Sex….The Greatest Lottery on
Earth. This title is an extremely fitting for this chapter discussing sex. Why
take the chance of reproducing sexually rather then simply cloning your
offspring? Lane describes the two-fold
cost of sex explaining, “A race of cloning females ought to double in numbers
every generation, wiping their sexual relatives from the population in a matter
of a few generations.” If this is the case, then why does sexual reproduction
persist? It has become quite obvious to
biologists over the years that sexual reproduction must provide extremely
beneficial benefits in order for it to be prevalent in living organisms
today. Sex provides the ability to bring
together the best combinations of genes in individuals, eliminate detrimental
mutations, and incorporate any valuable innovations. Despite all the biological costs that go into
sexual reproduction, this method of reproduction allows for diversity that can
quickly escape from deleterious mutations.
Natural selection acts on populations to ensure only beneficial
mutations persist in a population while deleterious mutations die out. As well as explaining how sex evolved in the
first place, Lane also explains how sexual reproduction evolves and continues
today. The red queen hypothesis, a major
hypothesis for the maintenance of sex, is based of the quote, ‘It takes all the
running you can do, to keep in the same place.’ Species are locked in competition and
perpetually racing against each other, never staying ahead for long. This competition between species always fuels
the evolution of organisms thorough sexual reproduction to allow for variation
to outcompete other species.
Overall, I found this chapter on
sex to be very interesting because it connects to what we have been learning
recently in class. So far this has been
one of my favorite chapters to read because the evolution of sex is
fascinating. Originally, it seems
ludicrous for sexual reproduction to evolve in the first place. However, once looking at it from the
perspective of variation and diversity acted on by sexual selection to
eliminate harmful mutations…it all makes sense.
I am definitely thankful for the evolution of sexual reproduction
because without it I would not be here today.
I like your description of sex as constantly changing the organisms that practice it. I think its very cool to think of an arms race between sexually reproducing organisms and asexually reproducing organisms. It is an interesting idea to think of our species in competition with bacteria in this manner with the final outcome of the arms race undecided.
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ReplyDeleteI really like your interpretation of sex and how it connects to what we have been discussing in class. I agree with your perspective of how variation and diversity is truly fascinating and helps clear the questionable reasoning of sex to evolve in the first place. I have not read this book but your quote, explanation, and relation to class really intrigues me and I hope to one day read the book as well.
ReplyDeleteCelina,
ReplyDeleteI really like your synopsis on this chapter in the book. I found it quite compelling as well. In relation to my post about flaws in the genetic code, it seems as if sexual reproduction evolved as a mechanism that responds to the code's degeneracy. As you said, "Sex is what allows the best combinations of genes in individuals, eliminate detrimental mutations, and incorporate any valuable innovations". Those "valuable innovations", as I read from earlier in the book, are areas of opportunity that the code has presented to be optimized by natural selection.