You are here:

Evolution/why no evolution for survival

Advertisement


Question
Hi,

I read that cuttlefish mostly have only one mating season and they soon die after mating. Why didn't adaptive mutation take place so that its survival is ensured even after mating. The same is the case with the worker bees. Also virus/bacteria had been in the earth for billions of years yet they did not seem to have evolved to a higher/visible beings. Can you please explain.

Futhermore, if an organism survives, how does the information that enhances its survival gets passed to the genes so that it can be transferred to its offspring.

Regards

Answer
Dear Amtry,

The simplest answer is that once an organism has reproduced, natural selection on traits that are expressed after that are sort of moot.

One might wonder why certain human lineages have genes that promote certain types of cancer.  Why don't we "evolve away" such maladaptive mutations?  Bottom line:  The effects of those genes usually don't kick in until the people carrying them already have had children.  So the genes are passed on with that unfortunate future.

Also, organisms do not evolve traits because they "need" them.  Genes govern the life cycle of any organism, and if those genes can "get themselves" into the next generation successfully, that's all that matters to the gene.  If you are not familiar with the Selfish Gene Theory, please see:

http://en.wikipedia.org/wiki/The_Selfish_Gene

Also see:

http://evolution.berkeley.edu/evosite/misconceps/IDtrying.shtml

for a nice, clear explanation (complete with cute drawings.  Thanks, Berkeley Museum of Paleontology!) of why the idea that organism evolve traits because they "need" them is a misconception.

I hope this helps.

Dana  

Evolution

All Answers


Answers by Expert:


Ask Experts

Volunteer


Dana Krempels

Expertise

I can answer questions about evolutionary mechanisms and theory, including genetic drift, mutation, natural selection, etc. I also can clear up misconceptions about evolution as it's sometimes talked about by those not well-versed in the subject (e.g., some politicians and many religious fundamentalists).

Experience

I have a Ph.D. in Biology, and presently teach Evolution and Biodiversity, Genetics, Botany, and Zoology at the University of Miami.

Organizations
House Rabbit Society Beta Beta Beta Biological Honor Society

Publications
Exotic DVM Magazine (veterinary journal)

Education/Credentials
B.S. in Biology B.A. in English Ph.D. in Biology

©2016 About.com. All rights reserved.