, those bacteria were extremely efficient in passing along their genes to future generations. In their billion years or so of the Reign of the Prokaryotes, they had spread everywhere the oceans took them and even up onto some land masses. If the name of the game is successful reproduction, it sure looks like the prokaryotes had the upper hand. Nothing was broken; why fix it?
In the dog-eat-dog evolution that most people connect with Darwin’s theory, why would two successful and independent bacteria species give up their independence by cooperating to produce a new cell? Why not just keep reproducing their own stuff?
The cause is not explained by Darwin’s mutation followed by natural selection. Teamwork is the agreed-upon cause. Evidence shows that the new eukaryotic cell is clearly related to the two single-celled organisms. Maybe one species used the other as meal, but whatever caused it, symbiosis is the term used for a merger like this – an event that happens when one organism needed something the other organism had. At this time, the environment may be been nearing a Snowball Earth time. Maybe the two organisms needed this merger to stay alive.
What caused the two genders to separate within one of those more complex cells?
Science can tell you everything you want to know about inheritance of traits. But if there exists a scientific answer to the question, “How come the material making up the two genders separated in that cell?”, this researcher’s efforts failed to find it. However, one can find a lengthy list of why this SHOULD NOT have happened. Reasons:
- Sexual reproduction makes the process less efficient. The result: it burns up more energy than just splitting into two new cells.
- Look at the complication this adds to reproduction. Bacteria just split cell – and that’s it! The more complicated way: that egg floating around needs a mate.
- That mates uses energy to get there. That energy might be better spent just splitting like the prokaryotes did.
- Connecting with a mate brings in the idea of competition. Over time, females invest a lot of energy into being the most attractive so a male is drawn to them.
- Two genders exist but only one reproduces. The other half does not reproduce.
My statistical side is screaming at me, “No. Genders were not necessary. The deck was somehow stacked to help guide that sorting!” What caused the two genders to become separate from one another?
“The deck was stacked.” How? Science has pretty much agreed on this: each little step depends on and draws from that which existed before. Keep that mind through this review of the steps to here.